Merge #5750

5750: Rename ra_ide -> ide
 r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <[email protected]>

54 files changed, 23586 insertions, 0 deletions

diff --git a/crates/ide/src/call_hierarchy.rs b/crates/ide/src/call_hierarchy.rs
new file mode 100644
index 000000000..58e26b94c
--- /dev/null
+++ b/crates/ide/src/call_hierarchy.rs
@@ -0,0 +1,393 @@
+//! Entry point for call-hierarchy
+
+use indexmap::IndexMap;
+
+use hir::Semantics;
+use ide_db::RootDatabase;
+use syntax::{ast, match_ast, AstNode, TextRange};
+
+use crate::{
+    call_info::FnCallNode, display::ToNav, goto_definition, references, FilePosition,
+    NavigationTarget, RangeInfo,
+};
+
+#[derive(Debug, Clone)]
+pub struct CallItem {
+    pub target: NavigationTarget,
+    pub ranges: Vec<TextRange>,
+}
+
+impl CallItem {
+    #[cfg(test)]
+    pub(crate) fn assert_match(&self, expected: &str) {
+        let actual = self.debug_render();
+        test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_render(&self) -> String {
+        format!("{} : {:?}", self.target.debug_render(), self.ranges)
+    }
+}
+
+pub(crate) fn call_hierarchy(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    goto_definition::goto_definition(db, position)
+}
+
+pub(crate) fn incoming_calls(db: &RootDatabase, position: FilePosition) -> Option<Vec<CallItem>> {
+    let sema = Semantics::new(db);
+
+    // 1. Find all refs
+    // 2. Loop through refs and determine unique fndef. This will become our `from: CallHierarchyItem,` in the reply.
+    // 3. Add ranges relative to the start of the fndef.
+    let refs = references::find_all_refs(&sema, position, None)?;
+
+    let mut calls = CallLocations::default();
+
+    for reference in refs.info.references() {
+        let file_id = reference.file_range.file_id;
+        let file = sema.parse(file_id);
+        let file = file.syntax();
+        let token = file.token_at_offset(reference.file_range.range.start()).next()?;
+        let token = sema.descend_into_macros(token);
+        let syntax = token.parent();
+
+        // This target is the containing function
+        if let Some(nav) = syntax.ancestors().find_map(|node| {
+            match_ast! {
+                match node {
+                    ast::Fn(it) => {
+                        let def = sema.to_def(&it)?;
+                        Some(def.to_nav(sema.db))
+                    },
+                    _ => None,
+                }
+            }
+        }) {
+            let relative_range = reference.file_range.range;
+            calls.add(&nav, relative_range);
+        }
+    }
+
+    Some(calls.into_items())
+}
+
+pub(crate) fn outgoing_calls(db: &RootDatabase, position: FilePosition) -> Option<Vec<CallItem>> {
+    let sema = Semantics::new(db);
+    let file_id = position.file_id;
+    let file = sema.parse(file_id);
+    let file = file.syntax();
+    let token = file.token_at_offset(position.offset).next()?;
+    let token = sema.descend_into_macros(token);
+    let syntax = token.parent();
+
+    let mut calls = CallLocations::default();
+
+    syntax
+        .descendants()
+        .filter_map(|node| FnCallNode::with_node_exact(&node))
+        .filter_map(|call_node| {
+            let name_ref = call_node.name_ref()?;
+
+            if let Some(func_target) = match &call_node {
+                FnCallNode::CallExpr(expr) => {
+                    //FIXME: Type::as_callable is broken
+                    let callable = sema.type_of_expr(&expr.expr()?)?.as_callable(db)?;
+                    match callable.kind() {
+                        hir::CallableKind::Function(it) => {
+                            let fn_def: hir::Function = it.into();
+                            let nav = fn_def.to_nav(db);
+                            Some(nav)
+                        }
+                        _ => None,
+                    }
+                }
+                FnCallNode::MethodCallExpr(expr) => {
+                    let function = sema.resolve_method_call(&expr)?;
+                    Some(function.to_nav(db))
+                }
+            } {
+                Some((func_target, name_ref.syntax().text_range()))
+            } else {
+                None
+            }
+        })
+        .for_each(|(nav, range)| calls.add(&nav, range));
+
+    Some(calls.into_items())
+}
+
+#[derive(Default)]
+struct CallLocations {
+    funcs: IndexMap<NavigationTarget, Vec<TextRange>>,
+}
+
+impl CallLocations {
+    fn add(&mut self, target: &NavigationTarget, range: TextRange) {
+        self.funcs.entry(target.clone()).or_default().push(range);
+    }
+
+    fn into_items(self) -> Vec<CallItem> {
+        self.funcs.into_iter().map(|(target, ranges)| CallItem { target, ranges }).collect()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::FilePosition;
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check_hierarchy(
+        ra_fixture: &str,
+        expected: &str,
+        expected_incoming: &[&str],
+        expected_outgoing: &[&str],
+    ) {
+        let (analysis, pos) = analysis_and_position(ra_fixture);
+
+        let mut navs = analysis.call_hierarchy(pos).unwrap().unwrap().info;
+        assert_eq!(navs.len(), 1);
+        let nav = navs.pop().unwrap();
+        nav.assert_match(expected);
+
+        let item_pos =
+            FilePosition { file_id: nav.file_id, offset: nav.focus_or_full_range().start() };
+        let incoming_calls = analysis.incoming_calls(item_pos).unwrap().unwrap();
+        assert_eq!(incoming_calls.len(), expected_incoming.len());
+
+        for call in 0..incoming_calls.len() {
+            incoming_calls[call].assert_match(expected_incoming[call]);
+        }
+
+        let outgoing_calls = analysis.outgoing_calls(item_pos).unwrap().unwrap();
+        assert_eq!(outgoing_calls.len(), expected_outgoing.len());
+
+        for call in 0..outgoing_calls.len() {
+            outgoing_calls[call].assert_match(expected_outgoing[call]);
+        }
+    }
+
+    #[test]
+    fn test_call_hierarchy_on_ref() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn callee() {}
+fn caller() {
+    call<|>ee();
+}
+"#,
+            "callee FN FileId(1) 0..14 3..9",
+            &["caller FN FileId(1) 15..44 18..24 : [33..39]"],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_on_def() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn call<|>ee() {}
+fn caller() {
+    callee();
+}
+"#,
+            "callee FN FileId(1) 0..14 3..9",
+            &["caller FN FileId(1) 15..44 18..24 : [33..39]"],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_in_same_fn() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn callee() {}
+fn caller() {
+    call<|>ee();
+    callee();
+}
+"#,
+            "callee FN FileId(1) 0..14 3..9",
+            &["caller FN FileId(1) 15..58 18..24 : [33..39, 47..53]"],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_in_different_fn() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn callee() {}
+fn caller1() {
+    call<|>ee();
+}
+
+fn caller2() {
+    callee();
+}
+"#,
+            "callee FN FileId(1) 0..14 3..9",
+            &[
+                "caller1 FN FileId(1) 15..45 18..25 : [34..40]",
+                "caller2 FN FileId(1) 47..77 50..57 : [66..72]",
+            ],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_in_tests_mod() {
+        check_hierarchy(
+            r#"
+//- /lib.rs cfg:test
+fn callee() {}
+fn caller1() {
+    call<|>ee();
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_caller() {
+        callee();
+    }
+}
+"#,
+            "callee FN FileId(1) 0..14 3..9",
+            &[
+                "caller1 FN FileId(1) 15..45 18..25 : [34..40]",
+                "test_caller FN FileId(1) 95..149 110..121 : [134..140]",
+            ],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_in_different_files() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+mod foo;
+use foo::callee;
+
+fn caller() {
+    call<|>ee();
+}
+
+//- /foo/mod.rs
+pub fn callee() {}
+"#,
+            "callee FN FileId(2) 0..18 7..13",
+            &["caller FN FileId(1) 27..56 30..36 : [45..51]"],
+            &[],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_outgoing() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn callee() {}
+fn call<|>er() {
+    callee();
+    callee();
+}
+"#,
+            "caller FN FileId(1) 15..58 18..24",
+            &[],
+            &["callee FN FileId(1) 0..14 3..9 : [33..39, 47..53]"],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_outgoing_in_different_files() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+mod foo;
+use foo::callee;
+
+fn call<|>er() {
+    callee();
+}
+
+//- /foo/mod.rs
+pub fn callee() {}
+"#,
+            "caller FN FileId(1) 27..56 30..36",
+            &[],
+            &["callee FN FileId(2) 0..18 7..13 : [45..51]"],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_incoming_outgoing() {
+        check_hierarchy(
+            r#"
+//- /lib.rs
+fn caller1() {
+    call<|>er2();
+}
+
+fn caller2() {
+    caller3();
+}
+
+fn caller3() {
+
+}
+"#,
+            "caller2 FN FileId(1) 33..64 36..43",
+            &["caller1 FN FileId(1) 0..31 3..10 : [19..26]"],
+            &["caller3 FN FileId(1) 66..83 69..76 : [52..59]"],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_issue_5103() {
+        check_hierarchy(
+            r#"
+fn a() {
+    b()
+}
+
+fn b() {}
+
+fn main() {
+    a<|>()
+}
+"#,
+            "a FN FileId(1) 0..18 3..4",
+            &["main FN FileId(1) 31..52 34..38 : [47..48]"],
+            &["b FN FileId(1) 20..29 23..24 : [13..14]"],
+        );
+
+        check_hierarchy(
+            r#"
+fn a() {
+    b<|>()
+}
+
+fn b() {}
+
+fn main() {
+    a()
+}
+"#,
+            "b FN FileId(1) 20..29 23..24",
+            &["a FN FileId(1) 0..18 3..4 : [13..14]"],
+            &[],
+        );
+    }
+}
diff --git a/crates/ide/src/call_info.rs b/crates/ide/src/call_info.rs
new file mode 100644
index 000000000..86abd2d8c
--- /dev/null
+++ b/crates/ide/src/call_info.rs
@@ -0,0 +1,742 @@
+//! FIXME: write short doc here
+use either::Either;
+use hir::{Docs, HirDisplay, Semantics, Type};
+use ide_db::RootDatabase;
+use stdx::format_to;
+use syntax::{
+    ast::{self, ArgListOwner},
+    match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextSize,
+};
+use test_utils::mark;
+
+use crate::FilePosition;
+
+/// Contains information about a call site. Specifically the
+/// `FunctionSignature`and current parameter.
+#[derive(Debug)]
+pub struct CallInfo {
+    pub doc: Option<String>,
+    pub signature: String,
+    pub active_parameter: Option<usize>,
+    parameters: Vec<TextRange>,
+}
+
+impl CallInfo {
+    pub fn parameter_labels(&self) -> impl Iterator<Item = &str> + '_ {
+        self.parameters.iter().map(move |&it| &self.signature[it])
+    }
+    pub fn parameter_ranges(&self) -> &[TextRange] {
+        &self.parameters
+    }
+    fn push_param(&mut self, param: &str) {
+        if !self.signature.ends_with('(') {
+            self.signature.push_str(", ");
+        }
+        let start = TextSize::of(&self.signature);
+        self.signature.push_str(param);
+        let end = TextSize::of(&self.signature);
+        self.parameters.push(TextRange::new(start, end))
+    }
+}
+
+/// Computes parameter information for the given call expression.
+pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<CallInfo> {
+    let sema = Semantics::new(db);
+    let file = sema.parse(position.file_id);
+    let file = file.syntax();
+    let token = file.token_at_offset(position.offset).next()?;
+    let token = sema.descend_into_macros(token);
+
+    let (callable, active_parameter) = call_info_impl(&sema, token)?;
+
+    let mut res =
+        CallInfo { doc: None, signature: String::new(), parameters: vec![], active_parameter };
+
+    match callable.kind() {
+        hir::CallableKind::Function(func) => {
+            res.doc = func.docs(db).map(|it| it.as_str().to_string());
+            format_to!(res.signature, "fn {}", func.name(db));
+        }
+        hir::CallableKind::TupleStruct(strukt) => {
+            res.doc = strukt.docs(db).map(|it| it.as_str().to_string());
+            format_to!(res.signature, "struct {}", strukt.name(db));
+        }
+        hir::CallableKind::TupleEnumVariant(variant) => {
+            res.doc = variant.docs(db).map(|it| it.as_str().to_string());
+            format_to!(
+                res.signature,
+                "enum {}::{}",
+                variant.parent_enum(db).name(db),
+                variant.name(db)
+            );
+        }
+        hir::CallableKind::Closure => (),
+    }
+
+    res.signature.push('(');
+    {
+        if let Some(self_param) = callable.receiver_param(db) {
+            format_to!(res.signature, "{}", self_param)
+        }
+        let mut buf = String::new();
+        for (pat, ty) in callable.params(db) {
+            buf.clear();
+            if let Some(pat) = pat {
+                match pat {
+                    Either::Left(_self) => format_to!(buf, "self: "),
+                    Either::Right(pat) => format_to!(buf, "{}: ", pat),
+                }
+            }
+            format_to!(buf, "{}", ty.display(db));
+            res.push_param(&buf);
+        }
+    }
+    res.signature.push(')');
+
+    match callable.kind() {
+        hir::CallableKind::Function(_) | hir::CallableKind::Closure => {
+            let ret_type = callable.return_type();
+            if !ret_type.is_unit() {
+                format_to!(res.signature, " -> {}", ret_type.display(db));
+            }
+        }
+        hir::CallableKind::TupleStruct(_) | hir::CallableKind::TupleEnumVariant(_) => {}
+    }
+    Some(res)
+}
+
+fn call_info_impl(
+    sema: &Semantics<RootDatabase>,
+    token: SyntaxToken,
+) -> Option<(hir::Callable, Option<usize>)> {
+    // Find the calling expression and it's NameRef
+    let calling_node = FnCallNode::with_node(&token.parent())?;
+
+    let callable = match &calling_node {
+        FnCallNode::CallExpr(call) => sema.type_of_expr(&call.expr()?)?.as_callable(sema.db)?,
+        FnCallNode::MethodCallExpr(call) => sema.resolve_method_call_as_callable(call)?,
+    };
+    let active_param = if let Some(arg_list) = calling_node.arg_list() {
+        // Number of arguments specified at the call site
+        let num_args_at_callsite = arg_list.args().count();
+
+        let arg_list_range = arg_list.syntax().text_range();
+        if !arg_list_range.contains_inclusive(token.text_range().start()) {
+            mark::hit!(call_info_bad_offset);
+            return None;
+        }
+        let param = std::cmp::min(
+            num_args_at_callsite,
+            arg_list
+                .args()
+                .take_while(|arg| arg.syntax().text_range().end() <= token.text_range().start())
+                .count(),
+        );
+
+        Some(param)
+    } else {
+        None
+    };
+    Some((callable, active_param))
+}
+
+#[derive(Debug)]
+pub(crate) struct ActiveParameter {
+    pub(crate) ty: Type,
+    pub(crate) name: String,
+}
+
+impl ActiveParameter {
+    pub(crate) fn at(db: &RootDatabase, position: FilePosition) -> Option<Self> {
+        let sema = Semantics::new(db);
+        let file = sema.parse(position.file_id);
+        let file = file.syntax();
+        let token = file.token_at_offset(position.offset).next()?;
+        let token = sema.descend_into_macros(token);
+        Self::at_token(&sema, token)
+    }
+
+    pub(crate) fn at_token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Option<Self> {
+        let (signature, active_parameter) = call_info_impl(&sema, token)?;
+
+        let idx = active_parameter?;
+        let mut params = signature.params(sema.db);
+        if !(idx < params.len()) {
+            mark::hit!(too_many_arguments);
+            return None;
+        }
+        let (pat, ty) = params.swap_remove(idx);
+        let name = pat?.to_string();
+        Some(ActiveParameter { ty, name })
+    }
+}
+
+#[derive(Debug)]
+pub(crate) enum FnCallNode {
+    CallExpr(ast::CallExpr),
+    MethodCallExpr(ast::MethodCallExpr),
+}
+
+impl FnCallNode {
+    fn with_node(syntax: &SyntaxNode) -> Option<FnCallNode> {
+        syntax.ancestors().find_map(|node| {
+            match_ast! {
+                match node {
+                    ast::CallExpr(it) => Some(FnCallNode::CallExpr(it)),
+                    ast::MethodCallExpr(it) => {
+                        let arg_list = it.arg_list()?;
+                        if !arg_list.syntax().text_range().contains_range(syntax.text_range()) {
+                            return None;
+                        }
+                        Some(FnCallNode::MethodCallExpr(it))
+                    },
+                    _ => None,
+                }
+            }
+        })
+    }
+
+    pub(crate) fn with_node_exact(node: &SyntaxNode) -> Option<FnCallNode> {
+        match_ast! {
+            match node {
+                ast::CallExpr(it) => Some(FnCallNode::CallExpr(it)),
+                ast::MethodCallExpr(it) => Some(FnCallNode::MethodCallExpr(it)),
+                _ => None,
+            }
+        }
+    }
+
+    pub(crate) fn name_ref(&self) -> Option<ast::NameRef> {
+        match self {
+            FnCallNode::CallExpr(call_expr) => Some(match call_expr.expr()? {
+                ast::Expr::PathExpr(path_expr) => path_expr.path()?.segment()?.name_ref()?,
+                _ => return None,
+            }),
+
+            FnCallNode::MethodCallExpr(call_expr) => {
+                call_expr.syntax().children().filter_map(ast::NameRef::cast).next()
+            }
+        }
+    }
+
+    fn arg_list(&self) -> Option<ast::ArgList> {
+        match self {
+            FnCallNode::CallExpr(expr) => expr.arg_list(),
+            FnCallNode::MethodCallExpr(expr) => expr.arg_list(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let call_info = analysis.call_info(position).unwrap();
+        let actual = match call_info {
+            Some(call_info) => {
+                let docs = match &call_info.doc {
+                    None => "".to_string(),
+                    Some(docs) => format!("{}\n------\n", docs.as_str()),
+                };
+                let params = call_info
+                    .parameter_labels()
+                    .enumerate()
+                    .map(|(i, param)| {
+                        if Some(i) == call_info.active_parameter {
+                            format!("<{}>", param)
+                        } else {
+                            param.to_string()
+                        }
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                format!("{}{}\n({})\n", docs, call_info.signature, params)
+            }
+            None => String::new(),
+        };
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn test_fn_signature_two_args() {
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3<|>, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3,<|> ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3, <|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_two_args_empty() {
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_two_args_first_generics() {
+        check(
+            r#"
+fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
+    where T: Copy + Display, U: Debug
+{ x + y }
+
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo(x: i32, y: {unknown}) -> u32
+                (<x: i32>, y: {unknown})
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_no_params() {
+        check(
+            r#"
+fn foo<T>() -> T where T: Copy + Display {}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo() -> {unknown}
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_impl() {
+        check(
+            r#"
+struct F;
+impl F { pub fn new() { } }
+fn bar() {
+    let _ : F = F::new(<|>);
+}
+"#,
+            expect![[r#"
+                fn new()
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_self() {
+        check(
+            r#"
+struct S;
+impl S { pub fn do_it(&self) {} }
+
+fn bar() {
+    let s: S = S;
+    s.do_it(<|>);
+}
+"#,
+            expect![[r#"
+                fn do_it(&self)
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_with_arg() {
+        check(
+            r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S.foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(&self, x: i32)
+                (<x: i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_with_arg_as_assoc_fn() {
+        check(
+            r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S::foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(self: &S, x: i32)
+                (<self: &S>, x: i32)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_simple() {
+        check(
+            r#"
+/// test
+// non-doc-comment
+fn foo(j: u32) -> u32 {
+    j
+}
+
+fn bar() {
+    let _ = foo(<|>);
+}
+"#,
+            expect![[r#"
+                test
+                ------
+                fn foo(j: u32) -> u32
+                (<j: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs() {
+        check(
+            r#"
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```
+/// let five = 5;
+///
+/// assert_eq!(6, my_crate::add_one(5));
+/// ```
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+pub fn do() {
+    add_one(<|>
+}"#,
+            expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_impl() {
+        check(
+            r#"
+struct addr;
+impl addr {
+    /// Adds one to the number given.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let five = 5;
+    ///
+    /// assert_eq!(6, my_crate::add_one(5));
+    /// ```
+    pub fn add_one(x: i32) -> i32 {
+        x + 1
+    }
+}
+
+pub fn do_it() {
+    addr {};
+    addr::add_one(<|>);
+}
+"#,
+            expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_from_actix() {
+        check(
+            r#"
+struct WriteHandler<E>;
+
+impl<E> WriteHandler<E> {
+    /// Method is called when writer emits error.
+    ///
+    /// If this method returns `ErrorAction::Continue` writer processing
+    /// continues otherwise stream processing stops.
+    fn error(&mut self, err: E, ctx: &mut Self::Context) -> Running {
+        Running::Stop
+    }
+
+    /// Method is called when writer finishes.
+    ///
+    /// By default this method stops actor's `Context`.
+    fn finished(&mut self, ctx: &mut Self::Context) {
+        ctx.stop()
+    }
+}
+
+pub fn foo(mut r: WriteHandler<()>) {
+    r.finished(<|>);
+}
+"#,
+            expect![[r#"
+                Method is called when writer finishes.
+
+                By default this method stops actor's `Context`.
+                ------
+                fn finished(&mut self, ctx: &mut {unknown})
+                (<ctx: &mut {unknown}>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn call_info_bad_offset() {
+        mark::check!(call_info_bad_offset);
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo <|> (3, ); }
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_nested_method_in_lambda() {
+        check(
+            r#"
+struct Foo;
+impl Foo { fn bar(&self, _: u32) { } }
+
+fn bar(_: u32) { }
+
+fn main() {
+    let foo = Foo;
+    std::thread::spawn(move || foo.bar(<|>));
+}
+"#,
+            expect![[r#"
+                fn bar(&self, _: u32)
+                (<_: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_for_tuple_structs() {
+        check(
+            r#"
+/// A cool tuple struct
+struct S(u32, i32);
+fn main() {
+    let s = S(0, <|>);
+}
+"#,
+            expect![[r#"
+                A cool tuple struct
+                ------
+                struct S(u32, i32)
+                (u32, <i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn generic_struct() {
+        check(
+            r#"
+struct S<T>(T);
+fn main() {
+    let s = S(<|>);
+}
+"#,
+            expect![[r#"
+                struct S({unknown})
+                (<{unknown}>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_for_enum_variants() {
+        check(
+            r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::A(<|>);
+}
+"#,
+            expect![[r#"
+                A Variant
+                ------
+                enum E::A(i32)
+                (<i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn cant_call_struct_record() {
+        check(
+            r#"
+struct S { x: u32, y: i32 }
+fn main() {
+    let s = S(<|>);
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn cant_call_enum_record() {
+        check(
+            r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::C(<|>);
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn fn_signature_for_call_in_macro() {
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() { }
+id! {
+    fn bar() { foo(<|>); }
+}
+"#,
+            expect![[r#"
+                fn foo()
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn call_info_for_lambdas() {
+        check(
+            r#"
+struct S;
+fn foo(s: S) -> i32 { 92 }
+fn main() {
+    (|s| foo(s))(<|>)
+}
+        "#,
+            expect![[r#"
+                (S) -> i32
+                (<S>)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn call_info_for_fn_ptr() {
+        check(
+            r#"
+fn main(f: fn(i32, f64) -> char) {
+    f(0, <|>)
+}
+        "#,
+            expect![[r#"
+                (i32, f64) -> char
+                (i32, <f64>)
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion.rs b/crates/ide/src/completion.rs
new file mode 100644
index 000000000..7fb4d687e
--- /dev/null
+++ b/crates/ide/src/completion.rs
@@ -0,0 +1,206 @@
+mod completion_config;
+mod completion_item;
+mod completion_context;
+mod presentation;
+mod patterns;
+#[cfg(test)]
+mod test_utils;
+
+mod complete_attribute;
+mod complete_dot;
+mod complete_record;
+mod complete_pattern;
+mod complete_fn_param;
+mod complete_keyword;
+mod complete_snippet;
+mod complete_qualified_path;
+mod complete_unqualified_path;
+mod complete_postfix;
+mod complete_macro_in_item_position;
+mod complete_trait_impl;
+
+use ide_db::RootDatabase;
+
+use crate::{
+    completion::{
+        completion_context::CompletionContext,
+        completion_item::{CompletionKind, Completions},
+    },
+    FilePosition,
+};
+
+pub use crate::completion::{
+    completion_config::CompletionConfig,
+    completion_item::{CompletionItem, CompletionItemKind, CompletionScore, InsertTextFormat},
+};
+
+//FIXME: split the following feature into fine-grained features.
+
+// Feature: Magic Completions
+//
+// In addition to usual reference completion, rust-analyzer provides some ✨magic✨
+// completions as well:
+//
+// Keywords like `if`, `else` `while`, `loop` are completed with braces, and cursor
+// is placed at the appropriate position. Even though `if` is easy to type, you
+// still want to complete it, to get ` { }` for free! `return` is inserted with a
+// space or `;` depending on the return type of the function.
+//
+// When completing a function call, `()` are automatically inserted. If a function
+// takes arguments, the cursor is positioned inside the parenthesis.
+//
+// There are postfix completions, which can be triggered by typing something like
+// `foo().if`. The word after `.` determines postfix completion. Possible variants are:
+//
+// - `expr.if` -> `if expr {}` or `if let ... {}` for `Option` or `Result`
+// - `expr.match` -> `match expr {}`
+// - `expr.while` -> `while expr {}` or `while let ... {}` for `Option` or `Result`
+// - `expr.ref` -> `&expr`
+// - `expr.refm` -> `&mut expr`
+// - `expr.not` -> `!expr`
+// - `expr.dbg` -> `dbg!(expr)`
+//
+// There also snippet completions:
+//
+// .Expressions
+// - `pd` -> `eprintln!(" = {:?}", );`
+// - `ppd` -> `eprintln!(" = {:#?}", );`
+//
+// .Items
+// - `tfn` -> `#[test] fn feature(){}`
+// - `tmod` ->
+// ```rust
+// #[cfg(test)]
+// mod tests {
+//     use super::*;
+//
+//     #[test]
+//     fn test_name() {}
+// }
+// ```
+
+/// Main entry point for completion. We run completion as a two-phase process.
+///
+/// First, we look at the position and collect a so-called `CompletionContext.
+/// This is a somewhat messy process, because, during completion, syntax tree is
+/// incomplete and can look really weird.
+///
+/// Once the context is collected, we run a series of completion routines which
+/// look at the context and produce completion items. One subtlety about this
+/// phase is that completion engine should not filter by the substring which is
+/// already present, it should give all possible variants for the identifier at
+/// the caret. In other words, for
+///
+/// ```no-run
+/// fn f() {
+///     let foo = 92;
+///     let _ = bar<|>
+/// }
+/// ```
+///
+/// `foo` *should* be present among the completion variants. Filtering by
+/// identifier prefix/fuzzy match should be done higher in the stack, together
+/// with ordering of completions (currently this is done by the client).
+pub(crate) fn completions(
+    db: &RootDatabase,
+    config: &CompletionConfig,
+    position: FilePosition,
+) -> Option<Completions> {
+    let ctx = CompletionContext::new(db, position, config)?;
+
+    let mut acc = Completions::default();
+    complete_attribute::complete_attribute(&mut acc, &ctx);
+    complete_fn_param::complete_fn_param(&mut acc, &ctx);
+    complete_keyword::complete_expr_keyword(&mut acc, &ctx);
+    complete_keyword::complete_use_tree_keyword(&mut acc, &ctx);
+    complete_snippet::complete_expr_snippet(&mut acc, &ctx);
+    complete_snippet::complete_item_snippet(&mut acc, &ctx);
+    complete_qualified_path::complete_qualified_path(&mut acc, &ctx);
+    complete_unqualified_path::complete_unqualified_path(&mut acc, &ctx);
+    complete_dot::complete_dot(&mut acc, &ctx);
+    complete_record::complete_record(&mut acc, &ctx);
+    complete_pattern::complete_pattern(&mut acc, &ctx);
+    complete_postfix::complete_postfix(&mut acc, &ctx);
+    complete_macro_in_item_position::complete_macro_in_item_position(&mut acc, &ctx);
+    complete_trait_impl::complete_trait_impl(&mut acc, &ctx);
+
+    Some(acc)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::completion_config::CompletionConfig;
+    use crate::mock_analysis::analysis_and_position;
+
+    struct DetailAndDocumentation<'a> {
+        detail: &'a str,
+        documentation: &'a str,
+    }
+
+    fn check_detail_and_documentation(ra_fixture: &str, expected: DetailAndDocumentation) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let config = CompletionConfig::default();
+        let completions = analysis.completions(&config, position).unwrap().unwrap();
+        for item in completions {
+            if item.detail() == Some(expected.detail) {
+                let opt = item.documentation();
+                let doc = opt.as_ref().map(|it| it.as_str());
+                assert_eq!(doc, Some(expected.documentation));
+                return;
+            }
+        }
+        panic!("completion detail not found: {}", expected.detail)
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_attr() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        #[doc = "Do the foo"]
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: "Do the foo" },
+        );
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_comment() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        /// Do the foo
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: " Do the foo" },
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_attribute.rs b/crates/ide/src/completion/complete_attribute.rs
new file mode 100644
index 000000000..603d935de
--- /dev/null
+++ b/crates/ide/src/completion/complete_attribute.rs
@@ -0,0 +1,644 @@
+//! Completion for attributes
+//!
+//! This module uses a bit of static metadata to provide completions
+//! for built-in attributes.
+
+use rustc_hash::FxHashSet;
+use syntax::{ast, AstNode, SyntaxKind};
+
+use crate::completion::{
+    completion_context::CompletionContext,
+    completion_item::{CompletionItem, CompletionItemKind, CompletionKind, Completions},
+};
+
+pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
+    let attribute = ctx.attribute_under_caret.as_ref()?;
+    match (attribute.path(), attribute.token_tree()) {
+        (Some(path), Some(token_tree)) if path.to_string() == "derive" => {
+            complete_derive(acc, ctx, token_tree)
+        }
+        (Some(path), Some(token_tree))
+            if ["allow", "warn", "deny", "forbid"]
+                .iter()
+                .any(|lint_level| lint_level == &path.to_string()) =>
+        {
+            complete_lint(acc, ctx, token_tree)
+        }
+        (_, Some(_token_tree)) => {}
+        _ => complete_attribute_start(acc, ctx, attribute),
+    }
+    Some(())
+}
+
+fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attribute: &ast::Attr) {
+    for attr_completion in ATTRIBUTES {
+        let mut item = CompletionItem::new(
+            CompletionKind::Attribute,
+            ctx.source_range(),
+            attr_completion.label,
+        )
+        .kind(CompletionItemKind::Attribute);
+
+        if let Some(lookup) = attr_completion.lookup {
+            item = item.lookup_by(lookup);
+        }
+
+        match (attr_completion.snippet, ctx.config.snippet_cap) {
+            (Some(snippet), Some(cap)) => {
+                item = item.insert_snippet(cap, snippet);
+            }
+            _ => {}
+        }
+
+        if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
+            acc.add(item);
+        }
+    }
+}
+
+struct AttrCompletion {
+    label: &'static str,
+    lookup: Option<&'static str>,
+    snippet: Option<&'static str>,
+    prefer_inner: bool,
+}
+
+impl AttrCompletion {
+    const fn prefer_inner(self) -> AttrCompletion {
+        AttrCompletion { prefer_inner: true, ..self }
+    }
+}
+
+const fn attr(
+    label: &'static str,
+    lookup: Option<&'static str>,
+    snippet: Option<&'static str>,
+) -> AttrCompletion {
+    AttrCompletion { label, lookup, snippet, prefer_inner: false }
+}
+
+const ATTRIBUTES: &[AttrCompletion] = &[
+    attr("allow(…)", Some("allow"), Some("allow(${0:lint})")),
+    attr("cfg_attr(…)", Some("cfg_attr"), Some("cfg_attr(${1:predicate}, ${0:attr})")),
+    attr("cfg(…)", Some("cfg"), Some("cfg(${0:predicate})")),
+    attr("deny(…)", Some("deny"), Some("deny(${0:lint})")),
+    attr(r#"deprecated = "…""#, Some("deprecated"), Some(r#"deprecated = "${0:reason}""#)),
+    attr("derive(…)", Some("derive"), Some(r#"derive(${0:Debug})"#)),
+    attr(r#"doc = "…""#, Some("doc"), Some(r#"doc = "${0:docs}""#)),
+    attr("feature(…)", Some("feature"), Some("feature(${0:flag})")).prefer_inner(),
+    attr("forbid(…)", Some("forbid"), Some("forbid(${0:lint})")),
+    // FIXME: resolve through macro resolution?
+    attr("global_allocator", None, None).prefer_inner(),
+    attr(r#"ignore = "…""#, Some("ignore"), Some(r#"ignore = "${0:reason}""#)),
+    attr("inline(…)", Some("inline"), Some("inline(${0:lint})")),
+    attr(r#"link_name = "…""#, Some("link_name"), Some(r#"link_name = "${0:symbol_name}""#)),
+    attr("link", None, None),
+    attr("macro_export", None, None),
+    attr("macro_use", None, None),
+    attr(r#"must_use = "…""#, Some("must_use"), Some(r#"must_use = "${0:reason}""#)),
+    attr("no_mangle", None, None),
+    attr("no_std", None, None).prefer_inner(),
+    attr("non_exhaustive", None, None),
+    attr("panic_handler", None, None).prefer_inner(),
+    attr("path = \"…\"", Some("path"), Some("path =\"${0:path}\"")),
+    attr("proc_macro", None, None),
+    attr("proc_macro_attribute", None, None),
+    attr("proc_macro_derive(…)", Some("proc_macro_derive"), Some("proc_macro_derive(${0:Trait})")),
+    attr("recursion_limit = …", Some("recursion_limit"), Some("recursion_limit = ${0:128}"))
+        .prefer_inner(),
+    attr("repr(…)", Some("repr"), Some("repr(${0:C})")),
+    attr(
+        "should_panic(…)",
+        Some("should_panic"),
+        Some(r#"should_panic(expected = "${0:reason}")"#),
+    ),
+    attr(
+        r#"target_feature = "…""#,
+        Some("target_feature"),
+        Some("target_feature = \"${0:feature}\""),
+    ),
+    attr("test", None, None),
+    attr("used", None, None),
+    attr("warn(…)", Some("warn"), Some("warn(${0:lint})")),
+    attr(
+        r#"windows_subsystem = "…""#,
+        Some("windows_subsystem"),
+        Some(r#"windows_subsystem = "${0:subsystem}""#),
+    )
+    .prefer_inner(),
+];
+
+fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
+    if let Ok(existing_derives) = parse_comma_sep_input(derive_input) {
+        for derive_completion in DEFAULT_DERIVE_COMPLETIONS
+            .into_iter()
+            .filter(|completion| !existing_derives.contains(completion.label))
+        {
+            let mut label = derive_completion.label.to_owned();
+            for dependency in derive_completion
+                .dependencies
+                .into_iter()
+                .filter(|&&dependency| !existing_derives.contains(dependency))
+            {
+                label.push_str(", ");
+                label.push_str(dependency);
+            }
+            acc.add(
+                CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label)
+                    .kind(CompletionItemKind::Attribute),
+            );
+        }
+
+        for custom_derive_name in get_derive_names_in_scope(ctx).difference(&existing_derives) {
+            acc.add(
+                CompletionItem::new(
+                    CompletionKind::Attribute,
+                    ctx.source_range(),
+                    custom_derive_name,
+                )
+                .kind(CompletionItemKind::Attribute),
+            );
+        }
+    }
+}
+
+fn complete_lint(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
+    if let Ok(existing_lints) = parse_comma_sep_input(derive_input) {
+        for lint_completion in DEFAULT_LINT_COMPLETIONS
+            .into_iter()
+            .filter(|completion| !existing_lints.contains(completion.label))
+        {
+            acc.add(
+                CompletionItem::new(
+                    CompletionKind::Attribute,
+                    ctx.source_range(),
+                    lint_completion.label,
+                )
+                .kind(CompletionItemKind::Attribute)
+                .detail(lint_completion.description),
+            );
+        }
+    }
+}
+
+fn parse_comma_sep_input(derive_input: ast::TokenTree) -> Result<FxHashSet<String>, ()> {
+    match (derive_input.left_delimiter_token(), derive_input.right_delimiter_token()) {
+        (Some(left_paren), Some(right_paren))
+            if left_paren.kind() == SyntaxKind::L_PAREN
+                && right_paren.kind() == SyntaxKind::R_PAREN =>
+        {
+            let mut input_derives = FxHashSet::default();
+            let mut current_derive = String::new();
+            for token in derive_input
+                .syntax()
+                .children_with_tokens()
+                .filter_map(|token| token.into_token())
+                .skip_while(|token| token != &left_paren)
+                .skip(1)
+                .take_while(|token| token != &right_paren)
+            {
+                if SyntaxKind::COMMA == token.kind() {
+                    if !current_derive.is_empty() {
+                        input_derives.insert(current_derive);
+                        current_derive = String::new();
+                    }
+                } else {
+                    current_derive.push_str(token.to_string().trim());
+                }
+            }
+
+            if !current_derive.is_empty() {
+                input_derives.insert(current_derive);
+            }
+            Ok(input_derives)
+        }
+        _ => Err(()),
+    }
+}
+
+fn get_derive_names_in_scope(ctx: &CompletionContext) -> FxHashSet<String> {
+    let mut result = FxHashSet::default();
+    ctx.scope.process_all_names(&mut |name, scope_def| {
+        if let hir::ScopeDef::MacroDef(mac) = scope_def {
+            if mac.is_derive_macro() {
+                result.insert(name.to_string());
+            }
+        }
+    });
+    result
+}
+
+struct DeriveCompletion {
+    label: &'static str,
+    dependencies: &'static [&'static str],
+}
+
+/// Standard Rust derives and the information about their dependencies
+/// (the dependencies are needed so that the main derive don't break the compilation when added)
+#[rustfmt::skip]
+const DEFAULT_DERIVE_COMPLETIONS: &[DeriveCompletion] = &[
+    DeriveCompletion { label: "Clone", dependencies: &[] },
+    DeriveCompletion { label: "Copy", dependencies: &["Clone"] },
+    DeriveCompletion { label: "Debug", dependencies: &[] },
+    DeriveCompletion { label: "Default", dependencies: &[] },
+    DeriveCompletion { label: "Hash", dependencies: &[] },
+    DeriveCompletion { label: "PartialEq", dependencies: &[] },
+    DeriveCompletion { label: "Eq", dependencies: &["PartialEq"] },
+    DeriveCompletion { label: "PartialOrd", dependencies: &["PartialEq"] },
+    DeriveCompletion { label: "Ord", dependencies: &["PartialOrd", "Eq", "PartialEq"] },
+];
+
+struct LintCompletion {
+    label: &'static str,
+    description: &'static str,
+}
+
+#[rustfmt::skip]
+const DEFAULT_LINT_COMPLETIONS: &[LintCompletion] = &[
+    LintCompletion { label: "absolute_paths_not_starting_with_crate", description: r#"fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name"# },
+    LintCompletion { label: "anonymous_parameters", description: r#"detects anonymous parameters"# },
+    LintCompletion { label: "box_pointers", description: r#"use of owned (Box type) heap memory"# },
+    LintCompletion { label: "deprecated_in_future", description: r#"detects use of items that will be deprecated in a future version"# },
+    LintCompletion { label: "elided_lifetimes_in_paths", description: r#"hidden lifetime parameters in types are deprecated"# },
+    LintCompletion { label: "explicit_outlives_requirements", description: r#"outlives requirements can be inferred"# },
+    LintCompletion { label: "indirect_structural_match", description: r#"pattern with const indirectly referencing non-structural-match type"# },
+    LintCompletion { label: "keyword_idents", description: r#"detects edition keywords being used as an identifier"# },
+    LintCompletion { label: "macro_use_extern_crate", description: r#"the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system"# },
+    LintCompletion { label: "meta_variable_misuse", description: r#"possible meta-variable misuse at macro definition"# },
+    LintCompletion { label: "missing_copy_implementations", description: r#"detects potentially-forgotten implementations of `Copy`"# },
+    LintCompletion { label: "missing_crate_level_docs", description: r#"detects crates with no crate-level documentation"# },
+    LintCompletion { label: "missing_debug_implementations", description: r#"detects missing implementations of Debug"# },
+    LintCompletion { label: "missing_docs", description: r#"detects missing documentation for public members"# },
+    LintCompletion { label: "missing_doc_code_examples", description: r#"detects publicly-exported items without code samples in their documentation"# },
+    LintCompletion { label: "non_ascii_idents", description: r#"detects non-ASCII identifiers"# },
+    LintCompletion { label: "private_doc_tests", description: r#"detects code samples in docs of private items not documented by rustdoc"# },
+    LintCompletion { label: "single_use_lifetimes", description: r#"detects lifetime parameters that are only used once"# },
+    LintCompletion { label: "trivial_casts", description: r#"detects trivial casts which could be removed"# },
+    LintCompletion { label: "trivial_numeric_casts", description: r#"detects trivial casts of numeric types which could be removed"# },
+    LintCompletion { label: "unaligned_references", description: r#"detects unaligned references to fields of packed structs"# },
+    LintCompletion { label: "unreachable_pub", description: r#"`pub` items not reachable from crate root"# },
+    LintCompletion { label: "unsafe_code", description: r#"usage of `unsafe` code"# },
+    LintCompletion { label: "unsafe_op_in_unsafe_fn", description: r#"unsafe operations in unsafe functions without an explicit unsafe block are deprecated"# },
+    LintCompletion { label: "unstable_features", description: r#"enabling unstable features (deprecated. do not use)"# },
+    LintCompletion { label: "unused_crate_dependencies", description: r#"crate dependencies that are never used"# },
+    LintCompletion { label: "unused_extern_crates", description: r#"extern crates that are never used"# },
+    LintCompletion { label: "unused_import_braces", description: r#"unnecessary braces around an imported item"# },
+    LintCompletion { label: "unused_lifetimes", description: r#"detects lifetime parameters that are never used"# },
+    LintCompletion { label: "unused_qualifications", description: r#"detects unnecessarily qualified names"# },
+    LintCompletion { label: "unused_results", description: r#"unused result of an expression in a statement"# },
+    LintCompletion { label: "variant_size_differences", description: r#"detects enums with widely varying variant sizes"# },
+    LintCompletion { label: "array_into_iter", description: r#"detects calling `into_iter` on arrays"# },
+    LintCompletion { label: "asm_sub_register", description: r#"using only a subset of a register for inline asm inputs"# },
+    LintCompletion { label: "bare_trait_objects", description: r#"suggest using `dyn Trait` for trait objects"# },
+    LintCompletion { label: "bindings_with_variant_name", description: r#"detects pattern bindings with the same name as one of the matched variants"# },
+    LintCompletion { label: "cenum_impl_drop_cast", description: r#"a C-like enum implementing Drop is cast"# },
+    LintCompletion { label: "clashing_extern_declarations", description: r#"detects when an extern fn has been declared with the same name but different types"# },
+    LintCompletion { label: "coherence_leak_check", description: r#"distinct impls distinguished only by the leak-check code"# },
+    LintCompletion { label: "confusable_idents", description: r#"detects visually confusable pairs between identifiers"# },
+    LintCompletion { label: "dead_code", description: r#"detect unused, unexported items"# },
+    LintCompletion { label: "deprecated", description: r#"detects use of deprecated items"# },
+    LintCompletion { label: "ellipsis_inclusive_range_patterns", description: r#"`...` range patterns are deprecated"# },
+    LintCompletion { label: "exported_private_dependencies", description: r#"public interface leaks type from a private dependency"# },
+    LintCompletion { label: "illegal_floating_point_literal_pattern", description: r#"floating-point literals cannot be used in patterns"# },
+    LintCompletion { label: "improper_ctypes", description: r#"proper use of libc types in foreign modules"# },
+    LintCompletion { label: "improper_ctypes_definitions", description: r#"proper use of libc types in foreign item definitions"# },
+    LintCompletion { label: "incomplete_features", description: r#"incomplete features that may function improperly in some or all cases"# },
+    LintCompletion { label: "inline_no_sanitize", description: r#"detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`"# },
+    LintCompletion { label: "intra_doc_link_resolution_failure", description: r#"failures in resolving intra-doc link targets"# },
+    LintCompletion { label: "invalid_codeblock_attributes", description: r#"codeblock attribute looks a lot like a known one"# },
+    LintCompletion { label: "invalid_value", description: r#"an invalid value is being created (such as a NULL reference)"# },
+    LintCompletion { label: "irrefutable_let_patterns", description: r#"detects irrefutable patterns in if-let and while-let statements"# },
+    LintCompletion { label: "late_bound_lifetime_arguments", description: r#"detects generic lifetime arguments in path segments with late bound lifetime parameters"# },
+    LintCompletion { label: "mixed_script_confusables", description: r#"detects Unicode scripts whose mixed script confusables codepoints are solely used"# },
+    LintCompletion { label: "mutable_borrow_reservation_conflict", description: r#"reservation of a two-phased borrow conflicts with other shared borrows"# },
+    LintCompletion { label: "non_camel_case_types", description: r#"types, variants, traits and type parameters should have camel case names"# },
+    LintCompletion { label: "non_shorthand_field_patterns", description: r#"using `Struct { x: x }` instead of `Struct { x }` in a pattern"# },
+    LintCompletion { label: "non_snake_case", description: r#"variables, methods, functions, lifetime parameters and modules should have snake case names"# },
+    LintCompletion { label: "non_upper_case_globals", description: r#"static constants should have uppercase identifiers"# },
+    LintCompletion { label: "no_mangle_generic_items", description: r#"generic items must be mangled"# },
+    LintCompletion { label: "overlapping_patterns", description: r#"detects overlapping patterns"# },
+    LintCompletion { label: "path_statements", description: r#"path statements with no effect"# },
+    LintCompletion { label: "private_in_public", description: r#"detect private items in public interfaces not caught by the old implementation"# },
+    LintCompletion { label: "proc_macro_derive_resolution_fallback", description: r#"detects proc macro derives using inaccessible names from parent modules"# },
+    LintCompletion { label: "redundant_semicolons", description: r#"detects unnecessary trailing semicolons"# },
+    LintCompletion { label: "renamed_and_removed_lints", description: r#"lints that have been renamed or removed"# },
+    LintCompletion { label: "safe_packed_borrows", description: r#"safe borrows of fields of packed structs were erroneously allowed"# },
+    LintCompletion { label: "stable_features", description: r#"stable features found in `#[feature]` directive"# },
+    LintCompletion { label: "trivial_bounds", description: r#"these bounds don't depend on an type parameters"# },
+    LintCompletion { label: "type_alias_bounds", description: r#"bounds in type aliases are not enforced"# },
+    LintCompletion { label: "tyvar_behind_raw_pointer", description: r#"raw pointer to an inference variable"# },
+    LintCompletion { label: "uncommon_codepoints", description: r#"detects uncommon Unicode codepoints in identifiers"# },
+    LintCompletion { label: "unconditional_recursion", description: r#"functions that cannot return without calling themselves"# },
+    LintCompletion { label: "unknown_lints", description: r#"unrecognized lint attribute"# },
+    LintCompletion { label: "unnameable_test_items", description: r#"detects an item that cannot be named being marked as `#[test_case]`"# },
+    LintCompletion { label: "unreachable_code", description: r#"detects unreachable code paths"# },
+    LintCompletion { label: "unreachable_patterns", description: r#"detects unreachable patterns"# },
+    LintCompletion { label: "unstable_name_collisions", description: r#"detects name collision with an existing but unstable method"# },
+    LintCompletion { label: "unused_allocation", description: r#"detects unnecessary allocations that can be eliminated"# },
+    LintCompletion { label: "unused_assignments", description: r#"detect assignments that will never be read"# },
+    LintCompletion { label: "unused_attributes", description: r#"detects attributes that were not used by the compiler"# },
+    LintCompletion { label: "unused_braces", description: r#"unnecessary braces around an expression"# },
+    LintCompletion { label: "unused_comparisons", description: r#"comparisons made useless by limits of the types involved"# },
+    LintCompletion { label: "unused_doc_comments", description: r#"detects doc comments that aren't used by rustdoc"# },
+    LintCompletion { label: "unused_features", description: r#"unused features found in crate-level `#[feature]` directives"# },
+    LintCompletion { label: "unused_imports", description: r#"imports that are never used"# },
+    LintCompletion { label: "unused_labels", description: r#"detects labels that are never used"# },
+    LintCompletion { label: "unused_macros", description: r#"detects macros that were not used"# },
+    LintCompletion { label: "unused_must_use", description: r#"unused result of a type flagged as `#[must_use]`"# },
+    LintCompletion { label: "unused_mut", description: r#"detect mut variables which don't need to be mutable"# },
+    LintCompletion { label: "unused_parens", description: r#"`if`, `match`, `while` and `return` do not need parentheses"# },
+    LintCompletion { label: "unused_unsafe", description: r#"unnecessary use of an `unsafe` block"# },
+    LintCompletion { label: "unused_variables", description: r#"detect variables which are not used in any way"# },
+    LintCompletion { label: "warnings", description: r#"mass-change the level for lints which produce warnings"# },
+    LintCompletion { label: "where_clauses_object_safety", description: r#"checks the object safety of where clauses"# },
+    LintCompletion { label: "while_true", description: r#"suggest using `loop { }` instead of `while true { }`"# },
+    LintCompletion { label: "ambiguous_associated_items", description: r#"ambiguous associated items"# },
+    LintCompletion { label: "arithmetic_overflow", description: r#"arithmetic operation overflows"# },
+    LintCompletion { label: "conflicting_repr_hints", description: r#"conflicts between `#[repr(..)]` hints that were previously accepted and used in practice"# },
+    LintCompletion { label: "const_err", description: r#"constant evaluation detected erroneous expression"# },
+    LintCompletion { label: "ill_formed_attribute_input", description: r#"ill-formed attribute inputs that were previously accepted and used in practice"# },
+    LintCompletion { label: "incomplete_include", description: r#"trailing content in included file"# },
+    LintCompletion { label: "invalid_type_param_default", description: r#"type parameter default erroneously allowed in invalid location"# },
+    LintCompletion { label: "macro_expanded_macro_exports_accessed_by_absolute_paths", description: r#"macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths"# },
+    LintCompletion { label: "missing_fragment_specifier", description: r#"detects missing fragment specifiers in unused `macro_rules!` patterns"# },
+    LintCompletion { label: "mutable_transmutes", description: r#"mutating transmuted &mut T from &T may cause undefined behavior"# },
+    LintCompletion { label: "no_mangle_const_items", description: r#"const items will not have their symbols exported"# },
+    LintCompletion { label: "order_dependent_trait_objects", description: r#"trait-object types were treated as different depending on marker-trait order"# },
+    LintCompletion { label: "overflowing_literals", description: r#"literal out of range for its type"# },
+    LintCompletion { label: "patterns_in_fns_without_body", description: r#"patterns in functions without body were erroneously allowed"# },
+    LintCompletion { label: "pub_use_of_private_extern_crate", description: r#"detect public re-exports of private extern crates"# },
+    LintCompletion { label: "soft_unstable", description: r#"a feature gate that doesn't break dependent crates"# },
+    LintCompletion { label: "unconditional_panic", description: r#"operation will cause a panic at runtime"# },
+    LintCompletion { label: "unknown_crate_types", description: r#"unknown crate type found in `#[crate_type]` directive"# },
+];
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Attribute);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn empty_derive_completion() {
+        check(
+            r#"
+#[derive(<|>)]
+struct Test {}
+        "#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq, PartialEq
+                at Hash
+                at Ord, PartialOrd, Eq, PartialEq
+                at PartialEq
+                at PartialOrd, PartialEq
+            "#]],
+        );
+    }
+
+    #[test]
+    fn empty_lint_completion() {
+        check(
+            r#"#[allow(<|>)]"#,
+            expect![[r#"
+                at absolute_paths_not_starting_with_crate fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name
+                at ambiguous_associated_items ambiguous associated items
+                at anonymous_parameters detects anonymous parameters
+                at arithmetic_overflow arithmetic operation overflows
+                at array_into_iter  detects calling `into_iter` on arrays
+                at asm_sub_register using only a subset of a register for inline asm inputs
+                at bare_trait_objects suggest using `dyn Trait` for trait objects
+                at bindings_with_variant_name detects pattern bindings with the same name as one of the matched variants
+                at box_pointers     use of owned (Box type) heap memory
+                at cenum_impl_drop_cast a C-like enum implementing Drop is cast
+                at clashing_extern_declarations detects when an extern fn has been declared with the same name but different types
+                at coherence_leak_check distinct impls distinguished only by the leak-check code
+                at conflicting_repr_hints conflicts between `#[repr(..)]` hints that were previously accepted and used in practice
+                at confusable_idents detects visually confusable pairs between identifiers
+                at const_err        constant evaluation detected erroneous expression
+                at dead_code        detect unused, unexported items
+                at deprecated       detects use of deprecated items
+                at deprecated_in_future detects use of items that will be deprecated in a future version
+                at elided_lifetimes_in_paths hidden lifetime parameters in types are deprecated
+                at ellipsis_inclusive_range_patterns `...` range patterns are deprecated
+                at explicit_outlives_requirements outlives requirements can be inferred
+                at exported_private_dependencies public interface leaks type from a private dependency
+                at ill_formed_attribute_input ill-formed attribute inputs that were previously accepted and used in practice
+                at illegal_floating_point_literal_pattern floating-point literals cannot be used in patterns
+                at improper_ctypes  proper use of libc types in foreign modules
+                at improper_ctypes_definitions proper use of libc types in foreign item definitions
+                at incomplete_features incomplete features that may function improperly in some or all cases
+                at incomplete_include trailing content in included file
+                at indirect_structural_match pattern with const indirectly referencing non-structural-match type
+                at inline_no_sanitize detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`
+                at intra_doc_link_resolution_failure failures in resolving intra-doc link targets
+                at invalid_codeblock_attributes codeblock attribute looks a lot like a known one
+                at invalid_type_param_default type parameter default erroneously allowed in invalid location
+                at invalid_value    an invalid value is being created (such as a NULL reference)
+                at irrefutable_let_patterns detects irrefutable patterns in if-let and while-let statements
+                at keyword_idents   detects edition keywords being used as an identifier
+                at late_bound_lifetime_arguments detects generic lifetime arguments in path segments with late bound lifetime parameters
+                at macro_expanded_macro_exports_accessed_by_absolute_paths macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths
+                at macro_use_extern_crate the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system
+                at meta_variable_misuse possible meta-variable misuse at macro definition
+                at missing_copy_implementations detects potentially-forgotten implementations of `Copy`
+                at missing_crate_level_docs detects crates with no crate-level documentation
+                at missing_debug_implementations detects missing implementations of Debug
+                at missing_doc_code_examples detects publicly-exported items without code samples in their documentation
+                at missing_docs     detects missing documentation for public members
+                at missing_fragment_specifier detects missing fragment specifiers in unused `macro_rules!` patterns
+                at mixed_script_confusables detects Unicode scripts whose mixed script confusables codepoints are solely used
+                at mutable_borrow_reservation_conflict reservation of a two-phased borrow conflicts with other shared borrows
+                at mutable_transmutes mutating transmuted &mut T from &T may cause undefined behavior
+                at no_mangle_const_items const items will not have their symbols exported
+                at no_mangle_generic_items generic items must be mangled
+                at non_ascii_idents detects non-ASCII identifiers
+                at non_camel_case_types types, variants, traits and type parameters should have camel case names
+                at non_shorthand_field_patterns using `Struct { x: x }` instead of `Struct { x }` in a pattern
+                at non_snake_case   variables, methods, functions, lifetime parameters and modules should have snake case names
+                at non_upper_case_globals static constants should have uppercase identifiers
+                at order_dependent_trait_objects trait-object types were treated as different depending on marker-trait order
+                at overflowing_literals literal out of range for its type
+                at overlapping_patterns detects overlapping patterns
+                at path_statements  path statements with no effect
+                at patterns_in_fns_without_body patterns in functions without body were erroneously allowed
+                at private_doc_tests detects code samples in docs of private items not documented by rustdoc
+                at private_in_public detect private items in public interfaces not caught by the old implementation
+                at proc_macro_derive_resolution_fallback detects proc macro derives using inaccessible names from parent modules
+                at pub_use_of_private_extern_crate detect public re-exports of private extern crates
+                at redundant_semicolons detects unnecessary trailing semicolons
+                at renamed_and_removed_lints lints that have been renamed or removed
+                at safe_packed_borrows safe borrows of fields of packed structs were erroneously allowed
+                at single_use_lifetimes detects lifetime parameters that are only used once
+                at soft_unstable    a feature gate that doesn't break dependent crates
+                at stable_features  stable features found in `#[feature]` directive
+                at trivial_bounds   these bounds don't depend on an type parameters
+                at trivial_casts    detects trivial casts which could be removed
+                at trivial_numeric_casts detects trivial casts of numeric types which could be removed
+                at type_alias_bounds bounds in type aliases are not enforced
+                at tyvar_behind_raw_pointer raw pointer to an inference variable
+                at unaligned_references detects unaligned references to fields of packed structs
+                at uncommon_codepoints detects uncommon Unicode codepoints in identifiers
+                at unconditional_panic operation will cause a panic at runtime
+                at unconditional_recursion functions that cannot return without calling themselves
+                at unknown_crate_types unknown crate type found in `#[crate_type]` directive
+                at unknown_lints    unrecognized lint attribute
+                at unnameable_test_items detects an item that cannot be named being marked as `#[test_case]`
+                at unreachable_code detects unreachable code paths
+                at unreachable_patterns detects unreachable patterns
+                at unreachable_pub  `pub` items not reachable from crate root
+                at unsafe_code      usage of `unsafe` code
+                at unsafe_op_in_unsafe_fn unsafe operations in unsafe functions without an explicit unsafe block are deprecated
+                at unstable_features enabling unstable features (deprecated. do not use)
+                at unstable_name_collisions detects name collision with an existing but unstable method
+                at unused_allocation detects unnecessary allocations that can be eliminated
+                at unused_assignments detect assignments that will never be read
+                at unused_attributes detects attributes that were not used by the compiler
+                at unused_braces    unnecessary braces around an expression
+                at unused_comparisons comparisons made useless by limits of the types involved
+                at unused_crate_dependencies crate dependencies that are never used
+                at unused_doc_comments detects doc comments that aren't used by rustdoc
+                at unused_extern_crates extern crates that are never used
+                at unused_features  unused features found in crate-level `#[feature]` directives
+                at unused_import_braces unnecessary braces around an imported item
+                at unused_imports   imports that are never used
+                at unused_labels    detects labels that are never used
+                at unused_lifetimes detects lifetime parameters that are never used
+                at unused_macros    detects macros that were not used
+                at unused_must_use  unused result of a type flagged as `#[must_use]`
+                at unused_mut       detect mut variables which don't need to be mutable
+                at unused_parens    `if`, `match`, `while` and `return` do not need parentheses
+                at unused_qualifications detects unnecessarily qualified names
+                at unused_results   unused result of an expression in a statement
+                at unused_unsafe    unnecessary use of an `unsafe` block
+                at unused_variables detect variables which are not used in any way
+                at variant_size_differences detects enums with widely varying variant sizes
+                at warnings         mass-change the level for lints which produce warnings
+                at where_clauses_object_safety checks the object safety of where clauses
+                at while_true       suggest using `loop { }` instead of `while true { }`
+        "#]],
+        )
+    }
+
+    #[test]
+    fn no_completion_for_incorrect_derive() {
+        check(
+            r#"
+#[derive{<|>)]
+struct Test {}
+"#,
+            expect![[r#""#]],
+        )
+    }
+
+    #[test]
+    fn derive_with_input_completion() {
+        check(
+            r#"
+#[derive(serde::Serialize, PartialEq, <|>)]
+struct Test {}
+"#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq
+                at Hash
+                at Ord, PartialOrd, Eq
+                at PartialOrd
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_attribute_completion() {
+        check(
+            r#"#[<|>]"#,
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at forbid(…)
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at non_exhaustive
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_attribute_completion_inside_nested_attr() {
+        check(r#"#[cfg(<|>)]"#, expect![[]])
+    }
+
+    #[test]
+    fn test_inner_attribute_completion() {
+        check(
+            r"#![<|>]",
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at feature(…)
+                at forbid(…)
+                at global_allocator
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at no_std
+                at non_exhaustive
+                at panic_handler
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at recursion_limit = …
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+                at windows_subsystem = "…"
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_dot.rs b/crates/ide/src/completion/complete_dot.rs
new file mode 100644
index 000000000..532665285
--- /dev/null
+++ b/crates/ide/src/completion/complete_dot.rs
@@ -0,0 +1,416 @@
+//! Completes references after dot (fields and method calls).
+
+use hir::{HasVisibility, Type};
+use rustc_hash::FxHashSet;
+use test_utils::mark;
+
+use crate::completion::{completion_context::CompletionContext, completion_item::Completions};
+
+/// Complete dot accesses, i.e. fields or methods.
+pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
+    let dot_receiver = match &ctx.dot_receiver {
+        Some(expr) => expr,
+        _ => return,
+    };
+
+    let receiver_ty = match ctx.sema.type_of_expr(&dot_receiver) {
+        Some(ty) => ty,
+        _ => return,
+    };
+
+    if ctx.is_call {
+        mark::hit!(test_no_struct_field_completion_for_method_call);
+    } else {
+        complete_fields(acc, ctx, &receiver_ty);
+    }
+    complete_methods(acc, ctx, &receiver_ty);
+}
+
+fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
+    for receiver in receiver.autoderef(ctx.db) {
+        for (field, ty) in receiver.fields(ctx.db) {
+            if ctx.scope.module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
+                // Skip private field. FIXME: If the definition location of the
+                // field is editable, we should show the completion
+                continue;
+            }
+            acc.add_field(ctx, field, &ty);
+        }
+        for (i, ty) in receiver.tuple_fields(ctx.db).into_iter().enumerate() {
+            // FIXME: Handle visibility
+            acc.add_tuple_field(ctx, i, &ty);
+        }
+    }
+}
+
+fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
+    if let Some(krate) = ctx.krate {
+        let mut seen_methods = FxHashSet::default();
+        let traits_in_scope = ctx.scope.traits_in_scope();
+        receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
+            if func.has_self_param(ctx.db)
+                && ctx.scope.module().map_or(true, |m| func.is_visible_from(ctx.db, m))
+                && seen_methods.insert(func.name(ctx.db))
+            {
+                acc.add_function(ctx, func, None);
+            }
+            None::<()>
+        });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn test_struct_field_and_method_completion() {
+        check(
+            r#"
+struct S { foo: u32 }
+impl S {
+    fn bar(&self) {}
+}
+fn foo(s: S) { s.<|> }
+"#,
+            expect![[r#"
+                me bar() fn bar(&self)
+                fd foo   u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_struct_field_completion_self() {
+        check(
+            r#"
+struct S { the_field: (u32,) }
+impl S {
+    fn foo(self) { self.<|> }
+}
+"#,
+            expect![[r#"
+                me foo()     fn foo(self)
+                fd the_field (u32,)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_struct_field_completion_autoderef() {
+        check(
+            r#"
+struct A { the_field: (u32, i32) }
+impl A {
+    fn foo(&self) { self.<|> }
+}
+"#,
+            expect![[r#"
+                me foo()     fn foo(&self)
+                fd the_field (u32, i32)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_no_struct_field_completion_for_method_call() {
+        mark::check!(test_no_struct_field_completion_for_method_call);
+        check(
+            r#"
+struct A { the_field: u32 }
+fn foo(a: A) { a.<|>() }
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_visibility_filtering() {
+        check(
+            r#"
+mod inner {
+    pub struct A {
+        private_field: u32,
+        pub pub_field: u32,
+        pub(crate) crate_field: u32,
+        pub(super) super_field: u32,
+    }
+}
+fn foo(a: inner::A) { a.<|> }
+"#,
+            expect![[r#"
+                fd crate_field u32
+                fd pub_field   u32
+                fd super_field u32
+            "#]],
+        );
+
+        check(
+            r#"
+struct A {}
+mod m {
+    impl super::A {
+        fn private_method(&self) {}
+        pub(super) fn the_method(&self) {}
+    }
+}
+fn foo(a: A) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() pub(super) fn the_method(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_union_field_completion() {
+        check(
+            r#"
+union U { field: u8, other: u16 }
+fn foo(u: U) { u.<|> }
+"#,
+            expect![[r#"
+                fd field u8
+                fd other u16
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_method_completion_only_fitting_impls() {
+        check(
+            r#"
+struct A<T> {}
+impl A<u32> {
+    fn the_method(&self) {}
+}
+impl A<i32> {
+    fn the_other_method(&self) {}
+}
+fn foo(a: A<u32>) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_trait_method_completion() {
+        check(
+            r#"
+struct A {}
+trait Trait { fn the_method(&self); }
+impl Trait for A {}
+fn foo(a: A) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_trait_method_completion_deduplicated() {
+        check(
+            r"
+struct A {}
+trait Trait { fn the_method(&self); }
+impl<T> Trait for T {}
+fn foo(a: &A) { a.<|> }
+",
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_trait_method_from_other_module() {
+        check(
+            r"
+struct A {}
+mod m {
+    pub trait Trait { fn the_method(&self); }
+}
+use m::Trait;
+impl Trait for A {}
+fn foo(a: A) { a.<|> }
+",
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_no_non_self_method() {
+        check(
+            r#"
+struct A {}
+impl A {
+    fn the_method() {}
+}
+fn foo(a: A) {
+   a.<|>
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_tuple_field_completion() {
+        check(
+            r#"
+fn foo() {
+   let b = (0, 3.14);
+   b.<|>
+}
+"#,
+            expect![[r#"
+                fd 0 i32
+                fd 1 f64
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_tuple_field_inference() {
+        check(
+            r#"
+pub struct S;
+impl S { pub fn blah(&self) {} }
+
+struct T(S);
+
+impl T {
+    fn foo(&self) {
+        // FIXME: This doesn't work without the trailing `a` as `0.` is a float
+        self.0.a<|>
+    }
+}
+"#,
+            expect![[r#"
+                me blah() pub fn blah(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_completion_works_in_consts() {
+        check(
+            r#"
+struct A { the_field: u32 }
+const X: u32 = {
+    A { the_field: 92 }.<|>
+};
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_in_simple_macro_1() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(a.x<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_in_simple_macro_2() {
+        // this doesn't work yet because the macro doesn't expand without the token -- maybe it can be fixed with better recovery
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(a.<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_in_simple_macro_recursive_1() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(m!(m!(a.x<|>)))
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn macro_expansion_resilient() {
+        check(
+            r#"
+macro_rules! dbg {
+    () => {};
+    ($val:expr) => {
+        match $val { tmp => { tmp } }
+    };
+    // Trailing comma with single argument is ignored
+    ($val:expr,) => { $crate::dbg!($val) };
+    ($($val:expr),+ $(,)?) => {
+        ($($crate::dbg!($val)),+,)
+    };
+}
+struct A { the_field: u32 }
+fn foo(a: A) {
+    dbg!(a.<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_method_completion_issue_3547() {
+        check(
+            r#"
+struct HashSet<T> {}
+impl<T> HashSet<T> {
+    pub fn the_method(&self) {}
+}
+fn foo() {
+    let s: HashSet<_>;
+    s.<|>
+}
+"#,
+            expect![[r#"
+                me the_method() pub fn the_method(&self)
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_fn_param.rs b/crates/ide/src/completion/complete_fn_param.rs
new file mode 100644
index 000000000..7c63ce58f
--- /dev/null
+++ b/crates/ide/src/completion/complete_fn_param.rs
@@ -0,0 +1,135 @@
+//! See `complete_fn_param`.
+
+use rustc_hash::FxHashMap;
+use syntax::{
+    ast::{self, ModuleItemOwner},
+    match_ast, AstNode,
+};
+
+use crate::completion::{CompletionContext, CompletionItem, CompletionKind, Completions};
+
+/// Complete repeated parameters, both name and type. For example, if all
+/// functions in a file have a `spam: &mut Spam` parameter, a completion with
+/// `spam: &mut Spam` insert text/label and `spam` lookup string will be
+/// suggested.
+pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.is_param {
+        return;
+    }
+
+    let mut params = FxHashMap::default();
+
+    let me = ctx.token.ancestors().find_map(ast::Fn::cast);
+    let mut process_fn = |func: ast::Fn| {
+        if Some(&func) == me.as_ref() {
+            return;
+        }
+        func.param_list().into_iter().flat_map(|it| it.params()).for_each(|param| {
+            let text = param.syntax().text().to_string();
+            params.entry(text).or_insert(param);
+        })
+    };
+
+    for node in ctx.token.parent().ancestors() {
+        match_ast! {
+            match node {
+                ast::SourceFile(it) => it.items().filter_map(|item| match item {
+                    ast::Item::Fn(it) => Some(it),
+                    _ => None,
+                }).for_each(&mut process_fn),
+                ast::ItemList(it) => it.items().filter_map(|item| match item {
+                    ast::Item::Fn(it) => Some(it),
+                    _ => None,
+                }).for_each(&mut process_fn),
+                ast::AssocItemList(it) => it.assoc_items().filter_map(|item| match item {
+                    ast::AssocItem::Fn(it) => Some(it),
+                    _ => None,
+                }).for_each(&mut process_fn),
+                _ => continue,
+            }
+        };
+    }
+
+    params
+        .into_iter()
+        .filter_map(|(label, param)| {
+            let lookup = param.pat()?.syntax().text().to_string();
+            Some((label, lookup))
+        })
+        .for_each(|(label, lookup)| {
+            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
+                .kind(crate::CompletionItemKind::Binding)
+                .lookup_by(lookup)
+                .add_to(acc)
+        });
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Magic);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn test_param_completion_last_param() {
+        check(
+            r#"
+fn foo(file_id: FileId) {}
+fn bar(file_id: FileId) {}
+fn baz(file<|>) {}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_param_completion_nth_param() {
+        check(
+            r#"
+fn foo(file_id: FileId) {}
+fn baz(file<|>, x: i32) {}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_param_completion_trait_param() {
+        check(
+            r#"
+pub(crate) trait SourceRoot {
+    pub fn contains(&self, file_id: FileId) -> bool;
+    pub fn module_map(&self) -> &ModuleMap;
+    pub fn lines(&self, file_id: FileId) -> &LineIndex;
+    pub fn syntax(&self, file<|>)
+}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_param_in_inner_function() {
+        check(
+            r#"
+fn outer(text: String) {
+    fn inner(<|>)
+}
+"#,
+            expect![[r#"
+                bn text: String
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion/complete_keyword.rs b/crates/ide/src/completion/complete_keyword.rs
new file mode 100644
index 000000000..a80708935
--- /dev/null
+++ b/crates/ide/src/completion/complete_keyword.rs
@@ -0,0 +1,536 @@
+//! FIXME: write short doc here
+
+use syntax::{ast, SyntaxKind};
+use test_utils::mark;
+
+use crate::completion::{
+    CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
+};
+
+pub(super) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionContext) {
+    // complete keyword "crate" in use stmt
+    let source_range = ctx.source_range();
+    match (ctx.use_item_syntax.as_ref(), ctx.path_prefix.as_ref()) {
+        (Some(_), None) => {
+            CompletionItem::new(CompletionKind::Keyword, source_range, "crate::")
+                .kind(CompletionItemKind::Keyword)
+                .insert_text("crate::")
+                .add_to(acc);
+            CompletionItem::new(CompletionKind::Keyword, source_range, "self")
+                .kind(CompletionItemKind::Keyword)
+                .add_to(acc);
+            CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
+                .kind(CompletionItemKind::Keyword)
+                .insert_text("super::")
+                .add_to(acc);
+        }
+        (Some(_), Some(_)) => {
+            CompletionItem::new(CompletionKind::Keyword, source_range, "self")
+                .kind(CompletionItemKind::Keyword)
+                .add_to(acc);
+            CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
+                .kind(CompletionItemKind::Keyword)
+                .insert_text("super::")
+                .add_to(acc);
+        }
+        _ => {}
+    }
+
+    // Suggest .await syntax for types that implement Future trait
+    if let Some(receiver) = &ctx.dot_receiver {
+        if let Some(ty) = ctx.sema.type_of_expr(receiver) {
+            if ty.impls_future(ctx.db) {
+                CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
+                    .kind(CompletionItemKind::Keyword)
+                    .detail("expr.await")
+                    .insert_text("await")
+                    .add_to(acc);
+            }
+        };
+    }
+}
+
+pub(super) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionContext) {
+    if ctx.token.kind() == SyntaxKind::COMMENT {
+        mark::hit!(no_keyword_completion_in_comments);
+        return;
+    }
+
+    let has_trait_or_impl_parent = ctx.has_impl_parent || ctx.has_trait_parent;
+    if ctx.trait_as_prev_sibling || ctx.impl_as_prev_sibling {
+        add_keyword(ctx, acc, "where", "where ");
+        return;
+    }
+    if ctx.unsafe_is_prev {
+        if ctx.has_item_list_or_source_file_parent || ctx.block_expr_parent {
+            add_keyword(ctx, acc, "fn", "fn $0() {}")
+        }
+
+        if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
+            add_keyword(ctx, acc, "trait", "trait $0 {}");
+            add_keyword(ctx, acc, "impl", "impl $0 {}");
+        }
+
+        return;
+    }
+    if ctx.has_item_list_or_source_file_parent || has_trait_or_impl_parent || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "fn", "fn $0() {}");
+    }
+    if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "use", "use ");
+        add_keyword(ctx, acc, "impl", "impl $0 {}");
+        add_keyword(ctx, acc, "trait", "trait $0 {}");
+    }
+
+    if ctx.has_item_list_or_source_file_parent {
+        add_keyword(ctx, acc, "enum", "enum $0 {}");
+        add_keyword(ctx, acc, "struct", "struct $0");
+        add_keyword(ctx, acc, "union", "union $0 {}");
+    }
+
+    if ctx.is_expr {
+        add_keyword(ctx, acc, "match", "match $0 {}");
+        add_keyword(ctx, acc, "while", "while $0 {}");
+        add_keyword(ctx, acc, "loop", "loop {$0}");
+        add_keyword(ctx, acc, "if", "if ");
+        add_keyword(ctx, acc, "if let", "if let ");
+    }
+
+    if ctx.if_is_prev || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "let", "let ");
+    }
+
+    if ctx.after_if {
+        add_keyword(ctx, acc, "else", "else {$0}");
+        add_keyword(ctx, acc, "else if", "else if $0 {}");
+    }
+    if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "mod", "mod $0 {}");
+    }
+    if ctx.bind_pat_parent || ctx.ref_pat_parent {
+        add_keyword(ctx, acc, "mut", "mut ");
+    }
+    if ctx.has_item_list_or_source_file_parent || has_trait_or_impl_parent || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "const", "const ");
+        add_keyword(ctx, acc, "type", "type ");
+    }
+    if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "static", "static ");
+    };
+    if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "extern", "extern ");
+    }
+    if ctx.has_item_list_or_source_file_parent
+        || has_trait_or_impl_parent
+        || ctx.block_expr_parent
+        || ctx.is_match_arm
+    {
+        add_keyword(ctx, acc, "unsafe", "unsafe ");
+    }
+    if ctx.in_loop_body {
+        if ctx.can_be_stmt {
+            add_keyword(ctx, acc, "continue", "continue;");
+            add_keyword(ctx, acc, "break", "break;");
+        } else {
+            add_keyword(ctx, acc, "continue", "continue");
+            add_keyword(ctx, acc, "break", "break");
+        }
+    }
+    if ctx.has_item_list_or_source_file_parent || ctx.has_impl_parent {
+        add_keyword(ctx, acc, "pub", "pub ")
+    }
+
+    if !ctx.is_trivial_path {
+        return;
+    }
+    let fn_def = match &ctx.function_syntax {
+        Some(it) => it,
+        None => return,
+    };
+    acc.add_all(complete_return(ctx, &fn_def, ctx.can_be_stmt));
+}
+
+fn keyword(ctx: &CompletionContext, kw: &str, snippet: &str) -> CompletionItem {
+    let res = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw)
+        .kind(CompletionItemKind::Keyword);
+
+    match ctx.config.snippet_cap {
+        Some(cap) => res.insert_snippet(cap, snippet),
+        _ => res.insert_text(if snippet.contains('$') { kw } else { snippet }),
+    }
+    .build()
+}
+
+fn add_keyword(ctx: &CompletionContext, acc: &mut Completions, kw: &str, snippet: &str) {
+    acc.add(keyword(ctx, kw, snippet));
+}
+
+fn complete_return(
+    ctx: &CompletionContext,
+    fn_def: &ast::Fn,
+    can_be_stmt: bool,
+) -> Option<CompletionItem> {
+    let snip = match (can_be_stmt, fn_def.ret_type().is_some()) {
+        (true, true) => "return $0;",
+        (true, false) => "return;",
+        (false, true) => "return $0",
+        (false, false) => "return",
+    };
+    Some(keyword(ctx, "return", snip))
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+    use test_utils::mark;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Keyword);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn test_keywords_in_use_stmt() {
+        check(
+            r"use <|>",
+            expect![[r#"
+                kw crate::
+                kw self
+                kw super::
+            "#]],
+        );
+
+        check(
+            r"use a::<|>",
+            expect![[r#"
+                kw self
+                kw super::
+            "#]],
+        );
+
+        check(
+            r"use a::{b, <|>}",
+            expect![[r#"
+                kw self
+                kw super::
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_at_source_file_level() {
+        check(
+            r"m<|>",
+            expect![[r#"
+                kw const
+                kw enum
+                kw extern
+                kw fn
+                kw impl
+                kw mod
+                kw pub
+                kw static
+                kw struct
+                kw trait
+                kw type
+                kw union
+                kw unsafe
+                kw use
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_in_function() {
+        check(
+            r"fn quux() { <|> }",
+            expect![[r#"
+                kw const
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_inside_block() {
+        check(
+            r"fn quux() { if true { <|> } }",
+            expect![[r#"
+                kw const
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_after_if() {
+        check(
+            r#"fn quux() { if true { () } <|> }"#,
+            expect![[r#"
+                kw const
+                kw else
+                kw else if
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
+        );
+        check_edit(
+            "else",
+            r#"fn quux() { if true { () } <|> }"#,
+            r#"fn quux() { if true { () } else {$0} }"#,
+        );
+    }
+
+    #[test]
+    fn test_keywords_in_match_arm() {
+        check(
+            r#"
+fn quux() -> i32 {
+    match () { () => <|> }
+}
+"#,
+            expect![[r#"
+                kw if
+                kw if let
+                kw loop
+                kw match
+                kw return
+                kw unsafe
+                kw while
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_in_trait_def() {
+        check(
+            r"trait My { <|> }",
+            expect![[r#"
+                kw const
+                kw fn
+                kw type
+                kw unsafe
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_in_impl_def() {
+        check(
+            r"impl My { <|> }",
+            expect![[r#"
+                kw const
+                kw fn
+                kw pub
+                kw type
+                kw unsafe
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_in_loop() {
+        check(
+            r"fn my() { loop { <|> } }",
+            expect![[r#"
+                kw break
+                kw const
+                kw continue
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_after_unsafe_in_item_list() {
+        check(
+            r"unsafe <|>",
+            expect![[r#"
+                kw fn
+                kw impl
+                kw trait
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_keywords_after_unsafe_in_block_expr() {
+        check(
+            r"fn my_fn() { unsafe <|> }",
+            expect![[r#"
+                kw fn
+                kw impl
+                kw trait
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_mut_in_ref_and_in_fn_parameters_list() {
+        check(
+            r"fn my_fn(&<|>) {}",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+        check(
+            r"fn my_fn(<|>) {}",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+        check(
+            r"fn my_fn() { let &<|> }",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_where_keyword() {
+        check(
+            r"trait A <|>",
+            expect![[r#"
+                kw where
+            "#]],
+        );
+        check(
+            r"impl A <|>",
+            expect![[r#"
+                kw where
+            "#]],
+        );
+    }
+
+    #[test]
+    fn no_keyword_completion_in_comments() {
+        mark::check!(no_keyword_completion_in_comments);
+        check(
+            r#"
+fn test() {
+    let x = 2; // A comment<|>
+}
+"#,
+            expect![[""]],
+        );
+        check(
+            r#"
+/*
+Some multi-line comment<|>
+*/
+"#,
+            expect![[""]],
+        );
+        check(
+            r#"
+/// Some doc comment
+/// let test<|> = 1
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_completion_await_impls_future() {
+        check(
+            r#"
+//- /main.rs
+use std::future::*;
+struct A {}
+impl Future for A {}
+fn foo(a: A) { a.<|> }
+
+//- /std/lib.rs
+pub mod future {
+    #[lang = "future_trait"]
+    pub trait Future {}
+}
+"#,
+            expect![[r#"
+                kw await expr.await
+            "#]],
+        )
+    }
+
+    #[test]
+    fn after_let() {
+        check(
+            r#"fn main() { let _ = <|> }"#,
+            expect![[r#"
+                kw if
+                kw if let
+                kw loop
+                kw match
+                kw return
+                kw while
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion/complete_macro_in_item_position.rs b/crates/ide/src/completion/complete_macro_in_item_position.rs
new file mode 100644
index 000000000..0447f0511
--- /dev/null
+++ b/crates/ide/src/completion/complete_macro_in_item_position.rs
@@ -0,0 +1,41 @@
+//! FIXME: write short doc here
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &CompletionContext) {
+    // Show only macros in top level.
+    if ctx.is_new_item {
+        ctx.scope.process_all_names(&mut |name, res| {
+            if let hir::ScopeDef::MacroDef(mac) = res {
+                acc.add_macro(ctx, Some(name.to_string()), mac);
+            }
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn completes_macros_as_item() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn foo() {}
+
+<|>
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion/complete_pattern.rs b/crates/ide/src/completion/complete_pattern.rs
new file mode 100644
index 000000000..aceb77cb5
--- /dev/null
+++ b/crates/ide/src/completion/complete_pattern.rs
@@ -0,0 +1,88 @@
+//! FIXME: write short doc here
+
+use crate::completion::{CompletionContext, Completions};
+
+/// Completes constats and paths in patterns.
+pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.is_pat_binding_or_const {
+        return;
+    }
+    if ctx.record_pat_syntax.is_some() {
+        return;
+    }
+
+    // FIXME: ideally, we should look at the type we are matching against and
+    // suggest variants + auto-imports
+    ctx.scope.process_all_names(&mut |name, res| {
+        match &res {
+            hir::ScopeDef::ModuleDef(def) => match def {
+                hir::ModuleDef::Adt(hir::Adt::Enum(..))
+                | hir::ModuleDef::Adt(hir::Adt::Struct(..))
+                | hir::ModuleDef::EnumVariant(..)
+                | hir::ModuleDef::Const(..)
+                | hir::ModuleDef::Module(..) => (),
+                _ => return,
+            },
+            hir::ScopeDef::MacroDef(_) => (),
+            _ => return,
+        };
+
+        acc.add_resolution(ctx, name.to_string(), &res)
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn completes_enum_variants_and_modules() {
+        check(
+            r#"
+enum E { X }
+use self::E::X;
+const Z: E = E::X;
+mod m {}
+
+static FOO: E = E::X;
+struct Bar { f: u32 }
+
+fn foo() {
+   match E::X { <|> }
+}
+"#,
+            expect![[r#"
+                st Bar
+                en E
+                ev X   ()
+                ct Z
+                md m
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_in_simple_macro_call() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+enum E { X }
+
+fn foo() {
+   m!(match E::X { <|> })
+}
+"#,
+            expect![[r#"
+                en E
+                ma m!(…) macro_rules! m
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_postfix.rs b/crates/ide/src/completion/complete_postfix.rs
new file mode 100644
index 000000000..d50b13c52
--- /dev/null
+++ b/crates/ide/src/completion/complete_postfix.rs
@@ -0,0 +1,378 @@
+//! FIXME: write short doc here
+use assists::utils::TryEnum;
+use syntax::{
+    ast::{self, AstNode},
+    TextRange, TextSize,
+};
+use text_edit::TextEdit;
+
+use crate::{
+    completion::{
+        completion_config::SnippetCap,
+        completion_context::CompletionContext,
+        completion_item::{Builder, CompletionKind, Completions},
+    },
+    CompletionItem, CompletionItemKind,
+};
+
+pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.config.enable_postfix_completions {
+        return;
+    }
+
+    let dot_receiver = match &ctx.dot_receiver {
+        Some(it) => it,
+        None => return,
+    };
+
+    let receiver_text =
+        get_receiver_text(dot_receiver, ctx.dot_receiver_is_ambiguous_float_literal);
+
+    let receiver_ty = match ctx.sema.type_of_expr(&dot_receiver) {
+        Some(it) => it,
+        None => return,
+    };
+
+    let cap = match ctx.config.snippet_cap {
+        Some(it) => it,
+        None => return,
+    };
+    let try_enum = TryEnum::from_ty(&ctx.sema, &receiver_ty);
+    if let Some(try_enum) = &try_enum {
+        match try_enum {
+            TryEnum::Result => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "ifl",
+                    "if let Ok {}",
+                    &format!("if let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "while",
+                    "while let Ok {}",
+                    &format!("while let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+            }
+            TryEnum::Option => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "ifl",
+                    "if let Some {}",
+                    &format!("if let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "while",
+                    "while let Some {}",
+                    &format!("while let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                )
+                .add_to(acc);
+            }
+        }
+    } else if receiver_ty.is_bool() || receiver_ty.is_unknown() {
+        postfix_snippet(
+            ctx,
+            cap,
+            &dot_receiver,
+            "if",
+            "if expr {}",
+            &format!("if {} {{\n    $0\n}}", receiver_text),
+        )
+        .add_to(acc);
+        postfix_snippet(
+            ctx,
+            cap,
+            &dot_receiver,
+            "while",
+            "while expr {}",
+            &format!("while {} {{\n    $0\n}}", receiver_text),
+        )
+        .add_to(acc);
+        postfix_snippet(ctx, cap, &dot_receiver, "not", "!expr", &format!("!{}", receiver_text))
+            .add_to(acc);
+    }
+
+    postfix_snippet(ctx, cap, &dot_receiver, "ref", "&expr", &format!("&{}", receiver_text))
+        .add_to(acc);
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
+        "refm",
+        "&mut expr",
+        &format!("&mut {}", receiver_text),
+    )
+    .add_to(acc);
+
+    // The rest of the postfix completions create an expression that moves an argument,
+    // so it's better to consider references now to avoid breaking the compilation
+    let dot_receiver = include_references(dot_receiver);
+    let receiver_text =
+        get_receiver_text(&dot_receiver, ctx.dot_receiver_is_ambiguous_float_literal);
+
+    match try_enum {
+        Some(try_enum) => match try_enum {
+            TryEnum::Result => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "match",
+                    "match expr {}",
+                    &format!("match {} {{\n    Ok(${{1:_}}) => {{$2}},\n    Err(${{3:_}}) => {{$0}},\n}}", receiver_text),
+                )
+                .add_to(acc);
+            }
+            TryEnum::Option => {
+                postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "match",
+                    "match expr {}",
+                    &format!(
+                        "match {} {{\n    Some(${{1:_}}) => {{$2}},\n    None => {{$0}},\n}}",
+                        receiver_text
+                    ),
+                )
+                .add_to(acc);
+            }
+        },
+        None => {
+            postfix_snippet(
+                ctx,
+                cap,
+                &dot_receiver,
+                "match",
+                "match expr {}",
+                &format!("match {} {{\n    ${{1:_}} => {{$0}},\n}}", receiver_text),
+            )
+            .add_to(acc);
+        }
+    }
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
+        "box",
+        "Box::new(expr)",
+        &format!("Box::new({})", receiver_text),
+    )
+    .add_to(acc);
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
+        "dbg",
+        "dbg!(expr)",
+        &format!("dbg!({})", receiver_text),
+    )
+    .add_to(acc);
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
+        "call",
+        "function(expr)",
+        &format!("${{1}}({})", receiver_text),
+    )
+    .add_to(acc);
+}
+
+fn get_receiver_text(receiver: &ast::Expr, receiver_is_ambiguous_float_literal: bool) -> String {
+    if receiver_is_ambiguous_float_literal {
+        let text = receiver.syntax().text();
+        let without_dot = ..text.len() - TextSize::of('.');
+        text.slice(without_dot).to_string()
+    } else {
+        receiver.to_string()
+    }
+}
+
+fn include_references(initial_element: &ast::Expr) -> ast::Expr {
+    let mut resulting_element = initial_element.clone();
+    while let Some(parent_ref_element) =
+        resulting_element.syntax().parent().and_then(ast::RefExpr::cast)
+    {
+        resulting_element = ast::Expr::from(parent_ref_element);
+    }
+    resulting_element
+}
+
+fn postfix_snippet(
+    ctx: &CompletionContext,
+    cap: SnippetCap,
+    receiver: &ast::Expr,
+    label: &str,
+    detail: &str,
+    snippet: &str,
+) -> Builder {
+    let edit = {
+        let receiver_syntax = receiver.syntax();
+        let receiver_range = ctx.sema.original_range(receiver_syntax).range;
+        let delete_range = TextRange::new(receiver_range.start(), ctx.source_range().end());
+        TextEdit::replace(delete_range, snippet.to_string())
+    };
+    CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label)
+        .detail(detail)
+        .kind(CompletionItemKind::Snippet)
+        .snippet_edit(cap, edit)
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Postfix);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn postfix_completion_works_for_trivial_path_expression() {
+        check(
+            r#"
+fn main() {
+    let bar = true;
+    bar.<|>
+}
+"#,
+            expect![[r#"
+                sn box   Box::new(expr)
+                sn call  function(expr)
+                sn dbg   dbg!(expr)
+                sn if    if expr {}
+                sn match match expr {}
+                sn not   !expr
+                sn ref   &expr
+                sn refm  &mut expr
+                sn while while expr {}
+            "#]],
+        );
+    }
+
+    #[test]
+    fn postfix_type_filtering() {
+        check(
+            r#"
+fn main() {
+    let bar: u8 = 12;
+    bar.<|>
+}
+"#,
+            expect![[r#"
+                sn box   Box::new(expr)
+                sn call  function(expr)
+                sn dbg   dbg!(expr)
+                sn match match expr {}
+                sn ref   &expr
+                sn refm  &mut expr
+            "#]],
+        )
+    }
+
+    #[test]
+    fn option_iflet() {
+        check_edit(
+            "ifl",
+            r#"
+enum Option<T> { Some(T), None }
+
+fn main() {
+    let bar = Option::Some(true);
+    bar.<|>
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
+
+fn main() {
+    let bar = Option::Some(true);
+    if let Some($1) = bar {
+    $0
+}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn result_match() {
+        check_edit(
+            "match",
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+
+fn main() {
+    let bar = Result::Ok(true);
+    bar.<|>
+}
+"#,
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+
+fn main() {
+    let bar = Result::Ok(true);
+    match bar {
+    Ok(${1:_}) => {$2},
+    Err(${3:_}) => {$0},
+}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn postfix_completion_works_for_ambiguous_float_literal() {
+        check_edit("refm", r#"fn main() { 42.<|> }"#, r#"fn main() { &mut 42 }"#)
+    }
+
+    #[test]
+    fn works_in_simple_macro() {
+        check_edit(
+            "dbg",
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn main() {
+    let bar: u8 = 12;
+    m!(bar.d<|>)
+}
+"#,
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn main() {
+    let bar: u8 = 12;
+    m!(dbg!(bar))
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn postfix_completion_for_references() {
+        check_edit("dbg", r#"fn main() { &&42.<|> }"#, r#"fn main() { dbg!(&&42) }"#);
+        check_edit("refm", r#"fn main() { &&42.<|> }"#, r#"fn main() { &&&mut 42 }"#);
+    }
+}
diff --git a/crates/ide/src/completion/complete_qualified_path.rs b/crates/ide/src/completion/complete_qualified_path.rs
new file mode 100644
index 000000000..cb7dd23c1
--- /dev/null
+++ b/crates/ide/src/completion/complete_qualified_path.rs
@@ -0,0 +1,733 @@
+//! Completion of paths, i.e. `some::prefix::<|>`.
+
+use hir::{Adt, HasVisibility, PathResolution, ScopeDef};
+use rustc_hash::FxHashSet;
+use syntax::AstNode;
+use test_utils::mark;
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionContext) {
+    let path = match &ctx.path_prefix {
+        Some(path) => path.clone(),
+        None => return,
+    };
+
+    if ctx.attribute_under_caret.is_some() {
+        return;
+    }
+
+    let context_module = ctx.scope.module();
+
+    let resolution = match ctx.scope.resolve_hir_path_qualifier(&path) {
+        Some(res) => res,
+        None => return,
+    };
+
+    // Add associated types on type parameters and `Self`.
+    resolution.assoc_type_shorthand_candidates(ctx.db, |alias| {
+        acc.add_type_alias(ctx, alias);
+        None::<()>
+    });
+
+    match resolution {
+        PathResolution::Def(hir::ModuleDef::Module(module)) => {
+            let module_scope = module.scope(ctx.db, context_module);
+            for (name, def) in module_scope {
+                if ctx.use_item_syntax.is_some() {
+                    if let ScopeDef::Unknown = def {
+                        if let Some(name_ref) = ctx.name_ref_syntax.as_ref() {
+                            if name_ref.syntax().text() == name.to_string().as_str() {
+                                // for `use self::foo<|>`, don't suggest `foo` as a completion
+                                mark::hit!(dont_complete_current_use);
+                                continue;
+                            }
+                        }
+                    }
+                }
+
+                acc.add_resolution(ctx, name.to_string(), &def);
+            }
+        }
+        PathResolution::Def(def @ hir::ModuleDef::Adt(_))
+        | PathResolution::Def(def @ hir::ModuleDef::TypeAlias(_)) => {
+            if let hir::ModuleDef::Adt(Adt::Enum(e)) = def {
+                for variant in e.variants(ctx.db) {
+                    acc.add_enum_variant(ctx, variant, None);
+                }
+            }
+            let ty = match def {
+                hir::ModuleDef::Adt(adt) => adt.ty(ctx.db),
+                hir::ModuleDef::TypeAlias(a) => a.ty(ctx.db),
+                _ => unreachable!(),
+            };
+
+            // XXX: For parity with Rust bug #22519, this does not complete Ty::AssocType.
+            // (where AssocType is defined on a trait, not an inherent impl)
+
+            let krate = ctx.krate;
+            if let Some(krate) = krate {
+                let traits_in_scope = ctx.scope.traits_in_scope();
+                ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
+                    if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
+                        return None;
+                    }
+                    match item {
+                        hir::AssocItem::Function(func) => {
+                            acc.add_function(ctx, func, None);
+                        }
+                        hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                        hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                    }
+                    None::<()>
+                });
+
+                // Iterate assoc types separately
+                ty.iterate_assoc_items(ctx.db, krate, |item| {
+                    if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
+                        return None;
+                    }
+                    match item {
+                        hir::AssocItem::Function(_) | hir::AssocItem::Const(_) => {}
+                        hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                    }
+                    None::<()>
+                });
+            }
+        }
+        PathResolution::Def(hir::ModuleDef::Trait(t)) => {
+            // Handles `Trait::assoc` as well as `<Ty as Trait>::assoc`.
+            for item in t.items(ctx.db) {
+                if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
+                    continue;
+                }
+                match item {
+                    hir::AssocItem::Function(func) => {
+                        acc.add_function(ctx, func, None);
+                    }
+                    hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                    hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                }
+            }
+        }
+        PathResolution::TypeParam(_) | PathResolution::SelfType(_) => {
+            if let Some(krate) = ctx.krate {
+                let ty = match resolution {
+                    PathResolution::TypeParam(param) => param.ty(ctx.db),
+                    PathResolution::SelfType(impl_def) => impl_def.target_ty(ctx.db),
+                    _ => return,
+                };
+
+                let traits_in_scope = ctx.scope.traits_in_scope();
+                let mut seen = FxHashSet::default();
+                ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
+                    if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
+                        return None;
+                    }
+
+                    // We might iterate candidates of a trait multiple times here, so deduplicate
+                    // them.
+                    if seen.insert(item) {
+                        match item {
+                            hir::AssocItem::Function(func) => {
+                                acc.add_function(ctx, func, None);
+                            }
+                            hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                            hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                        }
+                    }
+                    None::<()>
+                });
+            }
+        }
+        _ => {}
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
+    }
+
+    fn check_builtin(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::BuiltinType);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn dont_complete_current_use() {
+        mark::check!(dont_complete_current_use);
+        check(r#"use self::foo<|>;"#, expect![[""]]);
+    }
+
+    #[test]
+    fn dont_complete_current_use_in_braces_with_glob() {
+        check(
+            r#"
+mod foo { pub struct S; }
+use self::{foo::*, bar<|>};
+"#,
+            expect![[r#"
+                st S
+                md foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn dont_complete_primitive_in_use() {
+        check_builtin(r#"use self::<|>;"#, expect![[""]]);
+    }
+
+    #[test]
+    fn dont_complete_primitive_in_module_scope() {
+        check_builtin(r#"fn foo() { self::<|> }"#, expect![[""]]);
+    }
+
+    #[test]
+    fn completes_primitives() {
+        check_builtin(
+            r#"fn main() { let _: <|> = 92; }"#,
+            expect![[r#"
+                bt bool
+                bt char
+                bt f32
+                bt f64
+                bt i128
+                bt i16
+                bt i32
+                bt i64
+                bt i8
+                bt isize
+                bt str
+                bt u128
+                bt u16
+                bt u32
+                bt u64
+                bt u8
+                bt usize
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_mod_with_same_name_as_function() {
+        check(
+            r#"
+use self::my::<|>;
+
+mod my { pub struct Bar; }
+fn my() {}
+"#,
+            expect![[r#"
+                st Bar
+            "#]],
+        );
+    }
+
+    #[test]
+    fn filters_visibility() {
+        check(
+            r#"
+use self::my::<|>;
+
+mod my {
+    struct Bar;
+    pub struct Foo;
+    pub use Bar as PublicBar;
+}
+"#,
+            expect![[r#"
+                st Foo
+                st PublicBar
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_use_item_starting_with_self() {
+        check(
+            r#"
+use self::m::<|>;
+
+mod m { pub struct Bar; }
+"#,
+            expect![[r#"
+                st Bar
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_use_item_starting_with_crate() {
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+struct Spam;
+//- /foo.rs
+use crate::Sp<|>
+"#,
+            expect![[r#"
+                st Spam
+                md foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_nested_use_tree() {
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+struct Spam;
+//- /foo.rs
+use crate::{Sp<|>};
+"#,
+            expect![[r#"
+                st Spam
+                md foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_deeply_nested_use_tree() {
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+pub mod bar {
+    pub mod baz {
+        pub struct Spam;
+    }
+}
+//- /foo.rs
+use crate::{bar::{baz::Sp<|>}};
+"#,
+            expect![[r#"
+                st Spam
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_enum_variant() {
+        check(
+            r#"
+enum E { Foo, Bar(i32) }
+fn foo() { let _ = E::<|> }
+"#,
+            expect![[r#"
+                ev Bar(…) (i32)
+                ev Foo    ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_struct_associated_items() {
+        check(
+            r#"
+//- /lib.rs
+struct S;
+
+impl S {
+    fn a() {}
+    fn b(&self) {}
+    const C: i32 = 42;
+    type T = i32;
+}
+
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                ct C   const C: i32 = 42;
+                ta T   type T = i32;
+                fn a() fn a()
+                me b() fn b(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn associated_item_visibility() {
+        check(
+            r#"
+struct S;
+
+mod m {
+    impl super::S {
+        pub(super) fn public_method() { }
+        fn private_method() { }
+        pub(super) type PublicType = u32;
+        type PrivateType = u32;
+        pub(super) const PUBLIC_CONST: u32 = 1;
+        const PRIVATE_CONST: u32 = 1;
+    }
+}
+
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                ct PUBLIC_CONST    pub(super) const PUBLIC_CONST: u32 = 1;
+                ta PublicType      pub(super) type PublicType = u32;
+                fn public_method() pub(super) fn public_method()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_enum_associated_method() {
+        check(
+            r#"
+enum E {};
+impl E { fn m() { } }
+
+fn foo() { let _ = E::<|> }
+        "#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_union_associated_method() {
+        check(
+            r#"
+union U {};
+impl U { fn m() { } }
+
+fn foo() { let _ = U::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_use_paths_across_crates() {
+        check(
+            r#"
+//- /main.rs
+use foo::<|>;
+
+//- /foo/lib.rs
+pub mod bar { pub struct S; }
+"#,
+            expect![[r#"
+                md bar
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_trait_associated_method_1() {
+        check(
+            r#"
+trait Trait { fn m(); }
+
+fn foo() { let _ = Trait::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_trait_associated_method_2() {
+        check(
+            r#"
+trait Trait { fn m(); }
+
+struct S;
+impl Trait for S {}
+
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_trait_associated_method_3() {
+        check(
+            r#"
+trait Trait { fn m(); }
+
+struct S;
+impl Trait for S {}
+
+fn foo() { let _ = <S as Trait>::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_ty_param_assoc_ty() {
+        check(
+            r#"
+trait Super {
+    type Ty;
+    const CONST: u8;
+    fn func() {}
+    fn method(&self) {}
+}
+
+trait Sub: Super {
+    type SubTy;
+    const C2: ();
+    fn subfunc() {}
+    fn submethod(&self) {}
+}
+
+fn foo<T: Sub>() { T::<|> }
+"#,
+            expect![[r#"
+                ct C2          const C2: ();
+                ct CONST       const CONST: u8;
+                ta SubTy       type SubTy;
+                ta Ty          type Ty;
+                fn func()      fn func()
+                me method()    fn method(&self)
+                fn subfunc()   fn subfunc()
+                me submethod() fn submethod(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_self_param_assoc_ty() {
+        check(
+            r#"
+trait Super {
+    type Ty;
+    const CONST: u8 = 0;
+    fn func() {}
+    fn method(&self) {}
+}
+
+trait Sub: Super {
+    type SubTy;
+    const C2: () = ();
+    fn subfunc() {}
+    fn submethod(&self) {}
+}
+
+struct Wrap<T>(T);
+impl<T> Super for Wrap<T> {}
+impl<T> Sub for Wrap<T> {
+    fn subfunc() {
+        // Should be able to assume `Self: Sub + Super`
+        Self::<|>
+    }
+}
+"#,
+            expect![[r#"
+                ct C2          const C2: () = ();
+                ct CONST       const CONST: u8 = 0;
+                ta SubTy       type SubTy;
+                ta Ty          type Ty;
+                fn func()      fn func()
+                me method()    fn method(&self)
+                fn subfunc()   fn subfunc()
+                me submethod() fn submethod(&self)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_type_alias() {
+        check(
+            r#"
+struct S;
+impl S { fn foo() {} }
+type T = S;
+impl T { fn bar() {} }
+
+fn main() { T::<|>; }
+"#,
+            expect![[r#"
+                fn bar() fn bar()
+                fn foo() fn foo()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_qualified_macros() {
+        check(
+            r#"
+#[macro_export]
+macro_rules! foo { () => {} }
+
+fn main() { let _ = crate::<|> }
+        "#,
+            expect![[r##"
+                ma foo!(…) #[macro_export]
+                macro_rules! foo
+                fn main()  fn main()
+            "##]],
+        );
+    }
+
+    #[test]
+    fn test_super_super_completion() {
+        check(
+            r#"
+mod a {
+    const A: usize = 0;
+    mod b {
+        const B: usize = 0;
+        mod c { use super::super::<|> }
+    }
+}
+"#,
+            expect![[r#"
+                ct A
+                md b
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_reexported_items_under_correct_name() {
+        check(
+            r#"
+fn foo() { self::m::<|> }
+
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
+            expect![[r#"
+                ct RIGHT_CONST
+                st RightType
+                fn right_fn()  fn wrong_fn()
+            "#]],
+        );
+
+        check_edit(
+            "RightType",
+            r#"
+fn foo() { self::m::<|> }
+
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
+            r#"
+fn foo() { self::m::RightType }
+
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn completes_in_simple_macro_call() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn main() { m!(self::f<|>); }
+fn foo() {}
+"#,
+            expect![[r#"
+                fn foo()  fn foo()
+                fn main() fn main()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn function_mod_share_name() {
+        check(
+            r#"
+fn foo() { self::m::<|> }
+
+mod m {
+    pub mod z {}
+    pub fn z() {}
+}
+"#,
+            expect![[r#"
+                md z
+                fn z() pub fn z()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_hashmap_new() {
+        check(
+            r#"
+struct RandomState;
+struct HashMap<K, V, S = RandomState> {}
+
+impl<K, V> HashMap<K, V, RandomState> {
+    pub fn new() -> HashMap<K, V, RandomState> { }
+}
+fn foo() {
+    HashMap::<|>
+}
+"#,
+            expect![[r#"
+                fn new() pub fn new() -> HashMap<K, V, RandomState>
+            "#]],
+        );
+    }
+
+    #[test]
+    fn dont_complete_attr() {
+        check(
+            r#"
+mod foo { pub struct Foo; }
+#[foo::<|>]
+fn f() {}
+"#,
+            expect![[""]],
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_record.rs b/crates/ide/src/completion/complete_record.rs
new file mode 100644
index 000000000..74b94594d
--- /dev/null
+++ b/crates/ide/src/completion/complete_record.rs
@@ -0,0 +1,226 @@
+//! Complete fields in record literals and patterns.
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
+    let missing_fields = match (ctx.record_pat_syntax.as_ref(), ctx.record_lit_syntax.as_ref()) {
+        (None, None) => return None,
+        (Some(_), Some(_)) => unreachable!("A record cannot be both a literal and a pattern"),
+        (Some(record_pat), _) => ctx.sema.record_pattern_missing_fields(record_pat),
+        (_, Some(record_lit)) => ctx.sema.record_literal_missing_fields(record_lit),
+    };
+
+    for (field, ty) in missing_fields {
+        acc.add_field(ctx, field, &ty)
+    }
+
+    Some(())
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn test_record_pattern_field() {
+        check(
+            r#"
+struct S { foo: u32 }
+
+fn process(f: S) {
+    match f {
+        S { f<|>: 92 } => (),
+    }
+}
+"#,
+            expect![[r#"
+                fd foo u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_pattern_enum_variant() {
+        check(
+            r#"
+enum E { S { foo: u32, bar: () } }
+
+fn process(e: E) {
+    match e {
+        E::S { <|> } => (),
+    }
+}
+"#,
+            expect![[r#"
+                fd bar ()
+                fd foo u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_pattern_field_in_simple_macro() {
+        check(
+            r"
+macro_rules! m { ($e:expr) => { $e } }
+struct S { foo: u32 }
+
+fn process(f: S) {
+    m!(match f {
+        S { f<|>: 92 } => (),
+    })
+}
+",
+            expect![[r#"
+                fd foo u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn only_missing_fields_are_completed_in_destruct_pats() {
+        check(
+            r#"
+struct S {
+    foo1: u32, foo2: u32,
+    bar: u32, baz: u32,
+}
+
+fn main() {
+    let s = S {
+        foo1: 1, foo2: 2,
+        bar: 3, baz: 4,
+    };
+    if let S { foo1, foo2: a, <|> } = s {}
+}
+"#,
+            expect![[r#"
+                fd bar u32
+                fd baz u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_literal_field() {
+        check(
+            r#"
+struct A { the_field: u32 }
+fn foo() {
+   A { the<|> }
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_literal_enum_variant() {
+        check(
+            r#"
+enum E { A { a: u32 } }
+fn foo() {
+    let _ = E::A { <|> }
+}
+"#,
+            expect![[r#"
+                fd a u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_literal_two_structs() {
+        check(
+            r#"
+struct A { a: u32 }
+struct B { b: u32 }
+
+fn foo() {
+   let _: A = B { <|> }
+}
+"#,
+            expect![[r#"
+                fd b u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_literal_generic_struct() {
+        check(
+            r#"
+struct A<T> { a: T }
+
+fn foo() {
+   let _: A<u32> = A { <|> }
+}
+"#,
+            expect![[r#"
+                fd a u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_record_literal_field_in_simple_macro() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo() {
+   m!(A { the<|> })
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn only_missing_fields_are_completed() {
+        check(
+            r#"
+struct S {
+    foo1: u32, foo2: u32,
+    bar: u32, baz: u32,
+}
+
+fn main() {
+    let foo1 = 1;
+    let s = S { foo1, foo2: 5, <|> }
+}
+"#,
+            expect![[r#"
+                fd bar u32
+                fd baz u32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_functional_update() {
+        check(
+            r#"
+struct S { foo1: u32, foo2: u32 }
+
+fn main() {
+    let foo1 = 1;
+    let s = S { foo1, <|> .. loop {} }
+}
+"#,
+            expect![[r#"
+                fd foo2 u32
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_snippet.rs b/crates/ide/src/completion/complete_snippet.rs
new file mode 100644
index 000000000..4368e4eec
--- /dev/null
+++ b/crates/ide/src/completion/complete_snippet.rs
@@ -0,0 +1,116 @@
+//! FIXME: write short doc here
+
+use crate::completion::{
+    completion_config::SnippetCap, completion_item::Builder, CompletionContext, CompletionItem,
+    CompletionItemKind, CompletionKind, Completions,
+};
+
+fn snippet(ctx: &CompletionContext, cap: SnippetCap, label: &str, snippet: &str) -> Builder {
+    CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label)
+        .insert_snippet(cap, snippet)
+        .kind(CompletionItemKind::Snippet)
+}
+
+pub(super) fn complete_expr_snippet(acc: &mut Completions, ctx: &CompletionContext) {
+    if !(ctx.is_trivial_path && ctx.function_syntax.is_some()) {
+        return;
+    }
+    let cap = match ctx.config.snippet_cap {
+        Some(it) => it,
+        None => return,
+    };
+
+    snippet(ctx, cap, "pd", "eprintln!(\"$0 = {:?}\", $0);").add_to(acc);
+    snippet(ctx, cap, "ppd", "eprintln!(\"$0 = {:#?}\", $0);").add_to(acc);
+}
+
+pub(super) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.is_new_item {
+        return;
+    }
+    let cap = match ctx.config.snippet_cap {
+        Some(it) => it,
+        None => return,
+    };
+
+    snippet(
+        ctx,
+        cap,
+        "tmod (Test module)",
+        "\
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ${1:test_name}() {
+        $0
+    }
+}",
+    )
+    .lookup_by("tmod")
+    .add_to(acc);
+
+    snippet(
+        ctx,
+        cap,
+        "tfn (Test function)",
+        "\
+#[test]
+fn ${1:feature}() {
+    $0
+}",
+    )
+    .lookup_by("tfn")
+    .add_to(acc);
+
+    snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}").add_to(acc);
+    snippet(ctx, cap, "pub(crate)", "pub(crate) $0").add_to(acc);
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Snippet);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn completes_snippets_in_expressions() {
+        check(
+            r#"fn foo(x: i32) { <|> }"#,
+            expect![[r#"
+                sn pd
+                sn ppd
+            "#]],
+        );
+    }
+
+    #[test]
+    fn should_not_complete_snippets_in_path() {
+        check(r#"fn foo(x: i32) { ::foo<|> }"#, expect![[""]]);
+        check(r#"fn foo(x: i32) { ::<|> }"#, expect![[""]]);
+    }
+
+    #[test]
+    fn completes_snippets_in_items() {
+        check(
+            r#"
+#[cfg(test)]
+mod tests {
+    <|>
+}
+"#,
+            expect![[r#"
+                sn macro_rules
+                sn pub(crate)
+                sn tfn (Test function)
+                sn tmod (Test module)
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion/complete_trait_impl.rs b/crates/ide/src/completion/complete_trait_impl.rs
new file mode 100644
index 000000000..478e31262
--- /dev/null
+++ b/crates/ide/src/completion/complete_trait_impl.rs
@@ -0,0 +1,488 @@
+//! Completion for associated items in a trait implementation.
+//!
+//! This module adds the completion items related to implementing associated
+//! items within a `impl Trait for Struct` block. The current context node
+//! must be within either a `FN`, `TYPE_ALIAS`, or `CONST` node
+//! and an direct child of an `IMPL`.
+//!
+//! # Examples
+//!
+//! Considering the following trait `impl`:
+//!
+//! ```ignore
+//! trait SomeTrait {
+//!     fn foo();
+//! }
+//!
+//! impl SomeTrait for () {
+//!     fn f<|>
+//! }
+//! ```
+//!
+//! may result in the completion of the following method:
+//!
+//! ```ignore
+//! # trait SomeTrait {
+//! #    fn foo();
+//! # }
+//!
+//! impl SomeTrait for () {
+//!     fn foo() {}<|>
+//! }
+//! ```
+
+use assists::utils::get_missing_assoc_items;
+use hir::{self, Docs, HasSource};
+use syntax::{
+    ast::{self, edit, Impl},
+    AstNode, SyntaxKind, SyntaxNode, TextRange, T,
+};
+use text_edit::TextEdit;
+
+use crate::{
+    completion::{
+        CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
+    },
+    display::function_declaration,
+};
+
+pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext) {
+    if let Some((trigger, impl_def)) = completion_match(ctx) {
+        match trigger.kind() {
+            SyntaxKind::NAME_REF => get_missing_assoc_items(&ctx.sema, &impl_def)
+                .into_iter()
+                .for_each(|item| match item {
+                    hir::AssocItem::Function(fn_item) => {
+                        add_function_impl(&trigger, acc, ctx, fn_item)
+                    }
+                    hir::AssocItem::TypeAlias(type_item) => {
+                        add_type_alias_impl(&trigger, acc, ctx, type_item)
+                    }
+                    hir::AssocItem::Const(const_item) => {
+                        add_const_impl(&trigger, acc, ctx, const_item)
+                    }
+                }),
+
+            SyntaxKind::FN => {
+                for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
+                    .into_iter()
+                    .filter_map(|item| match item {
+                        hir::AssocItem::Function(fn_item) => Some(fn_item),
+                        _ => None,
+                    })
+                {
+                    add_function_impl(&trigger, acc, ctx, missing_fn);
+                }
+            }
+
+            SyntaxKind::TYPE_ALIAS => {
+                for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
+                    .into_iter()
+                    .filter_map(|item| match item {
+                        hir::AssocItem::TypeAlias(type_item) => Some(type_item),
+                        _ => None,
+                    })
+                {
+                    add_type_alias_impl(&trigger, acc, ctx, missing_fn);
+                }
+            }
+
+            SyntaxKind::CONST => {
+                for missing_fn in get_missing_assoc_items(&ctx.sema, &impl_def)
+                    .into_iter()
+                    .filter_map(|item| match item {
+                        hir::AssocItem::Const(const_item) => Some(const_item),
+                        _ => None,
+                    })
+                {
+                    add_const_impl(&trigger, acc, ctx, missing_fn);
+                }
+            }
+
+            _ => {}
+        }
+    }
+}
+
+fn completion_match(ctx: &CompletionContext) -> Option<(SyntaxNode, Impl)> {
+    let (trigger, impl_def_offset) = ctx.token.ancestors().find_map(|p| match p.kind() {
+        SyntaxKind::FN | SyntaxKind::TYPE_ALIAS | SyntaxKind::CONST | SyntaxKind::BLOCK_EXPR => {
+            Some((p, 2))
+        }
+        SyntaxKind::NAME_REF => Some((p, 5)),
+        _ => None,
+    })?;
+    let impl_def = (0..impl_def_offset - 1)
+        .try_fold(trigger.parent()?, |t, _| t.parent())
+        .and_then(ast::Impl::cast)?;
+    Some((trigger, impl_def))
+}
+
+fn add_function_impl(
+    fn_def_node: &SyntaxNode,
+    acc: &mut Completions,
+    ctx: &CompletionContext,
+    func: hir::Function,
+) {
+    let fn_name = func.name(ctx.db).to_string();
+
+    let label = if !func.params(ctx.db).is_empty() {
+        format!("fn {}(..)", fn_name)
+    } else {
+        format!("fn {}()", fn_name)
+    };
+
+    let builder = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
+        .lookup_by(fn_name)
+        .set_documentation(func.docs(ctx.db));
+
+    let completion_kind = if func.has_self_param(ctx.db) {
+        CompletionItemKind::Method
+    } else {
+        CompletionItemKind::Function
+    };
+    let range = TextRange::new(fn_def_node.text_range().start(), ctx.source_range().end());
+
+    let function_decl = function_declaration(&func.source(ctx.db).value);
+    match ctx.config.snippet_cap {
+        Some(cap) => {
+            let snippet = format!("{} {{\n    $0\n}}", function_decl);
+            builder.snippet_edit(cap, TextEdit::replace(range, snippet))
+        }
+        None => {
+            let header = format!("{} {{", function_decl);
+            builder.text_edit(TextEdit::replace(range, header))
+        }
+    }
+    .kind(completion_kind)
+    .add_to(acc);
+}
+
+fn add_type_alias_impl(
+    type_def_node: &SyntaxNode,
+    acc: &mut Completions,
+    ctx: &CompletionContext,
+    type_alias: hir::TypeAlias,
+) {
+    let alias_name = type_alias.name(ctx.db).to_string();
+
+    let snippet = format!("type {} = ", alias_name);
+
+    let range = TextRange::new(type_def_node.text_range().start(), ctx.source_range().end());
+
+    CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
+        .text_edit(TextEdit::replace(range, snippet))
+        .lookup_by(alias_name)
+        .kind(CompletionItemKind::TypeAlias)
+        .set_documentation(type_alias.docs(ctx.db))
+        .add_to(acc);
+}
+
+fn add_const_impl(
+    const_def_node: &SyntaxNode,
+    acc: &mut Completions,
+    ctx: &CompletionContext,
+    const_: hir::Const,
+) {
+    let const_name = const_.name(ctx.db).map(|n| n.to_string());
+
+    if let Some(const_name) = const_name {
+        let snippet = make_const_compl_syntax(&const_.source(ctx.db).value);
+
+        let range = TextRange::new(const_def_node.text_range().start(), ctx.source_range().end());
+
+        CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
+            .text_edit(TextEdit::replace(range, snippet))
+            .lookup_by(const_name)
+            .kind(CompletionItemKind::Const)
+            .set_documentation(const_.docs(ctx.db))
+            .add_to(acc);
+    }
+}
+
+fn make_const_compl_syntax(const_: &ast::Const) -> String {
+    let const_ = edit::remove_attrs_and_docs(const_);
+
+    let const_start = const_.syntax().text_range().start();
+    let const_end = const_.syntax().text_range().end();
+
+    let start =
+        const_.syntax().first_child_or_token().map_or(const_start, |f| f.text_range().start());
+
+    let end = const_
+        .syntax()
+        .children_with_tokens()
+        .find(|s| s.kind() == T![;] || s.kind() == T![=])
+        .map_or(const_end, |f| f.text_range().start());
+
+    let len = end - start;
+    let range = TextRange::new(0.into(), len);
+
+    let syntax = const_.syntax().text().slice(range).to_string();
+
+    format!("{} = ", syntax.trim_end())
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Magic);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn name_ref_function_type_const() {
+        check(
+            r#"
+trait Test {
+    type TestType;
+    const TEST_CONST: u16;
+    fn test();
+}
+struct T;
+
+impl Test for T {
+    t<|>
+}
+"#,
+            expect![["
+ct const TEST_CONST: u16 = \n\
+fn fn test()
+ta type TestType = \n\
+            "]],
+        );
+    }
+
+    #[test]
+    fn no_nested_fn_completions() {
+        check(
+            r"
+trait Test {
+    fn test();
+    fn test2();
+}
+struct T;
+
+impl Test for T {
+    fn test() {
+        t<|>
+    }
+}
+",
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn name_ref_single_function() {
+        check_edit(
+            "test",
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
+
+impl Test for T {
+    t<|>
+}
+"#,
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
+
+impl Test for T {
+    fn test() {
+    $0
+}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn single_function() {
+        check_edit(
+            "test",
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
+
+impl Test for T {
+    fn t<|>
+}
+"#,
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
+
+impl Test for T {
+    fn test() {
+    $0
+}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn hide_implemented_fn() {
+        check(
+            r#"
+trait Test {
+    fn foo();
+    fn foo_bar();
+}
+struct T;
+
+impl Test for T {
+    fn foo() {}
+    fn f<|>
+}
+"#,
+            expect![[r#"
+                fn fn foo_bar()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn generic_fn() {
+        check_edit(
+            "foo",
+            r#"
+trait Test {
+    fn foo<T>();
+}
+struct T;
+
+impl Test for T {
+    fn f<|>
+}
+"#,
+            r#"
+trait Test {
+    fn foo<T>();
+}
+struct T;
+
+impl Test for T {
+    fn foo<T>() {
+    $0
+}
+}
+"#,
+        );
+        check_edit(
+            "foo",
+            r#"
+trait Test {
+    fn foo<T>() where T: Into<String>;
+}
+struct T;
+
+impl Test for T {
+    fn f<|>
+}
+"#,
+            r#"
+trait Test {
+    fn foo<T>() where T: Into<String>;
+}
+struct T;
+
+impl Test for T {
+    fn foo<T>()
+where T: Into<String> {
+    $0
+}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn associated_type() {
+        check_edit(
+            "SomeType",
+            r#"
+trait Test {
+    type SomeType;
+}
+
+impl Test for () {
+    type S<|>
+}
+"#,
+            "
+trait Test {
+    type SomeType;
+}
+
+impl Test for () {
+    type SomeType = \n\
+}
+",
+        );
+    }
+
+    #[test]
+    fn associated_const() {
+        check_edit(
+            "SOME_CONST",
+            r#"
+trait Test {
+    const SOME_CONST: u16;
+}
+
+impl Test for () {
+    const S<|>
+}
+"#,
+            "
+trait Test {
+    const SOME_CONST: u16;
+}
+
+impl Test for () {
+    const SOME_CONST: u16 = \n\
+}
+",
+        );
+
+        check_edit(
+            "SOME_CONST",
+            r#"
+trait Test {
+    const SOME_CONST: u16 = 92;
+}
+
+impl Test for () {
+    const S<|>
+}
+"#,
+            "
+trait Test {
+    const SOME_CONST: u16 = 92;
+}
+
+impl Test for () {
+    const SOME_CONST: u16 = \n\
+}
+",
+        );
+    }
+}
diff --git a/crates/ide/src/completion/complete_unqualified_path.rs b/crates/ide/src/completion/complete_unqualified_path.rs
new file mode 100644
index 000000000..824227f31
--- /dev/null
+++ b/crates/ide/src/completion/complete_unqualified_path.rs
@@ -0,0 +1,658 @@
+//! Completion of names from the current scope, e.g. locals and imported items.
+
+use hir::{Adt, ModuleDef, ScopeDef, Type};
+use syntax::AstNode;
+use test_utils::mark;
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
+    if !(ctx.is_trivial_path || ctx.is_pat_binding_or_const) {
+        return;
+    }
+    if ctx.record_lit_syntax.is_some()
+        || ctx.record_pat_syntax.is_some()
+        || ctx.attribute_under_caret.is_some()
+    {
+        return;
+    }
+
+    if let Some(ty) = &ctx.expected_type {
+        complete_enum_variants(acc, ctx, ty);
+    }
+
+    if ctx.is_pat_binding_or_const {
+        return;
+    }
+
+    ctx.scope.process_all_names(&mut |name, res| {
+        if ctx.use_item_syntax.is_some() {
+            if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
+                if name_ref.syntax().text() == name.to_string().as_str() {
+                    mark::hit!(self_fulfilling_completion);
+                    return;
+                }
+            }
+        }
+        acc.add_resolution(ctx, name.to_string(), &res)
+    });
+}
+
+fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &Type) {
+    if let Some(Adt::Enum(enum_data)) = ty.as_adt() {
+        let variants = enum_data.variants(ctx.db);
+
+        let module = if let Some(module) = ctx.scope.module() {
+            // Compute path from the completion site if available.
+            module
+        } else {
+            // Otherwise fall back to the enum's definition site.
+            enum_data.module(ctx.db)
+        };
+
+        for variant in variants {
+            if let Some(path) = module.find_use_path(ctx.db, ModuleDef::from(variant)) {
+                // Variants with trivial paths are already added by the existing completion logic,
+                // so we should avoid adding these twice
+                if path.segments.len() > 1 {
+                    acc.add_qualified_enum_variant(ctx, variant, path);
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn self_fulfilling_completion() {
+        mark::check!(self_fulfilling_completion);
+        check(
+            r#"
+use foo<|>
+use std::collections;
+"#,
+            expect![[r#"
+                ?? collections
+            "#]],
+        );
+    }
+
+    #[test]
+    fn bind_pat_and_path_ignore_at() {
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(en<|> @ Enum::A) => (),
+    }
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn bind_pat_and_path_ignore_ref() {
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(ref en<|>) => (),
+    }
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn bind_pat_and_path() {
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(En<|>) => (),
+    }
+}
+"#,
+            expect![[r#"
+                en Enum
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_bindings_from_let() {
+        check(
+            r#"
+fn quux(x: i32) {
+    let y = 92;
+    1 + <|>;
+    let z = ();
+}
+"#,
+            expect![[r#"
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_bindings_from_if_let() {
+        check(
+            r#"
+fn quux() {
+    if let Some(x) = foo() {
+        let y = 92;
+    };
+    if let Some(a) = bar() {
+        let b = 62;
+        1 + <|>
+    }
+}
+"#,
+            expect![[r#"
+                bn a
+                bn b      i32
+                fn quux() fn quux()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_bindings_from_for() {
+        check(
+            r#"
+fn quux() {
+    for x in &[1, 2, 3] { <|> }
+}
+"#,
+            expect![[r#"
+                fn quux() fn quux()
+                bn x
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_if_prefix_is_keyword() {
+        mark::check!(completes_if_prefix_is_keyword);
+        check_edit(
+            "wherewolf",
+            r#"
+fn main() {
+    let wherewolf = 92;
+    drop(where<|>)
+}
+"#,
+            r#"
+fn main() {
+    let wherewolf = 92;
+    drop(wherewolf)
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn completes_generic_params() {
+        check(
+            r#"fn quux<T>() { <|> }"#,
+            expect![[r#"
+                tp T
+                fn quux() fn quux<T>()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_generic_params_in_struct() {
+        check(
+            r#"struct S<T> { x: <|>}"#,
+            expect![[r#"
+                st S<…>
+                tp Self
+                tp T
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_self_in_enum() {
+        check(
+            r#"enum X { Y(<|>) }"#,
+            expect![[r#"
+                tp Self
+                en X
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_module_items() {
+        check(
+            r#"
+struct S;
+enum E {}
+fn quux() { <|> }
+"#,
+            expect![[r#"
+                en E
+                st S
+                fn quux() fn quux()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_extern_prelude() {
+        check(
+            r#"
+//- /lib.rs
+use <|>;
+
+//- /other_crate/lib.rs
+// nothing here
+"#,
+            expect![[r#"
+                md other_crate
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_module_items_in_nested_modules() {
+        check(
+            r#"
+struct Foo;
+mod m {
+    struct Bar;
+    fn quux() { <|> }
+}
+"#,
+            expect![[r#"
+                st Bar
+                fn quux() fn quux()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_return_type() {
+        check(
+            r#"
+struct Foo;
+fn x() -> <|>
+"#,
+            expect![[r#"
+                st Foo
+                fn x() fn x()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn dont_show_both_completions_for_shadowing() {
+        check(
+            r#"
+fn foo() {
+    let bar = 92;
+    {
+        let bar = 62;
+        drop(<|>)
+    }
+}
+"#,
+            // FIXME: should be only one bar here
+            expect![[r#"
+                bn bar   i32
+                bn bar   i32
+                fn foo() fn foo()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_self_in_methods() {
+        check(
+            r#"impl S { fn foo(&self) { <|> } }"#,
+            expect![[r#"
+                tp Self
+                bn self &{unknown}
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_prelude() {
+        check(
+            r#"
+//- /main.rs
+fn foo() { let x: <|> }
+
+//- /std/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct Option; }
+"#,
+            expect![[r#"
+                st Option
+                fn foo()  fn foo()
+                md std
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_std_prelude_if_core_is_defined() {
+        check(
+            r#"
+//- /main.rs
+fn foo() { let x: <|> }
+
+//- /core/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct Option; }
+
+//- /std/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct String; }
+"#,
+            expect![[r#"
+                st String
+                md core
+                fn foo()  fn foo()
+                md std
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_macros_as_value() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+
+#[macro_use]
+mod m1 {
+    macro_rules! bar { () => {} }
+}
+
+mod m2 {
+    macro_rules! nope { () => {} }
+
+    #[macro_export]
+    macro_rules! baz { () => {} }
+}
+
+fn main() { let v = <|> }
+"#,
+            expect![[r##"
+                ma bar!(…) macro_rules! bar
+                ma baz!(…) #[macro_export]
+                macro_rules! baz
+                ma foo!(…) macro_rules! foo
+                md m1
+                md m2
+                fn main()  fn main()
+            "##]],
+        );
+    }
+
+    #[test]
+    fn completes_both_macro_and_value() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn foo() { <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn foo()   fn foo()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_macros_as_type() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn main() { let x: <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn main()  fn main()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_macros_as_stmt() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn main() { <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn main()  fn main()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_local_item() {
+        check(
+            r#"
+fn main() {
+    return f<|>;
+    fn frobnicate() {}
+}
+"#,
+            expect![[r#"
+                fn frobnicate() fn frobnicate()
+                fn main()       fn main()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_in_simple_macro_1() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(<|>);
+}
+"#,
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_in_simple_macro_2() {
+        check(
+            r"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(x<|>);
+}
+",
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_in_simple_macro_without_closing_parens() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(x<|>
+}
+"#,
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_unresolved_uses() {
+        check(
+            r#"
+use spam::Quux;
+
+fn main() { <|> }
+"#,
+            expect![[r#"
+                ?? Quux
+                fn main() fn main()
+            "#]],
+        );
+    }
+    #[test]
+    fn completes_enum_variant_matcharm() {
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
+
+fn main() {
+    let foo = Foo::Quux;
+    match foo { Qu<|> }
+}
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+            "#]],
+        )
+    }
+
+    #[test]
+    fn completes_enum_variant_iflet() {
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
+
+fn main() {
+    let foo = Foo::Quux;
+    if let Qu<|> = foo { }
+}
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+            "#]],
+        )
+    }
+
+    #[test]
+    fn completes_enum_variant_basic_expr() {
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
+fn main() { let foo: Foo = Q<|> }
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+                fn main()    fn main()
+            "#]],
+        )
+    }
+
+    #[test]
+    fn completes_enum_variant_from_module() {
+        check(
+            r#"
+mod m { pub enum E { V } }
+fn f() -> m::E { V<|> }
+"#,
+            expect![[r#"
+                fn f()     fn f() -> m::E
+                md m
+                ev m::E::V ()
+            "#]],
+        )
+    }
+
+    #[test]
+    fn dont_complete_attr() {
+        check(
+            r#"
+struct Foo;
+#[<|>]
+fn f() {}
+"#,
+            expect![[""]],
+        )
+    }
+
+    #[test]
+    fn completes_type_or_trait_in_impl_block() {
+        check(
+            r#"
+trait MyTrait {}
+struct MyStruct {}
+
+impl My<|>
+"#,
+            expect![[r#"
+                st MyStruct
+                tt MyTrait
+                tp Self
+            "#]],
+        )
+    }
+}
diff --git a/crates/ide/src/completion/completion_config.rs b/crates/ide/src/completion/completion_config.rs
new file mode 100644
index 000000000..71b49ace8
--- /dev/null
+++ b/crates/ide/src/completion/completion_config.rs
@@ -0,0 +1,35 @@
+//! Settings for tweaking completion.
+//!
+//! The fun thing here is `SnippetCap` -- this type can only be created in this
+//! module, and we use to statically check that we only produce snippet
+//! completions if we are allowed to.
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct CompletionConfig {
+    pub enable_postfix_completions: bool,
+    pub add_call_parenthesis: bool,
+    pub add_call_argument_snippets: bool,
+    pub snippet_cap: Option<SnippetCap>,
+}
+
+impl CompletionConfig {
+    pub fn allow_snippets(&mut self, yes: bool) {
+        self.snippet_cap = if yes { Some(SnippetCap { _private: () }) } else { None }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct SnippetCap {
+    _private: (),
+}
+
+impl Default for CompletionConfig {
+    fn default() -> Self {
+        CompletionConfig {
+            enable_postfix_completions: true,
+            add_call_parenthesis: true,
+            add_call_argument_snippets: true,
+            snippet_cap: Some(SnippetCap { _private: () }),
+        }
+    }
+}
diff --git a/crates/ide/src/completion/completion_context.rs b/crates/ide/src/completion/completion_context.rs
new file mode 100644
index 000000000..047ecd9d7
--- /dev/null
+++ b/crates/ide/src/completion/completion_context.rs
@@ -0,0 +1,465 @@
+//! FIXME: write short doc here
+
+use base_db::SourceDatabase;
+use hir::{Semantics, SemanticsScope, Type};
+use ide_db::RootDatabase;
+use syntax::{
+    algo::{find_covering_element, find_node_at_offset},
+    ast, match_ast, AstNode, NodeOrToken,
+    SyntaxKind::*,
+    SyntaxNode, SyntaxToken, TextRange, TextSize,
+};
+use text_edit::Indel;
+
+use super::patterns::{
+    has_bind_pat_parent, has_block_expr_parent, has_impl_as_prev_sibling, has_impl_parent,
+    has_item_list_or_source_file_parent, has_ref_parent, has_trait_as_prev_sibling,
+    has_trait_parent, if_is_prev, is_in_loop_body, is_match_arm, unsafe_is_prev,
+};
+use crate::{call_info::ActiveParameter, completion::CompletionConfig, FilePosition};
+use test_utils::mark;
+
+/// `CompletionContext` is created early during completion to figure out, where
+/// exactly is the cursor, syntax-wise.
+#[derive(Debug)]
+pub(crate) struct CompletionContext<'a> {
+    pub(super) sema: Semantics<'a, RootDatabase>,
+    pub(super) scope: SemanticsScope<'a>,
+    pub(super) db: &'a RootDatabase,
+    pub(super) config: &'a CompletionConfig,
+    pub(super) position: FilePosition,
+    /// The token before the cursor, in the original file.
+    pub(super) original_token: SyntaxToken,
+    /// The token before the cursor, in the macro-expanded file.
+    pub(super) token: SyntaxToken,
+    pub(super) krate: Option<hir::Crate>,
+    pub(super) expected_type: Option<Type>,
+    pub(super) name_ref_syntax: Option<ast::NameRef>,
+    pub(super) function_syntax: Option<ast::Fn>,
+    pub(super) use_item_syntax: Option<ast::Use>,
+    pub(super) record_lit_syntax: Option<ast::RecordExpr>,
+    pub(super) record_pat_syntax: Option<ast::RecordPat>,
+    pub(super) record_field_syntax: Option<ast::RecordExprField>,
+    pub(super) impl_def: Option<ast::Impl>,
+    /// FIXME: `ActiveParameter` is string-based, which is very very wrong
+    pub(super) active_parameter: Option<ActiveParameter>,
+    pub(super) is_param: bool,
+    /// If a name-binding or reference to a const in a pattern.
+    /// Irrefutable patterns (like let) are excluded.
+    pub(super) is_pat_binding_or_const: bool,
+    /// A single-indent path, like `foo`. `::foo` should not be considered a trivial path.
+    pub(super) is_trivial_path: bool,
+    /// If not a trivial path, the prefix (qualifier).
+    pub(super) path_prefix: Option<hir::Path>,
+    pub(super) after_if: bool,
+    /// `true` if we are a statement or a last expr in the block.
+    pub(super) can_be_stmt: bool,
+    /// `true` if we expect an expression at the cursor position.
+    pub(super) is_expr: bool,
+    /// Something is typed at the "top" level, in module or impl/trait.
+    pub(super) is_new_item: bool,
+    /// The receiver if this is a field or method access, i.e. writing something.<|>
+    pub(super) dot_receiver: Option<ast::Expr>,
+    pub(super) dot_receiver_is_ambiguous_float_literal: bool,
+    /// If this is a call (method or function) in particular, i.e. the () are already there.
+    pub(super) is_call: bool,
+    /// Like `is_call`, but for tuple patterns.
+    pub(super) is_pattern_call: bool,
+    /// If this is a macro call, i.e. the () are already there.
+    pub(super) is_macro_call: bool,
+    pub(super) is_path_type: bool,
+    pub(super) has_type_args: bool,
+    pub(super) attribute_under_caret: Option<ast::Attr>,
+    pub(super) unsafe_is_prev: bool,
+    pub(super) if_is_prev: bool,
+    pub(super) block_expr_parent: bool,
+    pub(super) bind_pat_parent: bool,
+    pub(super) ref_pat_parent: bool,
+    pub(super) in_loop_body: bool,
+    pub(super) has_trait_parent: bool,
+    pub(super) has_impl_parent: bool,
+    pub(super) trait_as_prev_sibling: bool,
+    pub(super) impl_as_prev_sibling: bool,
+    pub(super) is_match_arm: bool,
+    pub(super) has_item_list_or_source_file_parent: bool,
+}
+
+impl<'a> CompletionContext<'a> {
+    pub(super) fn new(
+        db: &'a RootDatabase,
+        position: FilePosition,
+        config: &'a CompletionConfig,
+    ) -> Option<CompletionContext<'a>> {
+        let sema = Semantics::new(db);
+
+        let original_file = sema.parse(position.file_id);
+
+        // Insert a fake ident to get a valid parse tree. We will use this file
+        // to determine context, though the original_file will be used for
+        // actual completion.
+        let file_with_fake_ident = {
+            let parse = db.parse(position.file_id);
+            let edit = Indel::insert(position.offset, "intellijRulezz".to_string());
+            parse.reparse(&edit).tree()
+        };
+        let fake_ident_token =
+            file_with_fake_ident.syntax().token_at_offset(position.offset).right_biased().unwrap();
+
+        let krate = sema.to_module_def(position.file_id).map(|m| m.krate());
+        let original_token =
+            original_file.syntax().token_at_offset(position.offset).left_biased()?;
+        let token = sema.descend_into_macros(original_token.clone());
+        let scope = sema.scope_at_offset(&token.parent(), position.offset);
+        let mut ctx = CompletionContext {
+            sema,
+            scope,
+            db,
+            config,
+            original_token,
+            token,
+            position,
+            krate,
+            expected_type: None,
+            name_ref_syntax: None,
+            function_syntax: None,
+            use_item_syntax: None,
+            record_lit_syntax: None,
+            record_pat_syntax: None,
+            record_field_syntax: None,
+            impl_def: None,
+            active_parameter: ActiveParameter::at(db, position),
+            is_param: false,
+            is_pat_binding_or_const: false,
+            is_trivial_path: false,
+            path_prefix: None,
+            after_if: false,
+            can_be_stmt: false,
+            is_expr: false,
+            is_new_item: false,
+            dot_receiver: None,
+            is_call: false,
+            is_pattern_call: false,
+            is_macro_call: false,
+            is_path_type: false,
+            has_type_args: false,
+            dot_receiver_is_ambiguous_float_literal: false,
+            attribute_under_caret: None,
+            unsafe_is_prev: false,
+            in_loop_body: false,
+            ref_pat_parent: false,
+            bind_pat_parent: false,
+            block_expr_parent: false,
+            has_trait_parent: false,
+            has_impl_parent: false,
+            trait_as_prev_sibling: false,
+            impl_as_prev_sibling: false,
+            if_is_prev: false,
+            is_match_arm: false,
+            has_item_list_or_source_file_parent: false,
+        };
+
+        let mut original_file = original_file.syntax().clone();
+        let mut hypothetical_file = file_with_fake_ident.syntax().clone();
+        let mut offset = position.offset;
+        let mut fake_ident_token = fake_ident_token;
+
+        // Are we inside a macro call?
+        while let (Some(actual_macro_call), Some(macro_call_with_fake_ident)) = (
+            find_node_at_offset::<ast::MacroCall>(&original_file, offset),
+            find_node_at_offset::<ast::MacroCall>(&hypothetical_file, offset),
+        ) {
+            if actual_macro_call.path().as_ref().map(|s| s.syntax().text())
+                != macro_call_with_fake_ident.path().as_ref().map(|s| s.syntax().text())
+            {
+                break;
+            }
+            let hypothetical_args = match macro_call_with_fake_ident.token_tree() {
+                Some(tt) => tt,
+                None => break,
+            };
+            if let (Some(actual_expansion), Some(hypothetical_expansion)) = (
+                ctx.sema.expand(&actual_macro_call),
+                ctx.sema.expand_hypothetical(
+                    &actual_macro_call,
+                    &hypothetical_args,
+                    fake_ident_token,
+                ),
+            ) {
+                let new_offset = hypothetical_expansion.1.text_range().start();
+                if new_offset > actual_expansion.text_range().end() {
+                    break;
+                }
+                original_file = actual_expansion;
+                hypothetical_file = hypothetical_expansion.0;
+                fake_ident_token = hypothetical_expansion.1;
+                offset = new_offset;
+            } else {
+                break;
+            }
+        }
+        ctx.fill_keyword_patterns(&hypothetical_file, offset);
+        ctx.fill(&original_file, hypothetical_file, offset);
+        Some(ctx)
+    }
+
+    // The range of the identifier that is being completed.
+    pub(crate) fn source_range(&self) -> TextRange {
+        // check kind of macro-expanded token, but use range of original token
+        if self.token.kind() == IDENT || self.token.kind().is_keyword() {
+            mark::hit!(completes_if_prefix_is_keyword);
+            self.original_token.text_range()
+        } else {
+            TextRange::empty(self.position.offset)
+        }
+    }
+
+    fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) {
+        let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap();
+        let syntax_element = NodeOrToken::Token(fake_ident_token);
+        self.block_expr_parent = has_block_expr_parent(syntax_element.clone());
+        self.unsafe_is_prev = unsafe_is_prev(syntax_element.clone());
+        self.if_is_prev = if_is_prev(syntax_element.clone());
+        self.bind_pat_parent = has_bind_pat_parent(syntax_element.clone());
+        self.ref_pat_parent = has_ref_parent(syntax_element.clone());
+        self.in_loop_body = is_in_loop_body(syntax_element.clone());
+        self.has_trait_parent = has_trait_parent(syntax_element.clone());
+        self.has_impl_parent = has_impl_parent(syntax_element.clone());
+        self.impl_as_prev_sibling = has_impl_as_prev_sibling(syntax_element.clone());
+        self.trait_as_prev_sibling = has_trait_as_prev_sibling(syntax_element.clone());
+        self.is_match_arm = is_match_arm(syntax_element.clone());
+        self.has_item_list_or_source_file_parent =
+            has_item_list_or_source_file_parent(syntax_element);
+    }
+
+    fn fill(
+        &mut self,
+        original_file: &SyntaxNode,
+        file_with_fake_ident: SyntaxNode,
+        offset: TextSize,
+    ) {
+        // FIXME: this is wrong in at least two cases:
+        //  * when there's no token `foo(<|>)`
+        //  * when there is a token, but it happens to have type of it's own
+        self.expected_type = self
+            .token
+            .ancestors()
+            .find_map(|node| {
+                let ty = match_ast! {
+                    match node {
+                        ast::Pat(it) => self.sema.type_of_pat(&it),
+                        ast::Expr(it) => self.sema.type_of_expr(&it),
+                        _ => return None,
+                    }
+                };
+                Some(ty)
+            })
+            .flatten();
+        self.attribute_under_caret = find_node_at_offset(&file_with_fake_ident, offset);
+
+        // First, let's try to complete a reference to some declaration.
+        if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(&file_with_fake_ident, offset) {
+            // Special case, `trait T { fn foo(i_am_a_name_ref) {} }`.
+            // See RFC#1685.
+            if is_node::<ast::Param>(name_ref.syntax()) {
+                self.is_param = true;
+                return;
+            }
+            // FIXME: remove this (V) duplication and make the check more precise
+            if name_ref.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() {
+                self.record_pat_syntax =
+                    self.sema.find_node_at_offset_with_macros(&original_file, offset);
+            }
+            self.classify_name_ref(original_file, name_ref, offset);
+        }
+
+        // Otherwise, see if this is a declaration. We can use heuristics to
+        // suggest declaration names, see `CompletionKind::Magic`.
+        if let Some(name) = find_node_at_offset::<ast::Name>(&file_with_fake_ident, offset) {
+            if let Some(bind_pat) = name.syntax().ancestors().find_map(ast::IdentPat::cast) {
+                self.is_pat_binding_or_const = true;
+                if bind_pat.at_token().is_some()
+                    || bind_pat.ref_token().is_some()
+                    || bind_pat.mut_token().is_some()
+                {
+                    self.is_pat_binding_or_const = false;
+                }
+                if bind_pat.syntax().parent().and_then(ast::RecordPatFieldList::cast).is_some() {
+                    self.is_pat_binding_or_const = false;
+                }
+                if let Some(let_stmt) = bind_pat.syntax().ancestors().find_map(ast::LetStmt::cast) {
+                    if let Some(pat) = let_stmt.pat() {
+                        if pat.syntax().text_range().contains_range(bind_pat.syntax().text_range())
+                        {
+                            self.is_pat_binding_or_const = false;
+                        }
+                    }
+                }
+            }
+            if is_node::<ast::Param>(name.syntax()) {
+                self.is_param = true;
+                return;
+            }
+            // FIXME: remove this (^) duplication and make the check more precise
+            if name.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() {
+                self.record_pat_syntax =
+                    self.sema.find_node_at_offset_with_macros(&original_file, offset);
+            }
+        }
+    }
+
+    fn classify_name_ref(
+        &mut self,
+        original_file: &SyntaxNode,
+        name_ref: ast::NameRef,
+        offset: TextSize,
+    ) {
+        self.name_ref_syntax =
+            find_node_at_offset(&original_file, name_ref.syntax().text_range().start());
+        let name_range = name_ref.syntax().text_range();
+        if ast::RecordExprField::for_field_name(&name_ref).is_some() {
+            self.record_lit_syntax =
+                self.sema.find_node_at_offset_with_macros(&original_file, offset);
+        }
+
+        self.impl_def = self
+            .sema
+            .ancestors_with_macros(self.token.parent())
+            .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE)
+            .find_map(ast::Impl::cast);
+
+        let top_node = name_ref
+            .syntax()
+            .ancestors()
+            .take_while(|it| it.text_range() == name_range)
+            .last()
+            .unwrap();
+
+        match top_node.parent().map(|it| it.kind()) {
+            Some(SOURCE_FILE) | Some(ITEM_LIST) => {
+                self.is_new_item = true;
+                return;
+            }
+            _ => (),
+        }
+
+        self.use_item_syntax =
+            self.sema.ancestors_with_macros(self.token.parent()).find_map(ast::Use::cast);
+
+        self.function_syntax = self
+            .sema
+            .ancestors_with_macros(self.token.parent())
+            .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE)
+            .find_map(ast::Fn::cast);
+
+        self.record_field_syntax = self
+            .sema
+            .ancestors_with_macros(self.token.parent())
+            .take_while(|it| {
+                it.kind() != SOURCE_FILE && it.kind() != MODULE && it.kind() != CALL_EXPR
+            })
+            .find_map(ast::RecordExprField::cast);
+
+        let parent = match name_ref.syntax().parent() {
+            Some(it) => it,
+            None => return,
+        };
+
+        if let Some(segment) = ast::PathSegment::cast(parent.clone()) {
+            let path = segment.parent_path();
+            self.is_call = path
+                .syntax()
+                .parent()
+                .and_then(ast::PathExpr::cast)
+                .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::cast))
+                .is_some();
+            self.is_macro_call = path.syntax().parent().and_then(ast::MacroCall::cast).is_some();
+            self.is_pattern_call =
+                path.syntax().parent().and_then(ast::TupleStructPat::cast).is_some();
+
+            self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
+            self.has_type_args = segment.generic_arg_list().is_some();
+
+            let hygiene = hir::Hygiene::new(self.db, self.position.file_id.into());
+            if let Some(path) = hir::Path::from_src(path.clone(), &hygiene) {
+                if let Some(path_prefix) = path.qualifier() {
+                    self.path_prefix = Some(path_prefix);
+                    return;
+                }
+            }
+
+            if path.qualifier().is_none() {
+                self.is_trivial_path = true;
+
+                // Find either enclosing expr statement (thing with `;`) or a
+                // block. If block, check that we are the last expr.
+                self.can_be_stmt = name_ref
+                    .syntax()
+                    .ancestors()
+                    .find_map(|node| {
+                        if let Some(stmt) = ast::ExprStmt::cast(node.clone()) {
+                            return Some(
+                                stmt.syntax().text_range() == name_ref.syntax().text_range(),
+                            );
+                        }
+                        if let Some(block) = ast::BlockExpr::cast(node) {
+                            return Some(
+                                block.expr().map(|e| e.syntax().text_range())
+                                    == Some(name_ref.syntax().text_range()),
+                            );
+                        }
+                        None
+                    })
+                    .unwrap_or(false);
+                self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
+
+                if let Some(off) = name_ref.syntax().text_range().start().checked_sub(2.into()) {
+                    if let Some(if_expr) =
+                        self.sema.find_node_at_offset_with_macros::<ast::IfExpr>(original_file, off)
+                    {
+                        if if_expr.syntax().text_range().end()
+                            < name_ref.syntax().text_range().start()
+                        {
+                            self.after_if = true;
+                        }
+                    }
+                }
+            }
+        }
+        if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) {
+            // The receiver comes before the point of insertion of the fake
+            // ident, so it should have the same range in the non-modified file
+            self.dot_receiver = field_expr
+                .expr()
+                .map(|e| e.syntax().text_range())
+                .and_then(|r| find_node_with_range(original_file, r));
+            self.dot_receiver_is_ambiguous_float_literal =
+                if let Some(ast::Expr::Literal(l)) = &self.dot_receiver {
+                    match l.kind() {
+                        ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
+                        _ => false,
+                    }
+                } else {
+                    false
+                }
+        }
+        if let Some(method_call_expr) = ast::MethodCallExpr::cast(parent) {
+            // As above
+            self.dot_receiver = method_call_expr
+                .expr()
+                .map(|e| e.syntax().text_range())
+                .and_then(|r| find_node_with_range(original_file, r));
+            self.is_call = true;
+        }
+    }
+}
+
+fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
+    find_covering_element(syntax, range).ancestors().find_map(N::cast)
+}
+
+fn is_node<N: AstNode>(node: &SyntaxNode) -> bool {
+    match node.ancestors().find_map(N::cast) {
+        None => false,
+        Some(n) => n.syntax().text_range() == node.text_range(),
+    }
+}
diff --git a/crates/ide/src/completion/completion_item.rs b/crates/ide/src/completion/completion_item.rs
new file mode 100644
index 000000000..9377cdc57
--- /dev/null
+++ b/crates/ide/src/completion/completion_item.rs
@@ -0,0 +1,384 @@
+//! FIXME: write short doc here
+
+use std::fmt;
+
+use hir::Documentation;
+use syntax::TextRange;
+use text_edit::TextEdit;
+
+use crate::completion::completion_config::SnippetCap;
+
+/// `CompletionItem` describes a single completion variant in the editor pop-up.
+/// It is basically a POD with various properties. To construct a
+/// `CompletionItem`, use `new` method and the `Builder` struct.
+pub struct CompletionItem {
+    /// Used only internally in tests, to check only specific kind of
+    /// completion (postfix, keyword, reference, etc).
+    #[allow(unused)]
+    pub(crate) completion_kind: CompletionKind,
+    /// Label in the completion pop up which identifies completion.
+    label: String,
+    /// Range of identifier that is being completed.
+    ///
+    /// It should be used primarily for UI, but we also use this to convert
+    /// genetic TextEdit into LSP's completion edit (see conv.rs).
+    ///
+    /// `source_range` must contain the completion offset. `insert_text` should
+    /// start with what `source_range` points to, or VSCode will filter out the
+    /// completion silently.
+    source_range: TextRange,
+    /// What happens when user selects this item.
+    ///
+    /// Typically, replaces `source_range` with new identifier.
+    text_edit: TextEdit,
+    insert_text_format: InsertTextFormat,
+
+    /// What item (struct, function, etc) are we completing.
+    kind: Option<CompletionItemKind>,
+
+    /// Lookup is used to check if completion item indeed can complete current
+    /// ident.
+    ///
+    /// That is, in `foo.bar<|>` lookup of `abracadabra` will be accepted (it
+    /// contains `bar` sub sequence), and `quux` will rejected.
+    lookup: Option<String>,
+
+    /// Additional info to show in the UI pop up.
+    detail: Option<String>,
+    documentation: Option<Documentation>,
+
+    /// Whether this item is marked as deprecated
+    deprecated: bool,
+
+    /// If completing a function call, ask the editor to show parameter popup
+    /// after completion.
+    trigger_call_info: bool,
+
+    /// Score is useful to pre select or display in better order completion items
+    score: Option<CompletionScore>,
+}
+
+// We use custom debug for CompletionItem to make snapshot tests more readable.
+impl fmt::Debug for CompletionItem {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut s = f.debug_struct("CompletionItem");
+        s.field("label", &self.label()).field("source_range", &self.source_range());
+        if self.text_edit().len() == 1 {
+            let atom = &self.text_edit().iter().next().unwrap();
+            s.field("delete", &atom.delete);
+            s.field("insert", &atom.insert);
+        } else {
+            s.field("text_edit", &self.text_edit);
+        }
+        if let Some(kind) = self.kind().as_ref() {
+            s.field("kind", kind);
+        }
+        if self.lookup() != self.label() {
+            s.field("lookup", &self.lookup());
+        }
+        if let Some(detail) = self.detail() {
+            s.field("detail", &detail);
+        }
+        if let Some(documentation) = self.documentation() {
+            s.field("documentation", &documentation);
+        }
+        if self.deprecated {
+            s.field("deprecated", &true);
+        }
+        if let Some(score) = &self.score {
+            s.field("score", score);
+        }
+        if self.trigger_call_info {
+            s.field("trigger_call_info", &true);
+        }
+        s.finish()
+    }
+}
+
+#[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq)]
+pub enum CompletionScore {
+    /// If only type match
+    TypeMatch,
+    /// If type and name match
+    TypeAndNameMatch,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CompletionItemKind {
+    Snippet,
+    Keyword,
+    Module,
+    Function,
+    BuiltinType,
+    Struct,
+    Enum,
+    EnumVariant,
+    Binding,
+    Field,
+    Static,
+    Const,
+    Trait,
+    TypeAlias,
+    Method,
+    TypeParam,
+    Macro,
+    Attribute,
+    UnresolvedReference,
+}
+
+impl CompletionItemKind {
+    #[cfg(test)]
+    pub(crate) fn tag(&self) -> &'static str {
+        match self {
+            CompletionItemKind::Attribute => "at",
+            CompletionItemKind::Binding => "bn",
+            CompletionItemKind::BuiltinType => "bt",
+            CompletionItemKind::Const => "ct",
+            CompletionItemKind::Enum => "en",
+            CompletionItemKind::EnumVariant => "ev",
+            CompletionItemKind::Field => "fd",
+            CompletionItemKind::Function => "fn",
+            CompletionItemKind::Keyword => "kw",
+            CompletionItemKind::Macro => "ma",
+            CompletionItemKind::Method => "me",
+            CompletionItemKind::Module => "md",
+            CompletionItemKind::Snippet => "sn",
+            CompletionItemKind::Static => "sc",
+            CompletionItemKind::Struct => "st",
+            CompletionItemKind::Trait => "tt",
+            CompletionItemKind::TypeAlias => "ta",
+            CompletionItemKind::TypeParam => "tp",
+            CompletionItemKind::UnresolvedReference => "??",
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+pub(crate) enum CompletionKind {
+    /// Parser-based keyword completion.
+    Keyword,
+    /// Your usual "complete all valid identifiers".
+    Reference,
+    /// "Secret sauce" completions.
+    Magic,
+    Snippet,
+    Postfix,
+    BuiltinType,
+    Attribute,
+}
+
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+pub enum InsertTextFormat {
+    PlainText,
+    Snippet,
+}
+
+impl CompletionItem {
+    pub(crate) fn new(
+        completion_kind: CompletionKind,
+        source_range: TextRange,
+        label: impl Into<String>,
+    ) -> Builder {
+        let label = label.into();
+        Builder {
+            source_range,
+            completion_kind,
+            label,
+            insert_text: None,
+            insert_text_format: InsertTextFormat::PlainText,
+            detail: None,
+            documentation: None,
+            lookup: None,
+            kind: None,
+            text_edit: None,
+            deprecated: None,
+            trigger_call_info: None,
+            score: None,
+        }
+    }
+    /// What user sees in pop-up in the UI.
+    pub fn label(&self) -> &str {
+        &self.label
+    }
+    pub fn source_range(&self) -> TextRange {
+        self.source_range
+    }
+
+    pub fn insert_text_format(&self) -> InsertTextFormat {
+        self.insert_text_format
+    }
+
+    pub fn text_edit(&self) -> &TextEdit {
+        &self.text_edit
+    }
+
+    /// Short one-line additional information, like a type
+    pub fn detail(&self) -> Option<&str> {
+        self.detail.as_deref()
+    }
+    /// A doc-comment
+    pub fn documentation(&self) -> Option<Documentation> {
+        self.documentation.clone()
+    }
+    /// What string is used for filtering.
+    pub fn lookup(&self) -> &str {
+        self.lookup.as_deref().unwrap_or(&self.label)
+    }
+
+    pub fn kind(&self) -> Option<CompletionItemKind> {
+        self.kind
+    }
+
+    pub fn deprecated(&self) -> bool {
+        self.deprecated
+    }
+
+    pub fn score(&self) -> Option<CompletionScore> {
+        self.score
+    }
+
+    pub fn trigger_call_info(&self) -> bool {
+        self.trigger_call_info
+    }
+}
+
+/// A helper to make `CompletionItem`s.
+#[must_use]
+pub(crate) struct Builder {
+    source_range: TextRange,
+    completion_kind: CompletionKind,
+    label: String,
+    insert_text: Option<String>,
+    insert_text_format: InsertTextFormat,
+    detail: Option<String>,
+    documentation: Option<Documentation>,
+    lookup: Option<String>,
+    kind: Option<CompletionItemKind>,
+    text_edit: Option<TextEdit>,
+    deprecated: Option<bool>,
+    trigger_call_info: Option<bool>,
+    score: Option<CompletionScore>,
+}
+
+impl Builder {
+    pub(crate) fn add_to(self, acc: &mut Completions) {
+        acc.add(self.build())
+    }
+
+    pub(crate) fn build(self) -> CompletionItem {
+        let label = self.label;
+        let text_edit = match self.text_edit {
+            Some(it) => it,
+            None => TextEdit::replace(
+                self.source_range,
+                self.insert_text.unwrap_or_else(|| label.clone()),
+            ),
+        };
+
+        CompletionItem {
+            source_range: self.source_range,
+            label,
+            insert_text_format: self.insert_text_format,
+            text_edit,
+            detail: self.detail,
+            documentation: self.documentation,
+            lookup: self.lookup,
+            kind: self.kind,
+            completion_kind: self.completion_kind,
+            deprecated: self.deprecated.unwrap_or(false),
+            trigger_call_info: self.trigger_call_info.unwrap_or(false),
+            score: self.score,
+        }
+    }
+    pub(crate) fn lookup_by(mut self, lookup: impl Into<String>) -> Builder {
+        self.lookup = Some(lookup.into());
+        self
+    }
+    pub(crate) fn label(mut self, label: impl Into<String>) -> Builder {
+        self.label = label.into();
+        self
+    }
+    pub(crate) fn insert_text(mut self, insert_text: impl Into<String>) -> Builder {
+        self.insert_text = Some(insert_text.into());
+        self
+    }
+    pub(crate) fn insert_snippet(
+        mut self,
+        _cap: SnippetCap,
+        snippet: impl Into<String>,
+    ) -> Builder {
+        self.insert_text_format = InsertTextFormat::Snippet;
+        self.insert_text(snippet)
+    }
+    pub(crate) fn kind(mut self, kind: CompletionItemKind) -> Builder {
+        self.kind = Some(kind);
+        self
+    }
+    pub(crate) fn text_edit(mut self, edit: TextEdit) -> Builder {
+        self.text_edit = Some(edit);
+        self
+    }
+    pub(crate) fn snippet_edit(mut self, _cap: SnippetCap, edit: TextEdit) -> Builder {
+        self.insert_text_format = InsertTextFormat::Snippet;
+        self.text_edit(edit)
+    }
+    #[allow(unused)]
+    pub(crate) fn detail(self, detail: impl Into<String>) -> Builder {
+        self.set_detail(Some(detail))
+    }
+    pub(crate) fn set_detail(mut self, detail: Option<impl Into<String>>) -> Builder {
+        self.detail = detail.map(Into::into);
+        self
+    }
+    #[allow(unused)]
+    pub(crate) fn documentation(self, docs: Documentation) -> Builder {
+        self.set_documentation(Some(docs))
+    }
+    pub(crate) fn set_documentation(mut self, docs: Option<Documentation>) -> Builder {
+        self.documentation = docs.map(Into::into);
+        self
+    }
+    pub(crate) fn set_deprecated(mut self, deprecated: bool) -> Builder {
+        self.deprecated = Some(deprecated);
+        self
+    }
+    pub(crate) fn set_score(mut self, score: CompletionScore) -> Builder {
+        self.score = Some(score);
+        self
+    }
+    pub(crate) fn trigger_call_info(mut self) -> Builder {
+        self.trigger_call_info = Some(true);
+        self
+    }
+}
+
+impl<'a> Into<CompletionItem> for Builder {
+    fn into(self) -> CompletionItem {
+        self.build()
+    }
+}
+
+/// Represents an in-progress set of completions being built.
+#[derive(Debug, Default)]
+pub(crate) struct Completions {
+    buf: Vec<CompletionItem>,
+}
+
+impl Completions {
+    pub(crate) fn add(&mut self, item: impl Into<CompletionItem>) {
+        self.buf.push(item.into())
+    }
+    pub(crate) fn add_all<I>(&mut self, items: I)
+    where
+        I: IntoIterator,
+        I::Item: Into<CompletionItem>,
+    {
+        items.into_iter().for_each(|item| self.add(item.into()))
+    }
+}
+
+impl Into<Vec<CompletionItem>> for Completions {
+    fn into(self) -> Vec<CompletionItem> {
+        self.buf
+    }
+}
diff --git a/crates/ide/src/completion/patterns.rs b/crates/ide/src/completion/patterns.rs
new file mode 100644
index 000000000..ffc97c076
--- /dev/null
+++ b/crates/ide/src/completion/patterns.rs
@@ -0,0 +1,194 @@
+//! Patterns telling us certain facts about current syntax element, they are used in completion context
+
+use syntax::{
+    algo::non_trivia_sibling,
+    ast::{self, LoopBodyOwner},
+    match_ast, AstNode, Direction, NodeOrToken, SyntaxElement,
+    SyntaxKind::*,
+    SyntaxNode, SyntaxToken,
+};
+
+#[cfg(test)]
+use crate::completion::test_utils::check_pattern_is_applicable;
+
+pub(crate) fn has_trait_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == ASSOC_ITEM_LIST)
+        .and_then(|it| it.parent())
+        .filter(|it| it.kind() == TRAIT)
+        .is_some()
+}
+#[test]
+fn test_has_trait_parent() {
+    check_pattern_is_applicable(r"trait A { f<|> }", has_trait_parent);
+}
+
+pub(crate) fn has_impl_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == ASSOC_ITEM_LIST)
+        .and_then(|it| it.parent())
+        .filter(|it| it.kind() == IMPL)
+        .is_some()
+}
+#[test]
+fn test_has_impl_parent() {
+    check_pattern_is_applicable(r"impl A { f<|> }", has_impl_parent);
+}
+
+pub(crate) fn has_block_expr_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element).filter(|it| it.kind() == BLOCK_EXPR).is_some()
+}
+#[test]
+fn test_has_block_expr_parent() {
+    check_pattern_is_applicable(r"fn my_fn() { let a = 2; f<|> }", has_block_expr_parent);
+}
+
+pub(crate) fn has_bind_pat_parent(element: SyntaxElement) -> bool {
+    element.ancestors().find(|it| it.kind() == IDENT_PAT).is_some()
+}
+#[test]
+fn test_has_bind_pat_parent() {
+    check_pattern_is_applicable(r"fn my_fn(m<|>) {}", has_bind_pat_parent);
+    check_pattern_is_applicable(r"fn my_fn() { let m<|> }", has_bind_pat_parent);
+}
+
+pub(crate) fn has_ref_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == REF_PAT || it.kind() == REF_EXPR)
+        .is_some()
+}
+#[test]
+fn test_has_ref_parent() {
+    check_pattern_is_applicable(r"fn my_fn(&m<|>) {}", has_ref_parent);
+    check_pattern_is_applicable(r"fn my() { let &m<|> }", has_ref_parent);
+}
+
+pub(crate) fn has_item_list_or_source_file_parent(element: SyntaxElement) -> bool {
+    let ancestor = not_same_range_ancestor(element);
+    if !ancestor.is_some() {
+        return true;
+    }
+    ancestor.filter(|it| it.kind() == SOURCE_FILE || it.kind() == ITEM_LIST).is_some()
+}
+#[test]
+fn test_has_item_list_or_source_file_parent() {
+    check_pattern_is_applicable(r"i<|>", has_item_list_or_source_file_parent);
+    check_pattern_is_applicable(r"mod foo { f<|> }", has_item_list_or_source_file_parent);
+}
+
+pub(crate) fn is_match_arm(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element.clone()).filter(|it| it.kind() == MATCH_ARM).is_some()
+        && previous_sibling_or_ancestor_sibling(element)
+            .and_then(|it| it.into_token())
+            .filter(|it| it.kind() == FAT_ARROW)
+            .is_some()
+}
+#[test]
+fn test_is_match_arm() {
+    check_pattern_is_applicable(r"fn my_fn() { match () { () => m<|> } }", is_match_arm);
+}
+
+pub(crate) fn unsafe_is_prev(element: SyntaxElement) -> bool {
+    element
+        .into_token()
+        .and_then(|it| previous_non_trivia_token(it))
+        .filter(|it| it.kind() == UNSAFE_KW)
+        .is_some()
+}
+#[test]
+fn test_unsafe_is_prev() {
+    check_pattern_is_applicable(r"unsafe i<|>", unsafe_is_prev);
+}
+
+pub(crate) fn if_is_prev(element: SyntaxElement) -> bool {
+    element
+        .into_token()
+        .and_then(|it| previous_non_trivia_token(it))
+        .filter(|it| it.kind() == IF_KW)
+        .is_some()
+}
+#[test]
+fn test_if_is_prev() {
+    check_pattern_is_applicable(r"if l<|>", if_is_prev);
+}
+
+pub(crate) fn has_trait_as_prev_sibling(element: SyntaxElement) -> bool {
+    previous_sibling_or_ancestor_sibling(element).filter(|it| it.kind() == TRAIT).is_some()
+}
+#[test]
+fn test_has_trait_as_prev_sibling() {
+    check_pattern_is_applicable(r"trait A w<|> {}", has_trait_as_prev_sibling);
+}
+
+pub(crate) fn has_impl_as_prev_sibling(element: SyntaxElement) -> bool {
+    previous_sibling_or_ancestor_sibling(element).filter(|it| it.kind() == IMPL).is_some()
+}
+#[test]
+fn test_has_impl_as_prev_sibling() {
+    check_pattern_is_applicable(r"impl A w<|> {}", has_impl_as_prev_sibling);
+}
+
+pub(crate) fn is_in_loop_body(element: SyntaxElement) -> bool {
+    let leaf = match element {
+        NodeOrToken::Node(node) => node,
+        NodeOrToken::Token(token) => token.parent(),
+    };
+    for node in leaf.ancestors() {
+        if node.kind() == FN || node.kind() == CLOSURE_EXPR {
+            break;
+        }
+        let loop_body = match_ast! {
+            match node {
+                ast::ForExpr(it) => it.loop_body(),
+                ast::WhileExpr(it) => it.loop_body(),
+                ast::LoopExpr(it) => it.loop_body(),
+                _ => None,
+            }
+        };
+        if let Some(body) = loop_body {
+            if body.syntax().text_range().contains_range(leaf.text_range()) {
+                return true;
+            }
+        }
+    }
+    false
+}
+
+fn not_same_range_ancestor(element: SyntaxElement) -> Option<SyntaxNode> {
+    element
+        .ancestors()
+        .take_while(|it| it.text_range() == element.text_range())
+        .last()
+        .and_then(|it| it.parent())
+}
+
+fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
+    let mut token = token.prev_token();
+    while let Some(inner) = token.clone() {
+        if !inner.kind().is_trivia() {
+            return Some(inner);
+        } else {
+            token = inner.prev_token();
+        }
+    }
+    None
+}
+
+fn previous_sibling_or_ancestor_sibling(element: SyntaxElement) -> Option<SyntaxElement> {
+    let token_sibling = non_trivia_sibling(element.clone(), Direction::Prev);
+    if let Some(sibling) = token_sibling {
+        Some(sibling)
+    } else {
+        // if not trying to find first ancestor which has such a sibling
+        let node = match element {
+            NodeOrToken::Node(node) => node,
+            NodeOrToken::Token(token) => token.parent(),
+        };
+        let range = node.text_range();
+        let top_node = node.ancestors().take_while(|it| it.text_range() == range).last()?;
+        let prev_sibling_node = top_node.ancestors().find(|it| {
+            non_trivia_sibling(NodeOrToken::Node(it.to_owned()), Direction::Prev).is_some()
+        })?;
+        non_trivia_sibling(NodeOrToken::Node(prev_sibling_node), Direction::Prev)
+    }
+}
diff --git a/crates/ide/src/completion/presentation.rs b/crates/ide/src/completion/presentation.rs
new file mode 100644
index 000000000..e1b1ea4ce
--- /dev/null
+++ b/crates/ide/src/completion/presentation.rs
@@ -0,0 +1,1229 @@
+//! This modules takes care of rendering various definitions as completion items.
+//! It also handles scoring (sorting) completions.
+
+use hir::{Docs, HasAttrs, HasSource, HirDisplay, ModPath, ScopeDef, StructKind, Type};
+use itertools::Itertools;
+use syntax::ast::NameOwner;
+use test_utils::mark;
+
+use crate::{
+    completion::{
+        completion_item::Builder, CompletionContext, CompletionItem, CompletionItemKind,
+        CompletionKind, Completions,
+    },
+    display::{const_label, function_declaration, macro_label, type_label},
+    CompletionScore, RootDatabase,
+};
+
+impl Completions {
+    pub(crate) fn add_field(&mut self, ctx: &CompletionContext, field: hir::Field, ty: &Type) {
+        let is_deprecated = is_deprecated(field, ctx.db);
+        let name = field.name(ctx.db);
+        let mut completion_item =
+            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.to_string())
+                .kind(CompletionItemKind::Field)
+                .detail(ty.display(ctx.db).to_string())
+                .set_documentation(field.docs(ctx.db))
+                .set_deprecated(is_deprecated);
+
+        if let Some(score) = compute_score(ctx, &ty, &name.to_string()) {
+            completion_item = completion_item.set_score(score);
+        }
+
+        completion_item.add_to(self);
+    }
+
+    pub(crate) fn add_tuple_field(&mut self, ctx: &CompletionContext, field: usize, ty: &Type) {
+        CompletionItem::new(CompletionKind::Reference, ctx.source_range(), field.to_string())
+            .kind(CompletionItemKind::Field)
+            .detail(ty.display(ctx.db).to_string())
+            .add_to(self);
+    }
+
+    pub(crate) fn add_resolution(
+        &mut self,
+        ctx: &CompletionContext,
+        local_name: String,
+        resolution: &ScopeDef,
+    ) {
+        use hir::ModuleDef::*;
+
+        let completion_kind = match resolution {
+            ScopeDef::ModuleDef(BuiltinType(..)) => CompletionKind::BuiltinType,
+            _ => CompletionKind::Reference,
+        };
+
+        let kind = match resolution {
+            ScopeDef::ModuleDef(Module(..)) => CompletionItemKind::Module,
+            ScopeDef::ModuleDef(Function(func)) => {
+                return self.add_function(ctx, *func, Some(local_name));
+            }
+            ScopeDef::ModuleDef(Adt(hir::Adt::Struct(_))) => CompletionItemKind::Struct,
+            // FIXME: add CompletionItemKind::Union
+            ScopeDef::ModuleDef(Adt(hir::Adt::Union(_))) => CompletionItemKind::Struct,
+            ScopeDef::ModuleDef(Adt(hir::Adt::Enum(_))) => CompletionItemKind::Enum,
+
+            ScopeDef::ModuleDef(EnumVariant(var)) => {
+                return self.add_enum_variant(ctx, *var, Some(local_name));
+            }
+            ScopeDef::ModuleDef(Const(..)) => CompletionItemKind::Const,
+            ScopeDef::ModuleDef(Static(..)) => CompletionItemKind::Static,
+            ScopeDef::ModuleDef(Trait(..)) => CompletionItemKind::Trait,
+            ScopeDef::ModuleDef(TypeAlias(..)) => CompletionItemKind::TypeAlias,
+            ScopeDef::ModuleDef(BuiltinType(..)) => CompletionItemKind::BuiltinType,
+            ScopeDef::GenericParam(..) => CompletionItemKind::TypeParam,
+            ScopeDef::Local(..) => CompletionItemKind::Binding,
+            // (does this need its own kind?)
+            ScopeDef::AdtSelfType(..) | ScopeDef::ImplSelfType(..) => CompletionItemKind::TypeParam,
+            ScopeDef::MacroDef(mac) => {
+                return self.add_macro(ctx, Some(local_name), *mac);
+            }
+            ScopeDef::Unknown => {
+                return self.add(
+                    CompletionItem::new(CompletionKind::Reference, ctx.source_range(), local_name)
+                        .kind(CompletionItemKind::UnresolvedReference),
+                );
+            }
+        };
+
+        let docs = match resolution {
+            ScopeDef::ModuleDef(Module(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Adt(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(EnumVariant(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Const(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Static(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Trait(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(TypeAlias(it)) => it.docs(ctx.db),
+            _ => None,
+        };
+
+        let mut completion_item =
+            CompletionItem::new(completion_kind, ctx.source_range(), local_name.clone());
+        if let ScopeDef::Local(local) = resolution {
+            let ty = local.ty(ctx.db);
+            if !ty.is_unknown() {
+                completion_item = completion_item.detail(ty.display(ctx.db).to_string());
+            }
+        };
+
+        if let ScopeDef::Local(local) = resolution {
+            if let Some(score) = compute_score(ctx, &local.ty(ctx.db), &local_name) {
+                completion_item = completion_item.set_score(score);
+            }
+        }
+
+        // Add `<>` for generic types
+        if ctx.is_path_type && !ctx.has_type_args && ctx.config.add_call_parenthesis {
+            if let Some(cap) = ctx.config.snippet_cap {
+                let has_non_default_type_params = match resolution {
+                    ScopeDef::ModuleDef(Adt(it)) => it.has_non_default_type_params(ctx.db),
+                    ScopeDef::ModuleDef(TypeAlias(it)) => it.has_non_default_type_params(ctx.db),
+                    _ => false,
+                };
+                if has_non_default_type_params {
+                    mark::hit!(inserts_angle_brackets_for_generics);
+                    completion_item = completion_item
+                        .lookup_by(local_name.clone())
+                        .label(format!("{}<…>", local_name))
+                        .insert_snippet(cap, format!("{}<$0>", local_name));
+                }
+            }
+        }
+
+        completion_item.kind(kind).set_documentation(docs).add_to(self)
+    }
+
+    pub(crate) fn add_macro(
+        &mut self,
+        ctx: &CompletionContext,
+        name: Option<String>,
+        macro_: hir::MacroDef,
+    ) {
+        // FIXME: Currently proc-macro do not have ast-node,
+        // such that it does not have source
+        if macro_.is_proc_macro() {
+            return;
+        }
+
+        let name = match name {
+            Some(it) => it,
+            None => return,
+        };
+
+        let ast_node = macro_.source(ctx.db).value;
+        let detail = macro_label(&ast_node);
+
+        let docs = macro_.docs(ctx.db);
+
+        let mut builder = CompletionItem::new(
+            CompletionKind::Reference,
+            ctx.source_range(),
+            &format!("{}!", name),
+        )
+        .kind(CompletionItemKind::Macro)
+        .set_documentation(docs.clone())
+        .set_deprecated(is_deprecated(macro_, ctx.db))
+        .detail(detail);
+
+        let needs_bang = ctx.use_item_syntax.is_none() && !ctx.is_macro_call;
+        builder = match ctx.config.snippet_cap {
+            Some(cap) if needs_bang => {
+                let docs = docs.as_ref().map_or("", |s| s.as_str());
+                let (bra, ket) = guess_macro_braces(&name, docs);
+                builder
+                    .insert_snippet(cap, format!("{}!{}$0{}", name, bra, ket))
+                    .label(format!("{}!{}…{}", name, bra, ket))
+                    .lookup_by(format!("{}!", name))
+            }
+            None if needs_bang => builder.insert_text(format!("{}!", name)),
+            _ => {
+                mark::hit!(dont_insert_macro_call_parens_unncessary);
+                builder.insert_text(name)
+            }
+        };
+
+        self.add(builder);
+    }
+
+    pub(crate) fn add_function(
+        &mut self,
+        ctx: &CompletionContext,
+        func: hir::Function,
+        local_name: Option<String>,
+    ) {
+        let has_self_param = func.has_self_param(ctx.db);
+
+        let name = local_name.unwrap_or_else(|| func.name(ctx.db).to_string());
+        let ast_node = func.source(ctx.db).value;
+
+        let mut builder =
+            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.clone())
+                .kind(if has_self_param {
+                    CompletionItemKind::Method
+                } else {
+                    CompletionItemKind::Function
+                })
+                .set_documentation(func.docs(ctx.db))
+                .set_deprecated(is_deprecated(func, ctx.db))
+                .detail(function_declaration(&ast_node));
+
+        let params = ast_node
+            .param_list()
+            .into_iter()
+            .flat_map(|it| it.params())
+            .flat_map(|it| it.pat())
+            .map(|pat| pat.to_string().trim_start_matches('_').into())
+            .collect();
+
+        builder = builder.add_call_parens(ctx, name, Params::Named(params));
+
+        self.add(builder)
+    }
+
+    pub(crate) fn add_const(&mut self, ctx: &CompletionContext, constant: hir::Const) {
+        let ast_node = constant.source(ctx.db).value;
+        let name = match ast_node.name() {
+            Some(name) => name,
+            _ => return,
+        };
+        let detail = const_label(&ast_node);
+
+        CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.text().to_string())
+            .kind(CompletionItemKind::Const)
+            .set_documentation(constant.docs(ctx.db))
+            .set_deprecated(is_deprecated(constant, ctx.db))
+            .detail(detail)
+            .add_to(self);
+    }
+
+    pub(crate) fn add_type_alias(&mut self, ctx: &CompletionContext, type_alias: hir::TypeAlias) {
+        let type_def = type_alias.source(ctx.db).value;
+        let name = match type_def.name() {
+            Some(name) => name,
+            _ => return,
+        };
+        let detail = type_label(&type_def);
+
+        CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.text().to_string())
+            .kind(CompletionItemKind::TypeAlias)
+            .set_documentation(type_alias.docs(ctx.db))
+            .set_deprecated(is_deprecated(type_alias, ctx.db))
+            .detail(detail)
+            .add_to(self);
+    }
+
+    pub(crate) fn add_qualified_enum_variant(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::EnumVariant,
+        path: ModPath,
+    ) {
+        self.add_enum_variant_impl(ctx, variant, None, Some(path))
+    }
+
+    pub(crate) fn add_enum_variant(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::EnumVariant,
+        local_name: Option<String>,
+    ) {
+        self.add_enum_variant_impl(ctx, variant, local_name, None)
+    }
+
+    fn add_enum_variant_impl(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::EnumVariant,
+        local_name: Option<String>,
+        path: Option<ModPath>,
+    ) {
+        let is_deprecated = is_deprecated(variant, ctx.db);
+        let name = local_name.unwrap_or_else(|| variant.name(ctx.db).to_string());
+        let qualified_name = match &path {
+            Some(it) => it.to_string(),
+            None => name.to_string(),
+        };
+        let detail_types = variant
+            .fields(ctx.db)
+            .into_iter()
+            .map(|field| (field.name(ctx.db), field.signature_ty(ctx.db)));
+        let variant_kind = variant.kind(ctx.db);
+        let detail = match variant_kind {
+            StructKind::Tuple | StructKind::Unit => format!(
+                "({})",
+                detail_types.map(|(_, t)| t.display(ctx.db).to_string()).format(", ")
+            ),
+            StructKind::Record => format!(
+                "{{ {} }}",
+                detail_types
+                    .map(|(n, t)| format!("{}: {}", n, t.display(ctx.db).to_string()))
+                    .format(", ")
+            ),
+        };
+        let mut res = CompletionItem::new(
+            CompletionKind::Reference,
+            ctx.source_range(),
+            qualified_name.clone(),
+        )
+        .kind(CompletionItemKind::EnumVariant)
+        .set_documentation(variant.docs(ctx.db))
+        .set_deprecated(is_deprecated)
+        .detail(detail);
+
+        if path.is_some() {
+            res = res.lookup_by(name);
+        }
+
+        if variant_kind == StructKind::Tuple {
+            mark::hit!(inserts_parens_for_tuple_enums);
+            let params = Params::Anonymous(variant.fields(ctx.db).len());
+            res = res.add_call_parens(ctx, qualified_name, params)
+        }
+
+        res.add_to(self);
+    }
+}
+
+pub(crate) fn compute_score(
+    ctx: &CompletionContext,
+    ty: &Type,
+    name: &str,
+) -> Option<CompletionScore> {
+    let (active_name, active_type) = if let Some(record_field) = &ctx.record_field_syntax {
+        mark::hit!(record_field_type_match);
+        let (struct_field, _local) = ctx.sema.resolve_record_field(record_field)?;
+        (struct_field.name(ctx.db).to_string(), struct_field.signature_ty(ctx.db))
+    } else if let Some(active_parameter) = &ctx.active_parameter {
+        mark::hit!(active_param_type_match);
+        (active_parameter.name.clone(), active_parameter.ty.clone())
+    } else {
+        return None;
+    };
+
+    // Compute score
+    // For the same type
+    if &active_type != ty {
+        return None;
+    }
+
+    let mut res = CompletionScore::TypeMatch;
+
+    // If same type + same name then go top position
+    if active_name == name {
+        res = CompletionScore::TypeAndNameMatch
+    }
+
+    Some(res)
+}
+
+enum Params {
+    Named(Vec<String>),
+    Anonymous(usize),
+}
+
+impl Params {
+    fn len(&self) -> usize {
+        match self {
+            Params::Named(xs) => xs.len(),
+            Params::Anonymous(len) => *len,
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+impl Builder {
+    fn add_call_parens(mut self, ctx: &CompletionContext, name: String, params: Params) -> Builder {
+        if !ctx.config.add_call_parenthesis {
+            return self;
+        }
+        if ctx.use_item_syntax.is_some() {
+            mark::hit!(no_parens_in_use_item);
+            return self;
+        }
+        if ctx.is_pattern_call {
+            mark::hit!(dont_duplicate_pattern_parens);
+            return self;
+        }
+        if ctx.is_call {
+            return self;
+        }
+
+        // Don't add parentheses if the expected type is some function reference.
+        if let Some(ty) = &ctx.expected_type {
+            if ty.is_fn() {
+                mark::hit!(no_call_parens_if_fn_ptr_needed);
+                return self;
+            }
+        }
+
+        let cap = match ctx.config.snippet_cap {
+            Some(it) => it,
+            None => return self,
+        };
+        // If not an import, add parenthesis automatically.
+        mark::hit!(inserts_parens_for_function_calls);
+
+        let (snippet, label) = if params.is_empty() {
+            (format!("{}()$0", name), format!("{}()", name))
+        } else {
+            self = self.trigger_call_info();
+            let snippet = match (ctx.config.add_call_argument_snippets, params) {
+                (true, Params::Named(params)) => {
+                    let function_params_snippet =
+                        params.iter().enumerate().format_with(", ", |(index, param_name), f| {
+                            f(&format_args!("${{{}:{}}}", index + 1, param_name))
+                        });
+                    format!("{}({})$0", name, function_params_snippet)
+                }
+                _ => {
+                    mark::hit!(suppress_arg_snippets);
+                    format!("{}($0)", name)
+                }
+            };
+
+            (snippet, format!("{}(…)", name))
+        };
+        self.lookup_by(name).label(label).insert_snippet(cap, snippet)
+    }
+}
+
+fn is_deprecated(node: impl HasAttrs, db: &RootDatabase) -> bool {
+    node.attrs(db).by_key("deprecated").exists()
+}
+
+fn guess_macro_braces(macro_name: &str, docs: &str) -> (&'static str, &'static str) {
+    let mut votes = [0, 0, 0];
+    for (idx, s) in docs.match_indices(&macro_name) {
+        let (before, after) = (&docs[..idx], &docs[idx + s.len()..]);
+        // Ensure to match the full word
+        if after.starts_with('!')
+            && !before.ends_with(|c: char| c == '_' || c.is_ascii_alphanumeric())
+        {
+            // It may have spaces before the braces like `foo! {}`
+            match after[1..].chars().find(|&c| !c.is_whitespace()) {
+                Some('{') => votes[0] += 1,
+                Some('[') => votes[1] += 1,
+                Some('(') => votes[2] += 1,
+                _ => {}
+            }
+        }
+    }
+
+    // Insert a space before `{}`.
+    // We prefer the last one when some votes equal.
+    let (_vote, (bra, ket)) = votes
+        .iter()
+        .zip(&[(" {", "}"), ("[", "]"), ("(", ")")])
+        .max_by_key(|&(&vote, _)| vote)
+        .unwrap();
+    (*bra, *ket)
+}
+
+#[cfg(test)]
+mod tests {
+    use std::cmp::Reverse;
+
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::{
+        completion::{
+            test_utils::{
+                check_edit, check_edit_with_config, do_completion, get_all_completion_items,
+            },
+            CompletionConfig, CompletionKind,
+        },
+        CompletionScore,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = do_completion(ra_fixture, CompletionKind::Reference);
+        expect.assert_debug_eq(&actual);
+    }
+
+    fn check_scores(ra_fixture: &str, expect: Expect) {
+        fn display_score(score: Option<CompletionScore>) -> &'static str {
+            match score {
+                Some(CompletionScore::TypeMatch) => "[type]",
+                Some(CompletionScore::TypeAndNameMatch) => "[type+name]",
+                None => "[]".into(),
+            }
+        }
+
+        let mut completions = get_all_completion_items(CompletionConfig::default(), ra_fixture);
+        completions.sort_by_key(|it| (Reverse(it.score()), it.label().to_string()));
+        let actual = completions
+            .into_iter()
+            .filter(|it| it.completion_kind == CompletionKind::Reference)
+            .map(|it| {
+                let tag = it.kind().unwrap().tag();
+                let score = display_score(it.score());
+                format!("{} {} {}\n", tag, it.label(), score)
+            })
+            .collect::<String>();
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn enum_detail_includes_record_fields() {
+        check(
+            r#"
+enum Foo { Foo { x: i32, y: i32 } }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo",
+                        source_range: 54..56,
+                        delete: 54..56,
+                        insert: "Foo",
+                        kind: EnumVariant,
+                        detail: "{ x: i32, y: i32 }",
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn enum_detail_doesnt_include_tuple_fields() {
+        check(
+            r#"
+enum Foo { Foo (i32, i32) }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo(…)",
+                        source_range: 46..48,
+                        delete: 46..48,
+                        insert: "Foo($0)",
+                        kind: EnumVariant,
+                        lookup: "Foo",
+                        detail: "(i32, i32)",
+                        trigger_call_info: true,
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn enum_detail_just_parentheses_for_unit() {
+        check(
+            r#"
+enum Foo { Foo }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo",
+                        source_range: 35..37,
+                        delete: 35..37,
+                        insert: "Foo",
+                        kind: EnumVariant,
+                        detail: "()",
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn sets_deprecated_flag_in_completion_items() {
+        check(
+            r#"
+#[deprecated]
+fn something_deprecated() {}
+#[deprecated(since = "1.0.0")]
+fn something_else_deprecated() {}
+
+fn main() { som<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "main()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "main()$0",
+                        kind: Function,
+                        lookup: "main",
+                        detail: "fn main()",
+                    },
+                    CompletionItem {
+                        label: "something_deprecated()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "something_deprecated()$0",
+                        kind: Function,
+                        lookup: "something_deprecated",
+                        detail: "fn something_deprecated()",
+                        deprecated: true,
+                    },
+                    CompletionItem {
+                        label: "something_else_deprecated()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "something_else_deprecated()$0",
+                        kind: Function,
+                        lookup: "something_else_deprecated",
+                        detail: "fn something_else_deprecated()",
+                        deprecated: true,
+                    },
+                ]
+            "#]],
+        );
+
+        check(
+            r#"
+struct A { #[deprecated] the_field: u32 }
+fn foo() { A { the<|> } }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "the_field",
+                        source_range: 57..60,
+                        delete: 57..60,
+                        insert: "the_field",
+                        kind: Field,
+                        detail: "u32",
+                        deprecated: true,
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn renders_docs() {
+        check(
+            r#"
+struct S {
+    /// Field docs
+    foo:
+}
+impl S {
+    /// Method docs
+    fn bar(self) { self.<|> }
+}"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "bar()",
+                        source_range: 94..94,
+                        delete: 94..94,
+                        insert: "bar()$0",
+                        kind: Method,
+                        lookup: "bar",
+                        detail: "fn bar(self)",
+                        documentation: Documentation(
+                            "Method docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "foo",
+                        source_range: 94..94,
+                        delete: 94..94,
+                        insert: "foo",
+                        kind: Field,
+                        detail: "{unknown}",
+                        documentation: Documentation(
+                            "Field docs",
+                        ),
+                    },
+                ]
+            "#]],
+        );
+
+        check(
+            r#"
+use self::my<|>;
+
+/// mod docs
+mod my { }
+
+/// enum docs
+enum E {
+    /// variant docs
+    V
+}
+use self::E::*;
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "E",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "E",
+                        kind: Enum,
+                        documentation: Documentation(
+                            "enum docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "V",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "V",
+                        kind: EnumVariant,
+                        detail: "()",
+                        documentation: Documentation(
+                            "variant docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "my",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "my",
+                        kind: Module,
+                        documentation: Documentation(
+                            "mod docs",
+                        ),
+                    },
+                ]
+            "#]],
+        )
+    }
+
+    #[test]
+    fn dont_render_attrs() {
+        check(
+            r#"
+struct S;
+impl S {
+    #[inline]
+    fn the_method(&self) { }
+}
+fn foo(s: S) { s.<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "the_method()",
+                        source_range: 81..81,
+                        delete: 81..81,
+                        insert: "the_method()$0",
+                        kind: Method,
+                        lookup: "the_method",
+                        detail: "fn the_method(&self)",
+                    },
+                ]
+            "#]],
+        )
+    }
+
+    #[test]
+    fn inserts_parens_for_function_calls() {
+        mark::check!(inserts_parens_for_function_calls);
+        check_edit(
+            "no_args",
+            r#"
+fn no_args() {}
+fn main() { no_<|> }
+"#,
+            r#"
+fn no_args() {}
+fn main() { no_args()$0 }
+"#,
+        );
+
+        check_edit(
+            "with_args",
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_<|> }
+"#,
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_args(${1:x}, ${2:y})$0 }
+"#,
+        );
+
+        check_edit(
+            "foo",
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn bar(s: &S) { s.f<|> }
+"#,
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn bar(s: &S) { s.foo()$0 }
+"#,
+        );
+
+        check_edit(
+            "foo",
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {}
+}
+fn bar(s: &S) {
+    s.f<|>
+}
+"#,
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {}
+}
+fn bar(s: &S) {
+    s.foo(${1:x})$0
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn suppress_arg_snippets() {
+        mark::check!(suppress_arg_snippets);
+        check_edit_with_config(
+            CompletionConfig { add_call_argument_snippets: false, ..CompletionConfig::default() },
+            "with_args",
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_<|> }
+"#,
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_args($0) }
+"#,
+        );
+    }
+
+    #[test]
+    fn strips_underscores_from_args() {
+        check_edit(
+            "foo",
+            r#"
+fn foo(_foo: i32, ___bar: bool, ho_ge_: String) {}
+fn main() { f<|> }
+"#,
+            r#"
+fn foo(_foo: i32, ___bar: bool, ho_ge_: String) {}
+fn main() { foo(${1:foo}, ${2:bar}, ${3:ho_ge_})$0 }
+"#,
+        );
+    }
+
+    #[test]
+    fn inserts_parens_for_tuple_enums() {
+        mark::check!(inserts_parens_for_tuple_enums);
+        check_edit(
+            "Some",
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main() -> Option<i32> {
+    Som<|>
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main() -> Option<i32> {
+    Some($0)
+}
+"#,
+        );
+        check_edit(
+            "Some",
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main(value: Option<i32>) {
+    match value {
+        Som<|>
+    }
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main(value: Option<i32>) {
+    match value {
+        Some($0)
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn dont_duplicate_pattern_parens() {
+        mark::check!(dont_duplicate_pattern_parens);
+        check_edit(
+            "Var",
+            r#"
+enum E { Var(i32) }
+fn main() {
+    match E::Var(92) {
+        E::<|>(92) => (),
+    }
+}
+"#,
+            r#"
+enum E { Var(i32) }
+fn main() {
+    match E::Var(92) {
+        E::Var(92) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_call_parens_if_fn_ptr_needed() {
+        mark::check!(no_call_parens_if_fn_ptr_needed);
+        check_edit(
+            "foo",
+            r#"
+fn foo(foo: u8, bar: u8) {}
+struct ManualVtable { f: fn(u8, u8) }
+
+fn main() -> ManualVtable {
+    ManualVtable { f: f<|> }
+}
+"#,
+            r#"
+fn foo(foo: u8, bar: u8) {}
+struct ManualVtable { f: fn(u8, u8) }
+
+fn main() -> ManualVtable {
+    ManualVtable { f: foo }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_parens_in_use_item() {
+        mark::check!(no_parens_in_use_item);
+        check_edit(
+            "foo",
+            r#"
+mod m { pub fn foo() {} }
+use crate::m::f<|>;
+"#,
+            r#"
+mod m { pub fn foo() {} }
+use crate::m::foo;
+"#,
+        );
+    }
+
+    #[test]
+    fn no_parens_in_call() {
+        check_edit(
+            "foo",
+            r#"
+fn foo(x: i32) {}
+fn main() { f<|>(); }
+"#,
+            r#"
+fn foo(x: i32) {}
+fn main() { foo(); }
+"#,
+        );
+        check_edit(
+            "foo",
+            r#"
+struct Foo;
+impl Foo { fn foo(&self){} }
+fn f(foo: &Foo) { foo.f<|>(); }
+"#,
+            r#"
+struct Foo;
+impl Foo { fn foo(&self){} }
+fn f(foo: &Foo) { foo.foo(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn inserts_angle_brackets_for_generics() {
+        mark::check!(inserts_angle_brackets_for_generics);
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T> {}
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+struct Vec<T> {}
+fn foo(xs: Vec<$0>)
+"#,
+        );
+        check_edit(
+            "Vec",
+            r#"
+type Vec<T> = (T,);
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+type Vec<T> = (T,);
+fn foo(xs: Vec<$0>)
+"#,
+        );
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T = i128> {}
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+struct Vec<T = i128> {}
+fn foo(xs: Vec)
+"#,
+        );
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T> {}
+fn foo(xs: Ve<|><i128>)
+"#,
+            r#"
+struct Vec<T> {}
+fn foo(xs: Vec<i128>)
+"#,
+        );
+    }
+
+    #[test]
+    fn dont_insert_macro_call_parens_unncessary() {
+        mark::check!(dont_insert_macro_call_parens_unncessary);
+        check_edit(
+            "frobnicate!",
+            r#"
+//- /main.rs
+use foo::<|>;
+//- /foo/lib.rs
+#[macro_export]
+macro_rules frobnicate { () => () }
+"#,
+            r#"
+use foo::frobnicate;
+"#,
+        );
+
+        check_edit(
+            "frobnicate!",
+            r#"
+macro_rules frobnicate { () => () }
+fn main() { frob<|>!(); }
+"#,
+            r#"
+macro_rules frobnicate { () => () }
+fn main() { frobnicate!(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn active_param_score() {
+        mark::check!(active_param_type_match);
+        check_scores(
+            r#"
+struct S { foo: i64, bar: u32, baz: u32 }
+fn test(bar: u32) { }
+fn foo(s: S) { test(s.<|>) }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
+        );
+    }
+
+    #[test]
+    fn record_field_scores() {
+        mark::check!(record_field_type_match);
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn foo(a: A) { B { bar: a.<|> }; }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
+        )
+    }
+
+    #[test]
+    fn record_field_and_call_scores() {
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn f(foo: i64) {  }
+fn foo(a: A) { B { bar: f(a.<|>) }; }
+"#,
+            expect![[r#"
+                fd foo [type+name]
+                fd bar []
+                fd baz []
+            "#]],
+        );
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn f(foo: i64) {  }
+fn foo(a: A) { f(B { bar: a.<|> }); }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
+        );
+    }
+
+    #[test]
+    fn prioritize_exact_ref_match() {
+        check_scores(
+            r#"
+struct WorldSnapshot { _f: () };
+fn go(world: &WorldSnapshot) { go(w<|>) }
+"#,
+            expect![[r#"
+                bn world [type+name]
+                st WorldSnapshot []
+                fn go(…) []
+            "#]],
+        );
+    }
+
+    #[test]
+    fn too_many_arguments() {
+        mark::check!(too_many_arguments);
+        check_scores(
+            r#"
+struct Foo;
+fn f(foo: &Foo) { f(foo, w<|>) }
+"#,
+            expect![[r#"
+                st Foo []
+                fn f(…) []
+                bn foo []
+            "#]],
+        );
+    }
+
+    #[test]
+    fn guesses_macro_braces() {
+        check_edit(
+            "vec!",
+            r#"
+/// Creates a [`Vec`] containing the arguments.
+///
+/// ```
+/// let v = vec![1, 2, 3];
+/// assert_eq!(v[0], 1);
+/// assert_eq!(v[1], 2);
+/// assert_eq!(v[2], 3);
+/// ```
+macro_rules! vec { () => {} }
+
+fn fn main() { v<|> }
+"#,
+            r#"
+/// Creates a [`Vec`] containing the arguments.
+///
+/// ```
+/// let v = vec![1, 2, 3];
+/// assert_eq!(v[0], 1);
+/// assert_eq!(v[1], 2);
+/// assert_eq!(v[2], 3);
+/// ```
+macro_rules! vec { () => {} }
+
+fn fn main() { vec![$0] }
+"#,
+        );
+
+        check_edit(
+            "foo!",
+            r#"
+/// Foo
+///
+/// Don't call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`,
+/// call as `let _=foo!  { hello world };`
+macro_rules! foo { () => {} }
+fn main() { <|> }
+"#,
+            r#"
+/// Foo
+///
+/// Don't call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`,
+/// call as `let _=foo!  { hello world };`
+macro_rules! foo { () => {} }
+fn main() { foo! {$0} }
+"#,
+        )
+    }
+}
diff --git a/crates/ide/src/completion/test_utils.rs b/crates/ide/src/completion/test_utils.rs
new file mode 100644
index 000000000..1452d7e9e
--- /dev/null
+++ b/crates/ide/src/completion/test_utils.rs
@@ -0,0 +1,114 @@
+//! Runs completion for testing purposes.
+
+use hir::Semantics;
+use itertools::Itertools;
+use stdx::{format_to, trim_indent};
+use syntax::{AstNode, NodeOrToken, SyntaxElement};
+use test_utils::assert_eq_text;
+
+use crate::{
+    completion::{completion_item::CompletionKind, CompletionConfig},
+    mock_analysis::analysis_and_position,
+    CompletionItem,
+};
+
+pub(crate) fn do_completion(code: &str, kind: CompletionKind) -> Vec<CompletionItem> {
+    do_completion_with_config(CompletionConfig::default(), code, kind)
+}
+
+pub(crate) fn do_completion_with_config(
+    config: CompletionConfig,
+    code: &str,
+    kind: CompletionKind,
+) -> Vec<CompletionItem> {
+    let mut kind_completions: Vec<CompletionItem> = get_all_completion_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .collect();
+    kind_completions.sort_by(|l, r| l.label().cmp(r.label()));
+    kind_completions
+}
+
+pub(crate) fn completion_list(code: &str, kind: CompletionKind) -> String {
+    completion_list_with_config(CompletionConfig::default(), code, kind)
+}
+
+pub(crate) fn completion_list_with_config(
+    config: CompletionConfig,
+    code: &str,
+    kind: CompletionKind,
+) -> String {
+    let mut kind_completions: Vec<CompletionItem> = get_all_completion_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .collect();
+    kind_completions.sort_by_key(|c| c.label().to_owned());
+    let label_width = kind_completions
+        .iter()
+        .map(|it| monospace_width(it.label()))
+        .max()
+        .unwrap_or_default()
+        .min(16);
+    kind_completions
+        .into_iter()
+        .map(|it| {
+            let tag = it.kind().unwrap().tag();
+            let var_name = format!("{} {}", tag, it.label());
+            let mut buf = var_name;
+            if let Some(detail) = it.detail() {
+                let width = label_width.saturating_sub(monospace_width(it.label()));
+                format_to!(buf, "{:width$} {}", "", detail, width = width);
+            }
+            format_to!(buf, "\n");
+            buf
+        })
+        .collect()
+}
+
+fn monospace_width(s: &str) -> usize {
+    s.chars().count()
+}
+
+pub(crate) fn check_edit(what: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+    check_edit_with_config(CompletionConfig::default(), what, ra_fixture_before, ra_fixture_after)
+}
+
+pub(crate) fn check_edit_with_config(
+    config: CompletionConfig,
+    what: &str,
+    ra_fixture_before: &str,
+    ra_fixture_after: &str,
+) {
+    let ra_fixture_after = trim_indent(ra_fixture_after);
+    let (analysis, position) = analysis_and_position(ra_fixture_before);
+    let completions: Vec<CompletionItem> =
+        analysis.completions(&config, position).unwrap().unwrap().into();
+    let (completion,) = completions
+        .iter()
+        .filter(|it| it.lookup() == what)
+        .collect_tuple()
+        .unwrap_or_else(|| panic!("can't find {:?} completion in {:#?}", what, completions));
+    let mut actual = analysis.file_text(position.file_id).unwrap().to_string();
+    completion.text_edit().apply(&mut actual);
+    assert_eq_text!(&ra_fixture_after, &actual)
+}
+
+pub(crate) fn check_pattern_is_applicable(code: &str, check: fn(SyntaxElement) -> bool) {
+    let (analysis, pos) = analysis_and_position(code);
+    analysis
+        .with_db(|db| {
+            let sema = Semantics::new(db);
+            let original_file = sema.parse(pos.file_id);
+            let token = original_file.syntax().token_at_offset(pos.offset).left_biased().unwrap();
+            assert!(check(NodeOrToken::Token(token)));
+        })
+        .unwrap();
+}
+
+pub(crate) fn get_all_completion_items(
+    config: CompletionConfig,
+    code: &str,
+) -> Vec<CompletionItem> {
+    let (analysis, position) = analysis_and_position(code);
+    analysis.completions(&config, position).unwrap().unwrap().into()
+}
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
new file mode 100644
index 000000000..a3ec98178
--- /dev/null
+++ b/crates/ide/src/diagnostics.rs
@@ -0,0 +1,678 @@
+//! Collects diagnostics & fixits  for a single file.
+//!
+//! The tricky bit here is that diagnostics are produced by hir in terms of
+//! macro-expanded files, but we need to present them to the users in terms of
+//! original files. So we need to map the ranges.
+
+use std::cell::RefCell;
+
+use base_db::SourceDatabase;
+use hir::{diagnostics::DiagnosticSinkBuilder, Semantics};
+use ide_db::RootDatabase;
+use itertools::Itertools;
+use syntax::{
+    ast::{self, AstNode},
+    SyntaxNode, TextRange, T,
+};
+use text_edit::TextEdit;
+
+use crate::{Diagnostic, FileId, Fix, SourceFileEdit};
+
+mod diagnostics_with_fix;
+use diagnostics_with_fix::DiagnosticWithFix;
+
+#[derive(Debug, Copy, Clone)]
+pub enum Severity {
+    Error,
+    WeakWarning,
+}
+
+pub(crate) fn diagnostics(
+    db: &RootDatabase,
+    file_id: FileId,
+    enable_experimental: bool,
+) -> Vec<Diagnostic> {
+    let _p = profile::span("diagnostics");
+    let sema = Semantics::new(db);
+    let parse = db.parse(file_id);
+    let mut res = Vec::new();
+
+    // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
+    res.extend(parse.errors().iter().take(128).map(|err| Diagnostic {
+        range: err.range(),
+        message: format!("Syntax Error: {}", err),
+        severity: Severity::Error,
+        fix: None,
+    }));
+
+    for node in parse.tree().syntax().descendants() {
+        check_unnecessary_braces_in_use_statement(&mut res, file_id, &node);
+        check_struct_shorthand_initialization(&mut res, file_id, &node);
+    }
+    let res = RefCell::new(res);
+    let mut sink = DiagnosticSinkBuilder::new()
+        .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+        })
+        .on::<hir::diagnostics::MissingFields, _>(|d| {
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+        })
+        .on::<hir::diagnostics::MissingOkInTailExpr, _>(|d| {
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+        })
+        .on::<hir::diagnostics::NoSuchField, _>(|d| {
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+        })
+        // Only collect experimental diagnostics when they're enabled.
+        .filter(|diag| !diag.is_experimental() || enable_experimental)
+        // Diagnostics not handled above get no fix and default treatment.
+        .build(|d| {
+            res.borrow_mut().push(Diagnostic {
+                message: d.message(),
+                range: sema.diagnostics_display_range(d).range,
+                severity: Severity::Error,
+                fix: None,
+            })
+        });
+
+    if let Some(m) = sema.to_module_def(file_id) {
+        m.diagnostics(db, &mut sink);
+    };
+    drop(sink);
+    res.into_inner()
+}
+
+fn diagnostic_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
+    Diagnostic {
+        range: sema.diagnostics_display_range(d).range,
+        message: d.message(),
+        severity: Severity::Error,
+        fix: d.fix(&sema),
+    }
+}
+
+fn check_unnecessary_braces_in_use_statement(
+    acc: &mut Vec<Diagnostic>,
+    file_id: FileId,
+    node: &SyntaxNode,
+) -> Option<()> {
+    let use_tree_list = ast::UseTreeList::cast(node.clone())?;
+    if let Some((single_use_tree,)) = use_tree_list.use_trees().collect_tuple() {
+        let use_range = use_tree_list.syntax().text_range();
+        let edit =
+            text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(&single_use_tree)
+                .unwrap_or_else(|| {
+                    let to_replace = single_use_tree.syntax().text().to_string();
+                    let mut edit_builder = TextEdit::builder();
+                    edit_builder.delete(use_range);
+                    edit_builder.insert(use_range.start(), to_replace);
+                    edit_builder.finish()
+                });
+
+        acc.push(Diagnostic {
+            range: use_range,
+            message: "Unnecessary braces in use statement".to_string(),
+            severity: Severity::WeakWarning,
+            fix: Some(Fix::new(
+                "Remove unnecessary braces",
+                SourceFileEdit { file_id, edit }.into(),
+                use_range,
+            )),
+        });
+    }
+
+    Some(())
+}
+
+fn text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(
+    single_use_tree: &ast::UseTree,
+) -> Option<TextEdit> {
+    let use_tree_list_node = single_use_tree.syntax().parent()?;
+    if single_use_tree.path()?.segment()?.syntax().first_child_or_token()?.kind() == T![self] {
+        let start = use_tree_list_node.prev_sibling_or_token()?.text_range().start();
+        let end = use_tree_list_node.text_range().end();
+        return Some(TextEdit::delete(TextRange::new(start, end)));
+    }
+    None
+}
+
+fn check_struct_shorthand_initialization(
+    acc: &mut Vec<Diagnostic>,
+    file_id: FileId,
+    node: &SyntaxNode,
+) -> Option<()> {
+    let record_lit = ast::RecordExpr::cast(node.clone())?;
+    let record_field_list = record_lit.record_expr_field_list()?;
+    for record_field in record_field_list.fields() {
+        if let (Some(name_ref), Some(expr)) = (record_field.name_ref(), record_field.expr()) {
+            let field_name = name_ref.syntax().text().to_string();
+            let field_expr = expr.syntax().text().to_string();
+            let field_name_is_tup_index = name_ref.as_tuple_field().is_some();
+            if field_name == field_expr && !field_name_is_tup_index {
+                let mut edit_builder = TextEdit::builder();
+                edit_builder.delete(record_field.syntax().text_range());
+                edit_builder.insert(record_field.syntax().text_range().start(), field_name);
+                let edit = edit_builder.finish();
+
+                let field_range = record_field.syntax().text_range();
+                acc.push(Diagnostic {
+                    range: field_range,
+                    message: "Shorthand struct initialization".to_string(),
+                    severity: Severity::WeakWarning,
+                    fix: Some(Fix::new(
+                        "Use struct shorthand initialization",
+                        SourceFileEdit { file_id, edit }.into(),
+                        field_range,
+                    )),
+                });
+            }
+        }
+    }
+    Some(())
+}
+
+#[cfg(test)]
+mod tests {
+    use stdx::trim_indent;
+    use test_utils::assert_eq_text;
+
+    use crate::mock_analysis::{analysis_and_position, single_file, MockAnalysis};
+    use expect::{expect, Expect};
+
+    /// Takes a multi-file input fixture with annotated cursor positions,
+    /// and checks that:
+    ///  * a diagnostic is produced
+    ///  * this diagnostic fix trigger range touches the input cursor position
+    ///  * that the contents of the file containing the cursor match `after` after the diagnostic fix is applied
+    fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let after = trim_indent(ra_fixture_after);
+
+        let (analysis, file_position) = analysis_and_position(ra_fixture_before);
+        let diagnostic = analysis.diagnostics(file_position.file_id, true).unwrap().pop().unwrap();
+        let mut fix = diagnostic.fix.unwrap();
+        let edit = fix.source_change.source_file_edits.pop().unwrap().edit;
+        let target_file_contents = analysis.file_text(file_position.file_id).unwrap();
+        let actual = {
+            let mut actual = target_file_contents.to_string();
+            edit.apply(&mut actual);
+            actual
+        };
+
+        assert_eq_text!(&after, &actual);
+        assert!(
+            fix.fix_trigger_range.start() <= file_position.offset
+                && fix.fix_trigger_range.end() >= file_position.offset,
+            "diagnostic fix range {:?} does not touch cursor position {:?}",
+            fix.fix_trigger_range,
+            file_position.offset
+        );
+    }
+
+    /// Checks that a diagnostic applies to the file containing the `<|>` cursor marker
+    /// which has a fix that can apply to other files.
+    fn check_apply_diagnostic_fix_in_other_file(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let (analysis, file_pos) = analysis_and_position(ra_fixture_before);
+        let current_file_id = file_pos.file_id;
+        let diagnostic = analysis.diagnostics(current_file_id, true).unwrap().pop().unwrap();
+        let mut fix = diagnostic.fix.unwrap();
+        let edit = fix.source_change.source_file_edits.pop().unwrap();
+        let changed_file_id = edit.file_id;
+        let before = analysis.file_text(changed_file_id).unwrap();
+        let actual = {
+            let mut actual = before.to_string();
+            edit.edit.apply(&mut actual);
+            actual
+        };
+        assert_eq_text!(ra_fixture_after, &actual);
+    }
+
+    /// Takes a multi-file input fixture with annotated cursor position and checks that no diagnostics
+    /// apply to the file containing the cursor.
+    fn check_no_diagnostics(ra_fixture: &str) {
+        let mock = MockAnalysis::with_files(ra_fixture);
+        let files = mock.files().map(|(it, _)| it).collect::<Vec<_>>();
+        let analysis = mock.analysis();
+        let diagnostics = files
+            .into_iter()
+            .flat_map(|file_id| analysis.diagnostics(file_id, true).unwrap())
+            .collect::<Vec<_>>();
+        assert_eq!(diagnostics.len(), 0, "unexpected diagnostics:\n{:#?}", diagnostics);
+    }
+
+    fn check_expect(ra_fixture: &str, expect: Expect) {
+        let (analysis, file_id) = single_file(ra_fixture);
+        let diagnostics = analysis.diagnostics(file_id, true).unwrap();
+        expect.assert_debug_eq(&diagnostics)
+    }
+
+    #[test]
+    fn test_wrap_return_type() {
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
+
+fn div(x: i32, y: i32) -> Result<i32, ()> {
+    if y == 0 {
+        return Err(());
+    }
+    x / y<|>
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
+
+fn div(x: i32, y: i32) -> Result<i32, ()> {
+    if y == 0 {
+        return Err(());
+    }
+    Ok(x / y)
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_wrap_return_type_handles_generic_functions() {
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
+
+fn div<T>(x: T) -> Result<T, i32> {
+    if x == 0 {
+        return Err(7);
+    }
+    <|>x
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
+
+fn div<T>(x: T) -> Result<T, i32> {
+    if x == 0 {
+        return Err(7);
+    }
+    Ok(x)
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_wrap_return_type_handles_type_aliases() {
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
+
+type MyResult<T> = Result<T, ()>;
+
+fn div(x: i32, y: i32) -> MyResult<i32> {
+    if y == 0 {
+        return Err(());
+    }
+    x <|>/ y
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
+
+type MyResult<T> = Result<T, ()>;
+
+fn div(x: i32, y: i32) -> MyResult<i32> {
+    if y == 0 {
+        return Err(());
+    }
+    Ok(x / y)
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_wrap_return_type_not_applicable_when_expr_type_does_not_match_ok_type() {
+        check_no_diagnostics(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
+
+fn foo() -> Result<(), i32> { 0 }
+
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_wrap_return_type_not_applicable_when_return_type_is_not_result() {
+        check_no_diagnostics(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
+
+enum SomeOtherEnum { Ok(i32), Err(String) }
+
+fn foo() -> SomeOtherEnum { 0 }
+
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_empty() {
+        check_fix(
+            r#"
+struct TestStruct { one: i32, two: i64 }
+
+fn test_fn() {
+    let s = TestStruct {<|>};
+}
+"#,
+            r#"
+struct TestStruct { one: i32, two: i64 }
+
+fn test_fn() {
+    let s = TestStruct { one: (), two: ()};
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_self() {
+        check_fix(
+            r#"
+struct TestStruct { one: i32 }
+
+impl TestStruct {
+    fn test_fn() { let s = Self {<|>}; }
+}
+"#,
+            r#"
+struct TestStruct { one: i32 }
+
+impl TestStruct {
+    fn test_fn() { let s = Self { one: ()}; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_enum() {
+        check_fix(
+            r#"
+enum Expr {
+    Bin { lhs: Box<Expr>, rhs: Box<Expr> }
+}
+
+impl Expr {
+    fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
+        Expr::Bin {<|> }
+    }
+}
+"#,
+            r#"
+enum Expr {
+    Bin { lhs: Box<Expr>, rhs: Box<Expr> }
+}
+
+impl Expr {
+    fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
+        Expr::Bin { lhs: (), rhs: () }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_partial() {
+        check_fix(
+            r#"
+struct TestStruct { one: i32, two: i64 }
+
+fn test_fn() {
+    let s = TestStruct{ two: 2<|> };
+}
+"#,
+            r"
+struct TestStruct { one: i32, two: i64 }
+
+fn test_fn() {
+    let s = TestStruct{ two: 2, one: () };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_no_diagnostic() {
+        check_no_diagnostics(
+            r"
+            struct TestStruct { one: i32, two: i64 }
+
+            fn test_fn() {
+                let one = 1;
+                let s = TestStruct{ one, two: 2 };
+            }
+        ",
+        );
+    }
+
+    #[test]
+    fn test_fill_struct_fields_no_diagnostic_on_spread() {
+        check_no_diagnostics(
+            r"
+            struct TestStruct { one: i32, two: i64 }
+
+            fn test_fn() {
+                let one = 1;
+                let s = TestStruct{ ..a };
+            }
+        ",
+        );
+    }
+
+    #[test]
+    fn test_unresolved_module_diagnostic() {
+        check_expect(
+            r#"mod foo;"#,
+            expect![[r#"
+                [
+                    Diagnostic {
+                        message: "unresolved module",
+                        range: 0..8,
+                        severity: Error,
+                        fix: Some(
+                            Fix {
+                                label: "Create module",
+                                source_change: SourceChange {
+                                    source_file_edits: [],
+                                    file_system_edits: [
+                                        CreateFile {
+                                            anchor: FileId(
+                                                1,
+                                            ),
+                                            dst: "foo.rs",
+                                        },
+                                    ],
+                                    is_snippet: false,
+                                },
+                                fix_trigger_range: 0..8,
+                            },
+                        ),
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn range_mapping_out_of_macros() {
+        // FIXME: this is very wrong, but somewhat tricky to fix.
+        check_fix(
+            r#"
+fn some() {}
+fn items() {}
+fn here() {}
+
+macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
+
+fn main() {
+    let _x = id![Foo { a: <|>42 }];
+}
+
+pub struct Foo { pub a: i32, pub b: i32 }
+"#,
+            r#"
+fn {a:42, b: ()} {}
+fn items() {}
+fn here() {}
+
+macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
+
+fn main() {
+    let _x = id![Foo { a: 42 }];
+}
+
+pub struct Foo { pub a: i32, pub b: i32 }
+"#,
+        );
+    }
+
+    #[test]
+    fn test_check_unnecessary_braces_in_use_statement() {
+        check_no_diagnostics(
+            r#"
+use a;
+use a::{c, d::e};
+"#,
+        );
+        check_fix(r#"use {<|>b};"#, r#"use b;"#);
+        check_fix(r#"use {b<|>};"#, r#"use b;"#);
+        check_fix(r#"use a::{c<|>};"#, r#"use a::c;"#);
+        check_fix(r#"use a::{self<|>};"#, r#"use a;"#);
+        check_fix(r#"use a::{c, d::{e<|>}};"#, r#"use a::{c, d::e};"#);
+    }
+
+    #[test]
+    fn test_check_struct_shorthand_initialization() {
+        check_no_diagnostics(
+            r#"
+struct A { a: &'static str }
+fn main() { A { a: "hello" } }
+"#,
+        );
+        check_no_diagnostics(
+            r#"
+struct A(usize);
+fn main() { A { 0: 0 } }
+"#,
+        );
+
+        check_fix(
+            r#"
+struct A { a: &'static str }
+fn main() {
+    let a = "haha";
+    A { a<|>: a }
+}
+"#,
+            r#"
+struct A { a: &'static str }
+fn main() {
+    let a = "haha";
+    A { a }
+}
+"#,
+        );
+
+        check_fix(
+            r#"
+struct A { a: &'static str, b: &'static str }
+fn main() {
+    let a = "haha";
+    let b = "bb";
+    A { a<|>: a, b }
+}
+"#,
+            r#"
+struct A { a: &'static str, b: &'static str }
+fn main() {
+    let a = "haha";
+    let b = "bb";
+    A { a, b }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_add_field_from_usage() {
+        check_fix(
+            r"
+fn main() {
+    Foo { bar: 3, baz<|>: false};
+}
+struct Foo {
+    bar: i32
+}
+",
+            r"
+fn main() {
+    Foo { bar: 3, baz: false};
+}
+struct Foo {
+    bar: i32,
+    baz: bool
+}
+",
+        )
+    }
+
+    #[test]
+    fn test_add_field_in_other_file_from_usage() {
+        check_apply_diagnostic_fix_in_other_file(
+            r"
+            //- /main.rs
+            mod foo;
+
+            fn main() {
+                <|>foo::Foo { bar: 3, baz: false};
+            }
+            //- /foo.rs
+            struct Foo {
+                bar: i32
+            }
+            ",
+            r"
+            struct Foo {
+                bar: i32,
+                pub(crate) baz: bool
+            }
+            ",
+        )
+    }
+}
diff --git a/crates/ide/src/diagnostics/diagnostics_with_fix.rs b/crates/ide/src/diagnostics/diagnostics_with_fix.rs
new file mode 100644
index 000000000..85b46c995
--- /dev/null
+++ b/crates/ide/src/diagnostics/diagnostics_with_fix.rs
@@ -0,0 +1,171 @@
+//! Provides a way to attach fixes to the diagnostics.
+//! The same module also has all curret custom fixes for the diagnostics implemented.
+use crate::Fix;
+use ast::{edit::IndentLevel, make};
+use base_db::FileId;
+use hir::{
+    db::AstDatabase,
+    diagnostics::{Diagnostic, MissingFields, MissingOkInTailExpr, NoSuchField, UnresolvedModule},
+    HasSource, HirDisplay, Semantics, VariantDef,
+};
+use ide_db::{
+    source_change::{FileSystemEdit, SourceFileEdit},
+    RootDatabase,
+};
+use syntax::{algo, ast, AstNode};
+use text_edit::TextEdit;
+
+/// A [Diagnostic] that potentially has a fix available.
+///
+/// [Diagnostic]: hir::diagnostics::Diagnostic
+pub trait DiagnosticWithFix: Diagnostic {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix>;
+}
+
+impl DiagnosticWithFix for UnresolvedModule {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        let unresolved_module = self.decl.to_node(&root);
+        Some(Fix::new(
+            "Create module",
+            FileSystemEdit::CreateFile {
+                anchor: self.file.original_file(sema.db),
+                dst: self.candidate.clone(),
+            }
+            .into(),
+            unresolved_module.syntax().text_range(),
+        ))
+    }
+}
+
+impl DiagnosticWithFix for NoSuchField {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        missing_record_expr_field_fix(
+            &sema,
+            self.file.original_file(sema.db),
+            &self.field.to_node(&root),
+        )
+    }
+}
+
+impl DiagnosticWithFix for MissingFields {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        // Note that although we could add a diagnostics to
+        // fill the missing tuple field, e.g :
+        // `struct A(usize);`
+        // `let a = A { 0: () }`
+        // but it is uncommon usage and it should not be encouraged.
+        if self.missed_fields.iter().any(|it| it.as_tuple_index().is_some()) {
+            return None;
+        }
+
+        let root = sema.db.parse_or_expand(self.file)?;
+        let old_field_list = self.field_list_parent.to_node(&root).record_expr_field_list()?;
+        let mut new_field_list = old_field_list.clone();
+        for f in self.missed_fields.iter() {
+            let field =
+                make::record_expr_field(make::name_ref(&f.to_string()), Some(make::expr_unit()));
+            new_field_list = new_field_list.append_field(&field);
+        }
+
+        let edit = {
+            let mut builder = TextEdit::builder();
+            algo::diff(&old_field_list.syntax(), &new_field_list.syntax())
+                .into_text_edit(&mut builder);
+            builder.finish()
+        };
+        Some(Fix::new(
+            "Fill struct fields",
+            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into(),
+            sema.original_range(&old_field_list.syntax()).range,
+        ))
+    }
+}
+
+impl DiagnosticWithFix for MissingOkInTailExpr {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        let tail_expr = self.expr.to_node(&root);
+        let tail_expr_range = tail_expr.syntax().text_range();
+        let edit = TextEdit::replace(tail_expr_range, format!("Ok({})", tail_expr.syntax()));
+        let source_change =
+            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into();
+        Some(Fix::new("Wrap with ok", source_change, tail_expr_range))
+    }
+}
+
+fn missing_record_expr_field_fix(
+    sema: &Semantics<RootDatabase>,
+    usage_file_id: FileId,
+    record_expr_field: &ast::RecordExprField,
+) -> Option<Fix> {
+    let record_lit = ast::RecordExpr::cast(record_expr_field.syntax().parent()?.parent()?)?;
+    let def_id = sema.resolve_variant(record_lit)?;
+    let module;
+    let def_file_id;
+    let record_fields = match VariantDef::from(def_id) {
+        VariantDef::Struct(s) => {
+            module = s.module(sema.db);
+            let source = s.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_list()?;
+            record_field_list(fields)?
+        }
+        VariantDef::Union(u) => {
+            module = u.module(sema.db);
+            let source = u.source(sema.db);
+            def_file_id = source.file_id;
+            source.value.record_field_list()?
+        }
+        VariantDef::EnumVariant(e) => {
+            module = e.module(sema.db);
+            let source = e.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_list()?;
+            record_field_list(fields)?
+        }
+    };
+    let def_file_id = def_file_id.original_file(sema.db);
+
+    let new_field_type = sema.type_of_expr(&record_expr_field.expr()?)?;
+    if new_field_type.is_unknown() {
+        return None;
+    }
+    let new_field = make::record_field(
+        record_expr_field.field_name()?,
+        make::ty(&new_field_type.display_source_code(sema.db, module.into()).ok()?),
+    );
+
+    let last_field = record_fields.fields().last()?;
+    let last_field_syntax = last_field.syntax();
+    let indent = IndentLevel::from_node(last_field_syntax);
+
+    let mut new_field = new_field.to_string();
+    if usage_file_id != def_file_id {
+        new_field = format!("pub(crate) {}", new_field);
+    }
+    new_field = format!("\n{}{}", indent, new_field);
+
+    let needs_comma = !last_field_syntax.to_string().ends_with(',');
+    if needs_comma {
+        new_field = format!(",{}", new_field);
+    }
+
+    let source_change = SourceFileEdit {
+        file_id: def_file_id,
+        edit: TextEdit::insert(last_field_syntax.text_range().end(), new_field),
+    };
+    return Some(Fix::new(
+        "Create field",
+        source_change.into(),
+        record_expr_field.syntax().text_range(),
+    ));
+
+    fn record_field_list(field_def_list: ast::FieldList) -> Option<ast::RecordFieldList> {
+        match field_def_list {
+            ast::FieldList::RecordFieldList(it) => Some(it),
+            ast::FieldList::TupleFieldList(_) => None,
+        }
+    }
+}
diff --git a/crates/ide/src/display.rs b/crates/ide/src/display.rs
new file mode 100644
index 000000000..41b5bdc49
--- /dev/null
+++ b/crates/ide/src/display.rs
@@ -0,0 +1,83 @@
+//! This module contains utilities for turning SyntaxNodes and HIR types
+//! into types that may be used to render in a UI.
+
+mod navigation_target;
+mod short_label;
+
+use syntax::{
+    ast::{self, AstNode, AttrsOwner, GenericParamsOwner, NameOwner},
+    SyntaxKind::{ATTR, COMMENT},
+};
+
+use ast::VisibilityOwner;
+use stdx::format_to;
+
+pub use navigation_target::NavigationTarget;
+pub(crate) use navigation_target::{ToNav, TryToNav};
+pub(crate) use short_label::ShortLabel;
+
+pub(crate) fn function_declaration(node: &ast::Fn) -> String {
+    let mut buf = String::new();
+    if let Some(vis) = node.visibility() {
+        format_to!(buf, "{} ", vis);
+    }
+    if node.async_token().is_some() {
+        format_to!(buf, "async ");
+    }
+    if node.const_token().is_some() {
+        format_to!(buf, "const ");
+    }
+    if node.unsafe_token().is_some() {
+        format_to!(buf, "unsafe ");
+    }
+    if let Some(abi) = node.abi() {
+        // Keyword `extern` is included in the string.
+        format_to!(buf, "{} ", abi);
+    }
+    if let Some(name) = node.name() {
+        format_to!(buf, "fn {}", name)
+    }
+    if let Some(type_params) = node.generic_param_list() {
+        format_to!(buf, "{}", type_params);
+    }
+    if let Some(param_list) = node.param_list() {
+        format_to!(buf, "{}", param_list);
+    }
+    if let Some(ret_type) = node.ret_type() {
+        if ret_type.ty().is_some() {
+            format_to!(buf, " {}", ret_type);
+        }
+    }
+    if let Some(where_clause) = node.where_clause() {
+        format_to!(buf, "\n{}", where_clause);
+    }
+    buf
+}
+
+pub(crate) fn const_label(node: &ast::Const) -> String {
+    let label: String = node
+        .syntax()
+        .children_with_tokens()
+        .filter(|child| !(child.kind() == COMMENT || child.kind() == ATTR))
+        .map(|node| node.to_string())
+        .collect();
+
+    label.trim().to_owned()
+}
+
+pub(crate) fn type_label(node: &ast::TypeAlias) -> String {
+    let label: String = node
+        .syntax()
+        .children_with_tokens()
+        .filter(|child| !(child.kind() == COMMENT || child.kind() == ATTR))
+        .map(|node| node.to_string())
+        .collect();
+
+    label.trim().to_owned()
+}
+
+pub(crate) fn macro_label(node: &ast::MacroCall) -> String {
+    let name = node.name().map(|name| name.syntax().text().to_string()).unwrap_or_default();
+    let vis = if node.has_atom_attr("macro_export") { "#[macro_export]\n" } else { "" };
+    format!("{}macro_rules! {}", vis, name)
+}
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
new file mode 100644
index 000000000..e77106177
--- /dev/null
+++ b/crates/ide/src/display/navigation_target.rs
@@ -0,0 +1,491 @@
+//! FIXME: write short doc here
+
+use base_db::{FileId, SourceDatabase};
+use either::Either;
+use hir::{original_range, AssocItem, FieldSource, HasSource, InFile, ModuleSource};
+use ide_db::{defs::Definition, RootDatabase};
+use syntax::{
+    ast::{self, DocCommentsOwner, NameOwner},
+    match_ast, AstNode, SmolStr,
+    SyntaxKind::{self, IDENT_PAT, TYPE_PARAM},
+    TextRange,
+};
+
+use crate::FileSymbol;
+
+use super::short_label::ShortLabel;
+
+/// `NavigationTarget` represents and element in the editor's UI which you can
+/// click on to navigate to a particular piece of code.
+///
+/// Typically, a `NavigationTarget` corresponds to some element in the source
+/// code, like a function or a struct, but this is not strictly required.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct NavigationTarget {
+    pub file_id: FileId,
+    /// Range which encompasses the whole element.
+    ///
+    /// Should include body, doc comments, attributes, etc.
+    ///
+    /// Clients should use this range to answer "is the cursor inside the
+    /// element?" question.
+    pub full_range: TextRange,
+    /// A "most interesting" range withing the `full_range`.
+    ///
+    /// Typically, `full_range` is the whole syntax node, including doc
+    /// comments, and `focus_range` is the range of the identifier. "Most
+    /// interesting" range within the full range, typically the range of
+    /// identifier.
+    ///
+    /// Clients should place the cursor on this range when navigating to this target.
+    pub focus_range: Option<TextRange>,
+    pub name: SmolStr,
+    pub kind: SyntaxKind,
+    pub container_name: Option<SmolStr>,
+    pub description: Option<String>,
+    pub docs: Option<String>,
+}
+
+pub(crate) trait ToNav {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget;
+}
+
+pub(crate) trait TryToNav {
+    fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget>;
+}
+
+impl NavigationTarget {
+    pub fn focus_or_full_range(&self) -> TextRange {
+        self.focus_range.unwrap_or(self.full_range)
+    }
+
+    pub(crate) fn from_module_to_decl(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
+        let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
+        if let Some(src) = module.declaration_source(db) {
+            let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
+            let mut res = NavigationTarget::from_syntax(
+                frange.file_id,
+                name,
+                None,
+                frange.range,
+                src.value.syntax().kind(),
+            );
+            res.docs = src.value.doc_comment_text();
+            res.description = src.value.short_label();
+            return res;
+        }
+        module.to_nav(db)
+    }
+
+    #[cfg(test)]
+    pub(crate) fn assert_match(&self, expected: &str) {
+        let actual = self.debug_render();
+        test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_render(&self) -> String {
+        let mut buf =
+            format!("{} {:?} {:?} {:?}", self.name, self.kind, self.file_id, self.full_range);
+        if let Some(focus_range) = self.focus_range {
+            buf.push_str(&format!(" {:?}", focus_range))
+        }
+        if let Some(container_name) = &self.container_name {
+            buf.push_str(&format!(" {}", container_name))
+        }
+        buf
+    }
+
+    /// Allows `NavigationTarget` to be created from a `NameOwner`
+    pub(crate) fn from_named(
+        db: &RootDatabase,
+        node: InFile<&dyn ast::NameOwner>,
+    ) -> NavigationTarget {
+        let name =
+            node.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
+        let focus_range =
+            node.value.name().map(|it| original_range(db, node.with_value(it.syntax())).range);
+        let frange = original_range(db, node.map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            focus_range,
+            frange.range,
+            node.value.syntax().kind(),
+        )
+    }
+
+    /// Allows `NavigationTarget` to be created from a `DocCommentsOwner` and a `NameOwner`
+    pub(crate) fn from_doc_commented(
+        db: &RootDatabase,
+        named: InFile<&dyn ast::NameOwner>,
+        node: InFile<&dyn ast::DocCommentsOwner>,
+    ) -> NavigationTarget {
+        let name =
+            named.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
+        let frange = original_range(db, node.map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            None,
+            frange.range,
+            node.value.syntax().kind(),
+        )
+    }
+
+    fn from_syntax(
+        file_id: FileId,
+        name: SmolStr,
+        focus_range: Option<TextRange>,
+        full_range: TextRange,
+        kind: SyntaxKind,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name,
+            kind,
+            full_range,
+            focus_range,
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
+impl ToNav for FileSymbol {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        NavigationTarget {
+            file_id: self.file_id,
+            name: self.name.clone(),
+            kind: self.kind,
+            full_range: self.range,
+            focus_range: self.name_range,
+            container_name: self.container_name.clone(),
+            description: description_from_symbol(db, self),
+            docs: docs_from_symbol(db, self),
+        }
+    }
+}
+
+impl TryToNav for Definition {
+    fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget> {
+        match self {
+            Definition::Macro(it) => Some(it.to_nav(db)),
+            Definition::Field(it) => Some(it.to_nav(db)),
+            Definition::ModuleDef(it) => it.try_to_nav(db),
+            Definition::SelfType(it) => Some(it.to_nav(db)),
+            Definition::Local(it) => Some(it.to_nav(db)),
+            Definition::TypeParam(it) => Some(it.to_nav(db)),
+        }
+    }
+}
+
+impl TryToNav for hir::ModuleDef {
+    fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget> {
+        let res = match self {
+            hir::ModuleDef::Module(it) => it.to_nav(db),
+            hir::ModuleDef::Function(it) => it.to_nav(db),
+            hir::ModuleDef::Adt(it) => it.to_nav(db),
+            hir::ModuleDef::EnumVariant(it) => it.to_nav(db),
+            hir::ModuleDef::Const(it) => it.to_nav(db),
+            hir::ModuleDef::Static(it) => it.to_nav(db),
+            hir::ModuleDef::Trait(it) => it.to_nav(db),
+            hir::ModuleDef::TypeAlias(it) => it.to_nav(db),
+            hir::ModuleDef::BuiltinType(_) => return None,
+        };
+        Some(res)
+    }
+}
+
+pub(crate) trait ToNavFromAst {}
+impl ToNavFromAst for hir::Function {}
+impl ToNavFromAst for hir::Const {}
+impl ToNavFromAst for hir::Static {}
+impl ToNavFromAst for hir::Struct {}
+impl ToNavFromAst for hir::Enum {}
+impl ToNavFromAst for hir::EnumVariant {}
+impl ToNavFromAst for hir::Union {}
+impl ToNavFromAst for hir::TypeAlias {}
+impl ToNavFromAst for hir::Trait {}
+
+impl<D> ToNav for D
+where
+    D: HasSource + ToNavFromAst + Copy,
+    D::Ast: ast::DocCommentsOwner + ast::NameOwner + ShortLabel,
+{
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res.description = src.value.short_label();
+        res
+    }
+}
+
+impl ToNav for hir::Module {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.definition_source(db);
+        let name = self.name(db).map(|it| it.to_string().into()).unwrap_or_default();
+        let (syntax, focus) = match &src.value {
+            ModuleSource::SourceFile(node) => (node.syntax(), None),
+            ModuleSource::Module(node) => {
+                (node.syntax(), node.name().map(|it| it.syntax().text_range()))
+            }
+        };
+        let frange = original_range(db, src.with_value(syntax));
+        NavigationTarget::from_syntax(frange.file_id, name, focus, frange.range, syntax.kind())
+    }
+}
+
+impl ToNav for hir::ImplDef {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let derive_attr = self.is_builtin_derive(db);
+        let frange = if let Some(item) = &derive_attr {
+            original_range(db, item.syntax())
+        } else {
+            original_range(db, src.as_ref().map(|it| it.syntax()))
+        };
+        let focus_range = if derive_attr.is_some() {
+            None
+        } else {
+            src.value.self_ty().map(|ty| original_range(db, src.with_value(ty.syntax())).range)
+        };
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            "impl".into(),
+            focus_range,
+            frange.range,
+            src.value.syntax().kind(),
+        )
+    }
+}
+
+impl ToNav for hir::Field {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+
+        match &src.value {
+            FieldSource::Named(it) => {
+                let mut res = NavigationTarget::from_named(db, src.with_value(it));
+                res.docs = it.doc_comment_text();
+                res.description = it.short_label();
+                res
+            }
+            FieldSource::Pos(it) => {
+                let frange = original_range(db, src.with_value(it.syntax()));
+                NavigationTarget::from_syntax(
+                    frange.file_id,
+                    "".into(),
+                    None,
+                    frange.range,
+                    it.syntax().kind(),
+                )
+            }
+        }
+    }
+}
+
+impl ToNav for hir::MacroDef {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        log::debug!("nav target {:#?}", src.value.syntax());
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res
+    }
+}
+
+impl ToNav for hir::Adt {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        match self {
+            hir::Adt::Struct(it) => it.to_nav(db),
+            hir::Adt::Union(it) => it.to_nav(db),
+            hir::Adt::Enum(it) => it.to_nav(db),
+        }
+    }
+}
+
+impl ToNav for hir::AssocItem {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        match self {
+            AssocItem::Function(it) => it.to_nav(db),
+            AssocItem::Const(it) => it.to_nav(db),
+            AssocItem::TypeAlias(it) => it.to_nav(db),
+        }
+    }
+}
+
+impl ToNav for hir::Local {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let node = match &src.value {
+            Either::Left(bind_pat) => {
+                bind_pat.name().map_or_else(|| bind_pat.syntax().clone(), |it| it.syntax().clone())
+            }
+            Either::Right(it) => it.syntax().clone(),
+        };
+        let full_range = original_range(db, src.with_value(&node));
+        let name = match self.name(db) {
+            Some(it) => it.to_string().into(),
+            None => "".into(),
+        };
+        NavigationTarget {
+            file_id: full_range.file_id,
+            name,
+            kind: IDENT_PAT,
+            full_range: full_range.range,
+            focus_range: None,
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
+impl ToNav for hir::TypeParam {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let full_range = match &src.value {
+            Either::Left(it) => it.syntax().text_range(),
+            Either::Right(it) => it.syntax().text_range(),
+        };
+        let focus_range = match &src.value {
+            Either::Left(_) => None,
+            Either::Right(it) => it.name().map(|it| it.syntax().text_range()),
+        };
+        NavigationTarget {
+            file_id: src.file_id.original_file(db),
+            name: self.name(db).to_string().into(),
+            kind: TYPE_PARAM,
+            full_range,
+            focus_range,
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
+pub(crate) fn docs_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option<String> {
+    let parse = db.parse(symbol.file_id);
+    let node = symbol.ptr.to_node(parse.tree().syntax());
+
+    match_ast! {
+        match node {
+            ast::Fn(it) => it.doc_comment_text(),
+            ast::Struct(it) => it.doc_comment_text(),
+            ast::Enum(it) => it.doc_comment_text(),
+            ast::Trait(it) => it.doc_comment_text(),
+            ast::Module(it) => it.doc_comment_text(),
+            ast::TypeAlias(it) => it.doc_comment_text(),
+            ast::Const(it) => it.doc_comment_text(),
+            ast::Static(it) => it.doc_comment_text(),
+            ast::RecordField(it) => it.doc_comment_text(),
+            ast::Variant(it) => it.doc_comment_text(),
+            ast::MacroCall(it) => it.doc_comment_text(),
+            _ => None,
+        }
+    }
+}
+
+/// Get a description of a symbol.
+///
+/// e.g. `struct Name`, `enum Name`, `fn Name`
+pub(crate) fn description_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option<String> {
+    let parse = db.parse(symbol.file_id);
+    let node = symbol.ptr.to_node(parse.tree().syntax());
+
+    match_ast! {
+        match node {
+            ast::Fn(it) => it.short_label(),
+            ast::Struct(it) => it.short_label(),
+            ast::Enum(it) => it.short_label(),
+            ast::Trait(it) => it.short_label(),
+            ast::Module(it) => it.short_label(),
+            ast::TypeAlias(it) => it.short_label(),
+            ast::Const(it) => it.short_label(),
+            ast::Static(it) => it.short_label(),
+            ast::RecordField(it) => it.short_label(),
+            ast::Variant(it) => it.short_label(),
+            _ => None,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::expect;
+
+    use crate::{mock_analysis::single_file, Query};
+
+    #[test]
+    fn test_nav_for_symbol() {
+        let (analysis, _) = single_file(
+            r#"
+enum FooInner { }
+fn foo() { enum FooInner { } }
+"#,
+        );
+
+        let navs = analysis.symbol_search(Query::new("FooInner".to_string())).unwrap();
+        expect![[r#"
+            [
+                NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 0..17,
+                    focus_range: Some(
+                        5..13,
+                    ),
+                    name: "FooInner",
+                    kind: ENUM,
+                    container_name: None,
+                    description: Some(
+                        "enum FooInner",
+                    ),
+                    docs: None,
+                },
+                NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 29..46,
+                    focus_range: Some(
+                        34..42,
+                    ),
+                    name: "FooInner",
+                    kind: ENUM,
+                    container_name: Some(
+                        "foo",
+                    ),
+                    description: Some(
+                        "enum FooInner",
+                    ),
+                    docs: None,
+                },
+            ]
+        "#]]
+        .assert_debug_eq(&navs);
+    }
+
+    #[test]
+    fn test_world_symbols_are_case_sensitive() {
+        let (analysis, _) = single_file(
+            r#"
+fn foo() {}
+struct Foo;
+"#,
+        );
+
+        let navs = analysis.symbol_search(Query::new("foo".to_string())).unwrap();
+        assert_eq!(navs.len(), 2)
+    }
+}
diff --git a/crates/ide/src/display/short_label.rs b/crates/ide/src/display/short_label.rs
new file mode 100644
index 000000000..ea49d9f97
--- /dev/null
+++ b/crates/ide/src/display/short_label.rs
@@ -0,0 +1,111 @@
+//! FIXME: write short doc here
+
+use stdx::format_to;
+use syntax::ast::{self, AstNode, NameOwner, VisibilityOwner};
+
+pub(crate) trait ShortLabel {
+    fn short_label(&self) -> Option<String>;
+}
+
+impl ShortLabel for ast::Fn {
+    fn short_label(&self) -> Option<String> {
+        Some(crate::display::function_declaration(self))
+    }
+}
+
+impl ShortLabel for ast::Struct {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "struct ")
+    }
+}
+
+impl ShortLabel for ast::Union {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "union ")
+    }
+}
+
+impl ShortLabel for ast::Enum {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "enum ")
+    }
+}
+
+impl ShortLabel for ast::Trait {
+    fn short_label(&self) -> Option<String> {
+        if self.unsafe_token().is_some() {
+            short_label_from_node(self, "unsafe trait ")
+        } else {
+            short_label_from_node(self, "trait ")
+        }
+    }
+}
+
+impl ShortLabel for ast::Module {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "mod ")
+    }
+}
+
+impl ShortLabel for ast::SourceFile {
+    fn short_label(&self) -> Option<String> {
+        None
+    }
+}
+
+impl ShortLabel for ast::TypeAlias {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "type ")
+    }
+}
+
+impl ShortLabel for ast::Const {
+    fn short_label(&self) -> Option<String> {
+        let mut new_buf = short_label_from_ty(self, self.ty(), "const ")?;
+        if let Some(expr) = self.body() {
+            format_to!(new_buf, " = {}", expr.syntax());
+        }
+        Some(new_buf)
+    }
+}
+
+impl ShortLabel for ast::Static {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_ty(self, self.ty(), "static ")
+    }
+}
+
+impl ShortLabel for ast::RecordField {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_ty(self, self.ty(), "")
+    }
+}
+
+impl ShortLabel for ast::Variant {
+    fn short_label(&self) -> Option<String> {
+        Some(self.name()?.text().to_string())
+    }
+}
+
+fn short_label_from_ty<T>(node: &T, ty: Option<ast::Type>, prefix: &str) -> Option<String>
+where
+    T: NameOwner + VisibilityOwner,
+{
+    let mut buf = short_label_from_node(node, prefix)?;
+
+    if let Some(type_ref) = ty {
+        format_to!(buf, ": {}", type_ref.syntax());
+    }
+
+    Some(buf)
+}
+
+fn short_label_from_node<T>(node: &T, label: &str) -> Option<String>
+where
+    T: NameOwner + VisibilityOwner,
+{
+    let mut buf = node.visibility().map(|v| format!("{} ", v.syntax())).unwrap_or_default();
+    buf.push_str(label);
+    buf.push_str(node.name()?.text().as_str());
+    Some(buf)
+}
diff --git a/crates/ide/src/expand_macro.rs b/crates/ide/src/expand_macro.rs
new file mode 100644
index 000000000..31455709d
--- /dev/null
+++ b/crates/ide/src/expand_macro.rs
@@ -0,0 +1,283 @@
+use hir::Semantics;
+use ide_db::RootDatabase;
+use syntax::{
+    algo::{find_node_at_offset, SyntaxRewriter},
+    ast, AstNode, NodeOrToken, SyntaxKind,
+    SyntaxKind::*,
+    SyntaxNode, WalkEvent, T,
+};
+
+use crate::FilePosition;
+
+pub struct ExpandedMacro {
+    pub name: String,
+    pub expansion: String,
+}
+
+// Feature: Expand Macro Recursively
+//
+// Shows the full macro expansion of the macro at current cursor.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Expand macro recursively**
+// |===
+pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<ExpandedMacro> {
+    let sema = Semantics::new(db);
+    let file = sema.parse(position.file_id);
+    let name_ref = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset)?;
+    let mac = name_ref.syntax().ancestors().find_map(ast::MacroCall::cast)?;
+
+    let expanded = expand_macro_recur(&sema, &mac)?;
+
+    // FIXME:
+    // macro expansion may lose all white space information
+    // But we hope someday we can use ra_fmt for that
+    let expansion = insert_whitespaces(expanded);
+    Some(ExpandedMacro { name: name_ref.text().to_string(), expansion })
+}
+
+fn expand_macro_recur(
+    sema: &Semantics<RootDatabase>,
+    macro_call: &ast::MacroCall,
+) -> Option<SyntaxNode> {
+    let mut expanded = sema.expand(macro_call)?;
+
+    let children = expanded.descendants().filter_map(ast::MacroCall::cast);
+    let mut rewriter = SyntaxRewriter::default();
+
+    for child in children.into_iter() {
+        if let Some(new_node) = expand_macro_recur(sema, &child) {
+            // Replace the whole node if it is root
+            // `replace_descendants` will not replace the parent node
+            // but `SyntaxNode::descendants include itself
+            if expanded == *child.syntax() {
+                expanded = new_node;
+            } else {
+                rewriter.replace(child.syntax(), &new_node)
+            }
+        }
+    }
+
+    let res = rewriter.rewrite(&expanded);
+    Some(res)
+}
+
+// FIXME: It would also be cool to share logic here and in the mbe tests,
+// which are pretty unreadable at the moment.
+fn insert_whitespaces(syn: SyntaxNode) -> String {
+    let mut res = String::new();
+    let mut token_iter = syn
+        .preorder_with_tokens()
+        .filter_map(|event| {
+            if let WalkEvent::Enter(NodeOrToken::Token(token)) = event {
+                Some(token)
+            } else {
+                None
+            }
+        })
+        .peekable();
+
+    let mut indent = 0;
+    let mut last: Option<SyntaxKind> = None;
+
+    while let Some(token) = token_iter.next() {
+        let mut is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
+            token_iter.peek().map(|it| f(it.kind())).unwrap_or(default)
+        };
+        let is_last =
+            |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
+
+        res += &match token.kind() {
+            k if is_text(k) && is_next(|it| !it.is_punct(), true) => token.text().to_string() + " ",
+            L_CURLY if is_next(|it| it != R_CURLY, true) => {
+                indent += 1;
+                let leading_space = if is_last(is_text, false) { " " } else { "" };
+                format!("{}{{\n{}", leading_space, "  ".repeat(indent))
+            }
+            R_CURLY if is_last(|it| it != L_CURLY, true) => {
+                indent = indent.saturating_sub(1);
+                format!("\n{}}}", "  ".repeat(indent))
+            }
+            R_CURLY => format!("}}\n{}", "  ".repeat(indent)),
+            T![;] => format!(";\n{}", "  ".repeat(indent)),
+            T![->] => " -> ".to_string(),
+            T![=] => " = ".to_string(),
+            T![=>] => " => ".to_string(),
+            _ => token.text().to_string(),
+        };
+
+        last = Some(token.kind());
+    }
+
+    return res;
+
+    fn is_text(k: SyntaxKind) -> bool {
+        k.is_keyword() || k.is_literal() || k == IDENT
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, pos) = analysis_and_position(ra_fixture);
+        let expansion = analysis.expand_macro(pos).unwrap().unwrap();
+        let actual = format!("{}\n{}", expansion.name, expansion.expansion);
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn macro_expand_recursive_expansion() {
+        check(
+            r#"
+macro_rules! bar {
+    () => { fn  b() {} }
+}
+macro_rules! foo {
+    () => { bar!(); }
+}
+macro_rules! baz {
+    () => { foo!(); }
+}
+f<|>oo!();
+"#,
+            expect![[r#"
+                foo
+                fn b(){}
+            "#]],
+        );
+    }
+
+    #[test]
+    fn macro_expand_multiple_lines() {
+        check(
+            r#"
+macro_rules! foo {
+    () => {
+        fn some_thing() -> u32 {
+            let a = 0;
+            a + 10
+        }
+    }
+}
+f<|>oo!();
+        "#,
+            expect![[r#"
+            foo
+            fn some_thing() -> u32 {
+              let a = 0;
+              a+10
+            }"#]],
+        );
+    }
+
+    #[test]
+    fn macro_expand_match_ast() {
+        check(
+            r#"
+macro_rules! match_ast {
+    (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+    (match ($node:expr) {
+        $( ast::$ast:ident($it:ident) => $res:block, )*
+        _ => $catch_all:expr $(,)?
+    }) => {{
+        $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
+        { $catch_all }
+    }};
+}
+
+fn main() {
+    mat<|>ch_ast! {
+        match container {
+            ast::TraitDef(it) => {},
+            ast::ImplDef(it) => {},
+            _ => { continue },
+        }
+    }
+}
+"#,
+            expect![[r#"
+       match_ast
+       {
+         if let Some(it) = ast::TraitDef::cast(container.clone()){}
+         else if let Some(it) = ast::ImplDef::cast(container.clone()){}
+         else {
+           {
+             continue
+           }
+         }
+       }"#]],
+        );
+    }
+
+    #[test]
+    fn macro_expand_match_ast_inside_let_statement() {
+        check(
+            r#"
+macro_rules! match_ast {
+    (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+    (match ($node:expr) {}) => {{}};
+}
+
+fn main() {
+    let p = f(|it| {
+        let res = mat<|>ch_ast! { match c {}};
+        Some(res)
+    })?;
+}
+"#,
+            expect![[r#"
+                match_ast
+                {}
+            "#]],
+        );
+    }
+
+    #[test]
+    fn macro_expand_inner_macro_fail_to_expand() {
+        check(
+            r#"
+macro_rules! bar {
+    (BAD) => {};
+}
+macro_rules! foo {
+    () => {bar!()};
+}
+
+fn main() {
+    let res = fo<|>o!();
+}
+"#,
+            expect![[r#"
+                foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn macro_expand_with_dollar_crate() {
+        check(
+            r#"
+#[macro_export]
+macro_rules! bar {
+    () => {0};
+}
+macro_rules! foo {
+    () => {$crate::bar!()};
+}
+
+fn main() {
+    let res = fo<|>o!();
+}
+"#,
+            expect![[r#"
+                foo
+                0 "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/extend_selection.rs b/crates/ide/src/extend_selection.rs
new file mode 100644
index 000000000..34563a026
--- /dev/null
+++ b/crates/ide/src/extend_selection.rs
@@ -0,0 +1,654 @@
+use std::iter::successors;
+
+use hir::Semantics;
+use ide_db::RootDatabase;
+use syntax::{
+    algo::{self, find_covering_element, skip_trivia_token},
+    ast::{self, AstNode, AstToken},
+    Direction, NodeOrToken,
+    SyntaxKind::{self, *},
+    SyntaxNode, SyntaxToken, TextRange, TextSize, TokenAtOffset, T,
+};
+
+use crate::FileRange;
+
+// Feature: Extend Selection
+//
+// Extends the current selection to the encompassing syntactic construct
+// (expression, statement, item, module, etc). It works with multiple cursors.
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[Ctrl+Shift+→]
+// |===
+pub(crate) fn extend_selection(db: &RootDatabase, frange: FileRange) -> TextRange {
+    let sema = Semantics::new(db);
+    let src = sema.parse(frange.file_id);
+    try_extend_selection(&sema, src.syntax(), frange).unwrap_or(frange.range)
+}
+
+fn try_extend_selection(
+    sema: &Semantics<RootDatabase>,
+    root: &SyntaxNode,
+    frange: FileRange,
+) -> Option<TextRange> {
+    let range = frange.range;
+
+    let string_kinds = [COMMENT, STRING, RAW_STRING, BYTE_STRING, RAW_BYTE_STRING];
+    let list_kinds = [
+        RECORD_PAT_FIELD_LIST,
+        MATCH_ARM_LIST,
+        RECORD_FIELD_LIST,
+        TUPLE_FIELD_LIST,
+        RECORD_EXPR_FIELD_LIST,
+        VARIANT_LIST,
+        USE_TREE_LIST,
+        GENERIC_PARAM_LIST,
+        GENERIC_ARG_LIST,
+        TYPE_BOUND_LIST,
+        PARAM_LIST,
+        ARG_LIST,
+        ARRAY_EXPR,
+        TUPLE_EXPR,
+        TUPLE_TYPE,
+        TUPLE_PAT,
+        WHERE_CLAUSE,
+    ];
+
+    if range.is_empty() {
+        let offset = range.start();
+        let mut leaves = root.token_at_offset(offset);
+        if leaves.clone().all(|it| it.kind() == WHITESPACE) {
+            return Some(extend_ws(root, leaves.next()?, offset));
+        }
+        let leaf_range = match leaves {
+            TokenAtOffset::None => return None,
+            TokenAtOffset::Single(l) => {
+                if string_kinds.contains(&l.kind()) {
+                    extend_single_word_in_comment_or_string(&l, offset)
+                        .unwrap_or_else(|| l.text_range())
+                } else {
+                    l.text_range()
+                }
+            }
+            TokenAtOffset::Between(l, r) => pick_best(l, r).text_range(),
+        };
+        return Some(leaf_range);
+    };
+    let node = match find_covering_element(root, range) {
+        NodeOrToken::Token(token) => {
+            if token.text_range() != range {
+                return Some(token.text_range());
+            }
+            if let Some(comment) = ast::Comment::cast(token.clone()) {
+                if let Some(range) = extend_comments(comment) {
+                    return Some(range);
+                }
+            }
+            token.parent()
+        }
+        NodeOrToken::Node(node) => node,
+    };
+
+    // if we are in single token_tree, we maybe live in macro or attr
+    if node.kind() == TOKEN_TREE {
+        if let Some(macro_call) = node.ancestors().find_map(ast::MacroCall::cast) {
+            if let Some(range) = extend_tokens_from_range(sema, macro_call, range) {
+                return Some(range);
+            }
+        }
+    }
+
+    if node.text_range() != range {
+        return Some(node.text_range());
+    }
+
+    let node = shallowest_node(&node);
+
+    if node.parent().map(|n| list_kinds.contains(&n.kind())) == Some(true) {
+        if let Some(range) = extend_list_item(&node) {
+            return Some(range);
+        }
+    }
+
+    node.parent().map(|it| it.text_range())
+}
+
+fn extend_tokens_from_range(
+    sema: &Semantics<RootDatabase>,
+    macro_call: ast::MacroCall,
+    original_range: TextRange,
+) -> Option<TextRange> {
+    let src = find_covering_element(&macro_call.syntax(), original_range);
+    let (first_token, last_token) = match src {
+        NodeOrToken::Node(it) => (it.first_token()?, it.last_token()?),
+        NodeOrToken::Token(it) => (it.clone(), it),
+    };
+
+    let mut first_token = skip_trivia_token(first_token, Direction::Next)?;
+    let mut last_token = skip_trivia_token(last_token, Direction::Prev)?;
+
+    while !original_range.contains_range(first_token.text_range()) {
+        first_token = skip_trivia_token(first_token.next_token()?, Direction::Next)?;
+    }
+    while !original_range.contains_range(last_token.text_range()) {
+        last_token = skip_trivia_token(last_token.prev_token()?, Direction::Prev)?;
+    }
+
+    // compute original mapped token range
+    let extended = {
+        let fst_expanded = sema.descend_into_macros(first_token.clone());
+        let lst_expanded = sema.descend_into_macros(last_token.clone());
+        let mut lca = algo::least_common_ancestor(&fst_expanded.parent(), &lst_expanded.parent())?;
+        lca = shallowest_node(&lca);
+        if lca.first_token() == Some(fst_expanded) && lca.last_token() == Some(lst_expanded) {
+            lca = lca.parent()?;
+        }
+        lca
+    };
+
+    // Compute parent node range
+    let validate = |token: &SyntaxToken| {
+        let expanded = sema.descend_into_macros(token.clone());
+        algo::least_common_ancestor(&extended, &expanded.parent()).as_ref() == Some(&extended)
+    };
+
+    // Find the first and last text range under expanded parent
+    let first = successors(Some(first_token), |token| {
+        let token = token.prev_token()?;
+        skip_trivia_token(token, Direction::Prev)
+    })
+    .take_while(validate)
+    .last()?;
+
+    let last = successors(Some(last_token), |token| {
+        let token = token.next_token()?;
+        skip_trivia_token(token, Direction::Next)
+    })
+    .take_while(validate)
+    .last()?;
+
+    let range = first.text_range().cover(last.text_range());
+    if range.contains_range(original_range) && original_range != range {
+        Some(range)
+    } else {
+        None
+    }
+}
+
+/// Find the shallowest node with same range, which allows us to traverse siblings.
+fn shallowest_node(node: &SyntaxNode) -> SyntaxNode {
+    node.ancestors().take_while(|n| n.text_range() == node.text_range()).last().unwrap()
+}
+
+fn extend_single_word_in_comment_or_string(
+    leaf: &SyntaxToken,
+    offset: TextSize,
+) -> Option<TextRange> {
+    let text: &str = leaf.text();
+    let cursor_position: u32 = (offset - leaf.text_range().start()).into();
+
+    let (before, after) = text.split_at(cursor_position as usize);
+
+    fn non_word_char(c: char) -> bool {
+        !(c.is_alphanumeric() || c == '_')
+    }
+
+    let start_idx = before.rfind(non_word_char)? as u32;
+    let end_idx = after.find(non_word_char).unwrap_or_else(|| after.len()) as u32;
+
+    let from: TextSize = (start_idx + 1).into();
+    let to: TextSize = (cursor_position + end_idx).into();
+
+    let range = TextRange::new(from, to);
+    if range.is_empty() {
+        None
+    } else {
+        Some(range + leaf.text_range().start())
+    }
+}
+
+fn extend_ws(root: &SyntaxNode, ws: SyntaxToken, offset: TextSize) -> TextRange {
+    let ws_text = ws.text();
+    let suffix = TextRange::new(offset, ws.text_range().end()) - ws.text_range().start();
+    let prefix = TextRange::new(ws.text_range().start(), offset) - ws.text_range().start();
+    let ws_suffix = &ws_text.as_str()[suffix];
+    let ws_prefix = &ws_text.as_str()[prefix];
+    if ws_text.contains('\n') && !ws_suffix.contains('\n') {
+        if let Some(node) = ws.next_sibling_or_token() {
+            let start = match ws_prefix.rfind('\n') {
+                Some(idx) => ws.text_range().start() + TextSize::from((idx + 1) as u32),
+                None => node.text_range().start(),
+            };
+            let end = if root.text().char_at(node.text_range().end()) == Some('\n') {
+                node.text_range().end() + TextSize::of('\n')
+            } else {
+                node.text_range().end()
+            };
+            return TextRange::new(start, end);
+        }
+    }
+    ws.text_range()
+}
+
+fn pick_best(l: SyntaxToken, r: SyntaxToken) -> SyntaxToken {
+    return if priority(&r) > priority(&l) { r } else { l };
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            WHITESPACE => 0,
+            IDENT | T![self] | T![super] | T![crate] | LIFETIME => 2,
+            _ => 1,
+        }
+    }
+}
+
+/// Extend list item selection to include nearby delimiter and whitespace.
+fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
+    fn is_single_line_ws(node: &SyntaxToken) -> bool {
+        node.kind() == WHITESPACE && !node.text().contains('\n')
+    }
+
+    fn nearby_delimiter(
+        delimiter_kind: SyntaxKind,
+        node: &SyntaxNode,
+        dir: Direction,
+    ) -> Option<SyntaxToken> {
+        node.siblings_with_tokens(dir)
+            .skip(1)
+            .skip_while(|node| match node {
+                NodeOrToken::Node(_) => false,
+                NodeOrToken::Token(it) => is_single_line_ws(it),
+            })
+            .next()
+            .and_then(|it| it.into_token())
+            .filter(|node| node.kind() == delimiter_kind)
+    }
+
+    let delimiter = match node.kind() {
+        TYPE_BOUND => T![+],
+        _ => T![,],
+    };
+
+    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Next) {
+        // Include any following whitespace when delimiter is after list item.
+        let final_node = delimiter_node
+            .next_sibling_or_token()
+            .and_then(|it| it.into_token())
+            .filter(|node| is_single_line_ws(node))
+            .unwrap_or(delimiter_node);
+
+        return Some(TextRange::new(node.text_range().start(), final_node.text_range().end()));
+    }
+    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Prev) {
+        return Some(TextRange::new(delimiter_node.text_range().start(), node.text_range().end()));
+    }
+
+    None
+}
+
+fn extend_comments(comment: ast::Comment) -> Option<TextRange> {
+    let prev = adj_comments(&comment, Direction::Prev);
+    let next = adj_comments(&comment, Direction::Next);
+    if prev != next {
+        Some(TextRange::new(prev.syntax().text_range().start(), next.syntax().text_range().end()))
+    } else {
+        None
+    }
+}
+
+fn adj_comments(comment: &ast::Comment, dir: Direction) -> ast::Comment {
+    let mut res = comment.clone();
+    for element in comment.syntax().siblings_with_tokens(dir) {
+        let token = match element.as_token() {
+            None => break,
+            Some(token) => token,
+        };
+        if let Some(c) = ast::Comment::cast(token.clone()) {
+            res = c
+        } else if token.kind() != WHITESPACE || token.text().contains("\n\n") {
+            break;
+        }
+    }
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::analysis_and_position;
+
+    use super::*;
+
+    fn do_check(before: &str, afters: &[&str]) {
+        let (analysis, position) = analysis_and_position(&before);
+        let before = analysis.file_text(position.file_id).unwrap();
+        let range = TextRange::empty(position.offset);
+        let mut frange = FileRange { file_id: position.file_id, range };
+
+        for &after in afters {
+            frange.range = analysis.extend_selection(frange).unwrap();
+            let actual = &before[frange.range];
+            assert_eq!(after, actual);
+        }
+    }
+
+    #[test]
+    fn test_extend_selection_arith() {
+        do_check(r#"fn foo() { <|>1 + 1 }"#, &["1", "1 + 1", "{ 1 + 1 }"]);
+    }
+
+    #[test]
+    fn test_extend_selection_list() {
+        do_check(r#"fn foo(<|>x: i32) {}"#, &["x", "x: i32"]);
+        do_check(r#"fn foo(<|>x: i32, y: i32) {}"#, &["x", "x: i32", "x: i32, "]);
+        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,", "(x: i32,y: i32)"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32) {}"#, &["y", "y: i32", ", y: i32"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", "y: i32, "]);
+        do_check(r#"fn foo(x: i32,<|>y: i32) {}"#, &["y", "y: i32", ",y: i32"]);
+
+        do_check(r#"const FOO: [usize; 2] = [ 22<|> , 33];"#, &["22", "22 , "]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|>];"#, &["33", ", 33"]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", "33 ,", "[ 22 , 33 ,]"]);
+
+        do_check(r#"fn main() { (1, 2<|>) }"#, &["2", ", 2", "(1, 2)"]);
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22,
+    <|>33,
+]"#,
+            &["33", "33,"],
+        );
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22
+    , 33<|>,
+]"#,
+            &["33", "33,"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_start_of_the_line() {
+        do_check(
+            r#"
+impl S {
+<|>    fn foo() {
+
+    }
+}"#,
+            &["    fn foo() {\n\n    }\n"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_doc_comments() {
+        do_check(
+            r#"
+struct A;
+
+/// bla
+/// bla
+struct B {
+    <|>
+}
+            "#,
+            &["\n    \n", "{\n    \n}", "/// bla\n/// bla\nstruct B {\n    \n}"],
+        )
+    }
+
+    #[test]
+    fn test_extend_selection_comments() {
+        do_check(
+            r#"
+fn bar(){}
+
+// fn foo() {
+// 1 + <|>1
+// }
+
+// fn foo(){}
+    "#,
+            &["1", "// 1 + 1", "// fn foo() {\n// 1 + 1\n// }"],
+        );
+
+        do_check(
+            r#"
+// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+// pub enum Direction {
+//  <|>   Next,
+//     Prev
+// }
+"#,
+            &[
+                "//     Next,",
+                "// #[derive(Debug, Clone, Copy, PartialEq, Eq)]\n// pub enum Direction {\n//     Next,\n//     Prev\n// }",
+            ],
+        );
+
+        do_check(
+            r#"
+/*
+foo
+_bar1<|>*/
+"#,
+            &["_bar1", "/*\nfoo\n_bar1*/"],
+        );
+
+        do_check(r#"//!<|>foo_2 bar"#, &["foo_2", "//!foo_2 bar"]);
+
+        do_check(r#"/<|>/foo bar"#, &["//foo bar"]);
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_idents() {
+        do_check(
+            r#"
+fn main() { foo<|>+bar;}
+"#,
+            &["foo", "foo+bar"],
+        );
+        do_check(
+            r#"
+fn main() { foo+<|>bar;}
+"#,
+            &["bar", "foo+bar"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_lifetimes() {
+        do_check(r#"fn foo<<|>'a>() {}"#, &["'a", "<'a>"]);
+        do_check(r#"fn foo<'a<|>>() {}"#, &["'a", "<'a>"]);
+    }
+
+    #[test]
+    fn test_extend_selection_select_first_word() {
+        do_check(r#"// foo bar b<|>az quxx"#, &["baz", "// foo bar baz quxx"]);
+        do_check(
+            r#"
+impl S {
+fn foo() {
+// hel<|>lo world
+}
+}
+"#,
+            &["hello", "// hello world"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_string() {
+        do_check(
+            r#"
+fn bar(){}
+
+" fn f<|>oo() {"
+"#,
+            &["foo", "\" fn foo() {\""],
+        );
+    }
+
+    #[test]
+    fn test_extend_trait_bounds_list_in_where_clause() {
+        do_check(
+            r#"
+fn foo<R>()
+    where
+        R: req::Request + 'static,
+        R::Params: DeserializeOwned<|> + panic::UnwindSafe + 'static,
+        R::Result: Serialize + 'static,
+"#,
+            &[
+                "DeserializeOwned",
+                "DeserializeOwned + ",
+                "DeserializeOwned + panic::UnwindSafe + 'static",
+                "R::Params: DeserializeOwned + panic::UnwindSafe + 'static",
+                "R::Params: DeserializeOwned + panic::UnwindSafe + 'static,",
+            ],
+        );
+        do_check(r#"fn foo<T>() where T: <|>Copy"#, &["Copy"]);
+        do_check(r#"fn foo<T>() where T: <|>Copy + Display"#, &["Copy", "Copy + "]);
+        do_check(r#"fn foo<T>() where T: <|>Copy +Display"#, &["Copy", "Copy +"]);
+        do_check(r#"fn foo<T>() where T: <|>Copy+Display"#, &["Copy", "Copy+"]);
+        do_check(r#"fn foo<T>() where T: Copy + <|>Display"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T>() where T: Copy + <|>Display + Sync"#, &["Display", "Display + "]);
+        do_check(r#"fn foo<T>() where T: Copy +<|>Display"#, &["Display", "+Display"]);
+    }
+
+    #[test]
+    fn test_extend_trait_bounds_list_inline() {
+        do_check(r#"fn foo<T: <|>Copy>() {}"#, &["Copy"]);
+        do_check(r#"fn foo<T: <|>Copy + Display>() {}"#, &["Copy", "Copy + "]);
+        do_check(r#"fn foo<T: <|>Copy +Display>() {}"#, &["Copy", "Copy +"]);
+        do_check(r#"fn foo<T: <|>Copy+Display>() {}"#, &["Copy", "Copy+"]);
+        do_check(r#"fn foo<T: Copy + <|>Display>() {}"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T: Copy + <|>Display + Sync>() {}"#, &["Display", "Display + "]);
+        do_check(r#"fn foo<T: Copy +<|>Display>() {}"#, &["Display", "+Display"]);
+        do_check(
+            r#"fn foo<T: Copy<|> + Display, U: Copy>() {}"#,
+            &[
+                "Copy",
+                "Copy + ",
+                "Copy + Display",
+                "T: Copy + Display",
+                "T: Copy + Display, ",
+                "<T: Copy + Display, U: Copy>",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_type() {
+        do_check(
+            r#"fn main() { let _: (krate, <|>_crate_def_map, module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let _: (krate,<|>_crate_def_map,module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let _: (
+    krate,
+    _crate<|>_def_map,
+    module_id
+) = (); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_rvalue() {
+        do_check(
+            r#"fn main() { let var = (krate, _crate_def_map<|>, module_id); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let var = (krate,_crate<|>_def_map,module_id); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let var = (
+    krate,
+    _crate_def_map<|>,
+    module_id
+); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_pat() {
+        do_check(
+            r#"fn main() { let (krate, _crate_def_map<|>, module_id) = var; }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let (krate,_crate<|>_def_map,module_id) = var; }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let (
+    krate,
+    _crate_def_map<|>,
+    module_id
+) = var; }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn extend_selection_inside_macros() {
+        do_check(
+            r#"macro_rules! foo { ($item:item) => {$item} }
+                foo!{fn hello(na<|>me:usize){}}"#,
+            &[
+                "name",
+                "name:usize",
+                "(name:usize)",
+                "fn hello(name:usize){}",
+                "{fn hello(name:usize){}}",
+                "foo!{fn hello(name:usize){}}",
+            ],
+        );
+    }
+
+    #[test]
+    fn extend_selection_inside_recur_macros() {
+        do_check(
+            r#" macro_rules! foo2 { ($item:item) => {$item} }
+                macro_rules! foo { ($item:item) => {foo2!($item);} }
+                foo!{fn hello(na<|>me:usize){}}"#,
+            &[
+                "name",
+                "name:usize",
+                "(name:usize)",
+                "fn hello(name:usize){}",
+                "{fn hello(name:usize){}}",
+                "foo!{fn hello(name:usize){}}",
+            ],
+        );
+    }
+}
diff --git a/crates/ide/src/file_structure.rs b/crates/ide/src/file_structure.rs
new file mode 100644
index 000000000..c90247ba6
--- /dev/null
+++ b/crates/ide/src/file_structure.rs
@@ -0,0 +1,431 @@
+use syntax::{
+    ast::{self, AttrsOwner, GenericParamsOwner, NameOwner},
+    match_ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange, WalkEvent,
+};
+
+#[derive(Debug, Clone)]
+pub struct StructureNode {
+    pub parent: Option<usize>,
+    pub label: String,
+    pub navigation_range: TextRange,
+    pub node_range: TextRange,
+    pub kind: SyntaxKind,
+    pub detail: Option<String>,
+    pub deprecated: bool,
+}
+
+// Feature: File Structure
+//
+// Provides a tree of the symbols defined in the file. Can be used to
+//
+// * fuzzy search symbol in a file (super useful)
+// * draw breadcrumbs to describe the context around the cursor
+// * draw outline of the file
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[Ctrl+Shift+O]
+// |===
+pub fn file_structure(file: &SourceFile) -> Vec<StructureNode> {
+    let mut res = Vec::new();
+    let mut stack = Vec::new();
+
+    for event in file.syntax().preorder() {
+        match event {
+            WalkEvent::Enter(node) => {
+                if let Some(mut symbol) = structure_node(&node) {
+                    symbol.parent = stack.last().copied();
+                    stack.push(res.len());
+                    res.push(symbol);
+                }
+            }
+            WalkEvent::Leave(node) => {
+                if structure_node(&node).is_some() {
+                    stack.pop().unwrap();
+                }
+            }
+        }
+    }
+    res
+}
+
+fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
+    fn decl<N: NameOwner + AttrsOwner>(node: N) -> Option<StructureNode> {
+        decl_with_detail(&node, None)
+    }
+
+    fn decl_with_type_ref<N: NameOwner + AttrsOwner>(
+        node: &N,
+        type_ref: Option<ast::Type>,
+    ) -> Option<StructureNode> {
+        let detail = type_ref.map(|type_ref| {
+            let mut detail = String::new();
+            collapse_ws(type_ref.syntax(), &mut detail);
+            detail
+        });
+        decl_with_detail(node, detail)
+    }
+
+    fn decl_with_detail<N: NameOwner + AttrsOwner>(
+        node: &N,
+        detail: Option<String>,
+    ) -> Option<StructureNode> {
+        let name = node.name()?;
+
+        Some(StructureNode {
+            parent: None,
+            label: name.text().to_string(),
+            navigation_range: name.syntax().text_range(),
+            node_range: node.syntax().text_range(),
+            kind: node.syntax().kind(),
+            detail,
+            deprecated: node.attrs().filter_map(|x| x.simple_name()).any(|x| x == "deprecated"),
+        })
+    }
+
+    fn collapse_ws(node: &SyntaxNode, output: &mut String) {
+        let mut can_insert_ws = false;
+        node.text().for_each_chunk(|chunk| {
+            for line in chunk.lines() {
+                let line = line.trim();
+                if line.is_empty() {
+                    if can_insert_ws {
+                        output.push(' ');
+                        can_insert_ws = false;
+                    }
+                } else {
+                    output.push_str(line);
+                    can_insert_ws = true;
+                }
+            }
+        })
+    }
+
+    match_ast! {
+        match node {
+            ast::Fn(it) => {
+                let mut detail = String::from("fn");
+                if let Some(type_param_list) = it.generic_param_list() {
+                    collapse_ws(type_param_list.syntax(), &mut detail);
+                }
+                if let Some(param_list) = it.param_list() {
+                    collapse_ws(param_list.syntax(), &mut detail);
+                }
+                if let Some(ret_type) = it.ret_type() {
+                    detail.push_str(" ");
+                    collapse_ws(ret_type.syntax(), &mut detail);
+                }
+
+                decl_with_detail(&it, Some(detail))
+            },
+            ast::Struct(it) => decl(it),
+            ast::Union(it) => decl(it),
+            ast::Enum(it) => decl(it),
+            ast::Variant(it) => decl(it),
+            ast::Trait(it) => decl(it),
+            ast::Module(it) => decl(it),
+            ast::TypeAlias(it) => decl_with_type_ref(&it, it.ty()),
+            ast::RecordField(it) => decl_with_type_ref(&it, it.ty()),
+            ast::Const(it) => decl_with_type_ref(&it, it.ty()),
+            ast::Static(it) => decl_with_type_ref(&it, it.ty()),
+            ast::Impl(it) => {
+                let target_type = it.self_ty()?;
+                let target_trait = it.trait_();
+                let label = match target_trait {
+                    None => format!("impl {}", target_type.syntax().text()),
+                    Some(t) => {
+                        format!("impl {} for {}", t.syntax().text(), target_type.syntax().text(),)
+                    }
+                };
+
+                let node = StructureNode {
+                    parent: None,
+                    label,
+                    navigation_range: target_type.syntax().text_range(),
+                    node_range: it.syntax().text_range(),
+                    kind: it.syntax().kind(),
+                    detail: None,
+                    deprecated: false,
+                };
+                Some(node)
+            },
+            ast::MacroCall(it) => {
+                match it.path().and_then(|it| it.segment()).and_then(|it| it.name_ref()) {
+                    Some(path_segment) if path_segment.text() == "macro_rules"
+                    => decl(it),
+                    _ => None,
+                }
+            },
+            _ => None,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use super::*;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let file = SourceFile::parse(ra_fixture).ok().unwrap();
+        let structure = file_structure(&file);
+        expect.assert_debug_eq(&structure)
+    }
+
+    #[test]
+    fn test_file_structure() {
+        check(
+            r#"
+struct Foo {
+    x: i32
+}
+
+mod m {
+    fn bar1() {}
+    fn bar2<T>(t: T) -> T {}
+    fn bar3<A,
+        B>(a: A,
+        b: B) -> Vec<
+        u32
+    > {}
+}
+
+enum E { X, Y(i32) }
+type T = ();
+static S: i32 = 92;
+const C: i32 = 92;
+
+impl E {}
+
+impl fmt::Debug for E {}
+
+macro_rules! mc {
+    () => {}
+}
+
+#[macro_export]
+macro_rules! mcexp {
+    () => {}
+}
+
+/// Doc comment
+macro_rules! mcexp {
+    () => {}
+}
+
+#[deprecated]
+fn obsolete() {}
+
+#[deprecated(note = "for awhile")]
+fn very_obsolete() {}
+"#,
+            expect![[r#"
+                [
+                    StructureNode {
+                        parent: None,
+                        label: "Foo",
+                        navigation_range: 8..11,
+                        node_range: 1..26,
+                        kind: STRUCT,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            0,
+                        ),
+                        label: "x",
+                        navigation_range: 18..19,
+                        node_range: 18..24,
+                        kind: RECORD_FIELD,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "m",
+                        navigation_range: 32..33,
+                        node_range: 28..158,
+                        kind: MODULE,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar1",
+                        navigation_range: 43..47,
+                        node_range: 40..52,
+                        kind: FN,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar2",
+                        navigation_range: 60..64,
+                        node_range: 57..81,
+                        kind: FN,
+                        detail: Some(
+                            "fn<T>(t: T) -> T",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar3",
+                        navigation_range: 89..93,
+                        node_range: 86..156,
+                        kind: FN,
+                        detail: Some(
+                            "fn<A, B>(a: A, b: B) -> Vec< u32 >",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "E",
+                        navigation_range: 165..166,
+                        node_range: 160..180,
+                        kind: ENUM,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            6,
+                        ),
+                        label: "X",
+                        navigation_range: 169..170,
+                        node_range: 169..170,
+                        kind: VARIANT,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            6,
+                        ),
+                        label: "Y",
+                        navigation_range: 172..173,
+                        node_range: 172..178,
+                        kind: VARIANT,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "T",
+                        navigation_range: 186..187,
+                        node_range: 181..193,
+                        kind: TYPE_ALIAS,
+                        detail: Some(
+                            "()",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "S",
+                        navigation_range: 201..202,
+                        node_range: 194..213,
+                        kind: STATIC,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "C",
+                        navigation_range: 220..221,
+                        node_range: 214..232,
+                        kind: CONST,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "impl E",
+                        navigation_range: 239..240,
+                        node_range: 234..243,
+                        kind: IMPL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "impl fmt::Debug for E",
+                        navigation_range: 265..266,
+                        node_range: 245..269,
+                        kind: IMPL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mc",
+                        navigation_range: 284..286,
+                        node_range: 271..303,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mcexp",
+                        navigation_range: 334..339,
+                        node_range: 305..356,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mcexp",
+                        navigation_range: 387..392,
+                        node_range: 358..409,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "obsolete",
+                        navigation_range: 428..436,
+                        node_range: 411..441,
+                        kind: FN,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: true,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "very_obsolete",
+                        navigation_range: 481..494,
+                        node_range: 443..499,
+                        kind: FN,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: true,
+                    },
+                ]
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/folding_ranges.rs b/crates/ide/src/folding_ranges.rs
new file mode 100644
index 000000000..7523aec55
--- /dev/null
+++ b/crates/ide/src/folding_ranges.rs
@@ -0,0 +1,422 @@
+//! FIXME: write short doc here
+
+use rustc_hash::FxHashSet;
+
+use syntax::{
+    ast::{self, AstNode, AstToken, VisibilityOwner},
+    Direction, NodeOrToken, SourceFile,
+    SyntaxKind::{self, *},
+    SyntaxNode, TextRange,
+};
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum FoldKind {
+    Comment,
+    Imports,
+    Mods,
+    Block,
+    ArgList,
+}
+
+#[derive(Debug)]
+pub struct Fold {
+    pub range: TextRange,
+    pub kind: FoldKind,
+}
+
+pub(crate) fn folding_ranges(file: &SourceFile) -> Vec<Fold> {
+    let mut res = vec![];
+    let mut visited_comments = FxHashSet::default();
+    let mut visited_imports = FxHashSet::default();
+    let mut visited_mods = FxHashSet::default();
+
+    for element in file.syntax().descendants_with_tokens() {
+        // Fold items that span multiple lines
+        if let Some(kind) = fold_kind(element.kind()) {
+            let is_multiline = match &element {
+                NodeOrToken::Node(node) => node.text().contains_char('\n'),
+                NodeOrToken::Token(token) => token.text().contains('\n'),
+            };
+            if is_multiline {
+                res.push(Fold { range: element.text_range(), kind });
+                continue;
+            }
+        }
+
+        match element {
+            NodeOrToken::Token(token) => {
+                // Fold groups of comments
+                if let Some(comment) = ast::Comment::cast(token) {
+                    if !visited_comments.contains(&comment) {
+                        if let Some(range) =
+                            contiguous_range_for_comment(comment, &mut visited_comments)
+                        {
+                            res.push(Fold { range, kind: FoldKind::Comment })
+                        }
+                    }
+                }
+            }
+            NodeOrToken::Node(node) => {
+                // Fold groups of imports
+                if node.kind() == USE && !visited_imports.contains(&node) {
+                    if let Some(range) = contiguous_range_for_group(&node, &mut visited_imports) {
+                        res.push(Fold { range, kind: FoldKind::Imports })
+                    }
+                }
+
+                // Fold groups of mods
+                if node.kind() == MODULE && !has_visibility(&node) && !visited_mods.contains(&node)
+                {
+                    if let Some(range) =
+                        contiguous_range_for_group_unless(&node, has_visibility, &mut visited_mods)
+                    {
+                        res.push(Fold { range, kind: FoldKind::Mods })
+                    }
+                }
+            }
+        }
+    }
+
+    res
+}
+
+fn fold_kind(kind: SyntaxKind) -> Option<FoldKind> {
+    match kind {
+        COMMENT => Some(FoldKind::Comment),
+        USE => Some(FoldKind::Imports),
+        ARG_LIST | PARAM_LIST => Some(FoldKind::ArgList),
+        ASSOC_ITEM_LIST
+        | RECORD_FIELD_LIST
+        | RECORD_PAT_FIELD_LIST
+        | RECORD_EXPR_FIELD_LIST
+        | ITEM_LIST
+        | EXTERN_ITEM_LIST
+        | USE_TREE_LIST
+        | BLOCK_EXPR
+        | MATCH_ARM_LIST
+        | VARIANT_LIST
+        | TOKEN_TREE => Some(FoldKind::Block),
+        _ => None,
+    }
+}
+
+fn has_visibility(node: &SyntaxNode) -> bool {
+    ast::Module::cast(node.clone()).and_then(|m| m.visibility()).is_some()
+}
+
+fn contiguous_range_for_group(
+    first: &SyntaxNode,
+    visited: &mut FxHashSet<SyntaxNode>,
+) -> Option<TextRange> {
+    contiguous_range_for_group_unless(first, |_| false, visited)
+}
+
+fn contiguous_range_for_group_unless(
+    first: &SyntaxNode,
+    unless: impl Fn(&SyntaxNode) -> bool,
+    visited: &mut FxHashSet<SyntaxNode>,
+) -> Option<TextRange> {
+    visited.insert(first.clone());
+
+    let mut last = first.clone();
+    for element in first.siblings_with_tokens(Direction::Next) {
+        let node = match element {
+            NodeOrToken::Token(token) => {
+                if let Some(ws) = ast::Whitespace::cast(token) {
+                    if !ws.spans_multiple_lines() {
+                        // Ignore whitespace without blank lines
+                        continue;
+                    }
+                }
+                // There is a blank line or another token, which means that the
+                // group ends here
+                break;
+            }
+            NodeOrToken::Node(node) => node,
+        };
+
+        // Stop if we find a node that doesn't belong to the group
+        if node.kind() != first.kind() || unless(&node) {
+            break;
+        }
+
+        visited.insert(node.clone());
+        last = node;
+    }
+
+    if first != &last {
+        Some(TextRange::new(first.text_range().start(), last.text_range().end()))
+    } else {
+        // The group consists of only one element, therefore it cannot be folded
+        None
+    }
+}
+
+fn contiguous_range_for_comment(
+    first: ast::Comment,
+    visited: &mut FxHashSet<ast::Comment>,
+) -> Option<TextRange> {
+    visited.insert(first.clone());
+
+    // Only fold comments of the same flavor
+    let group_kind = first.kind();
+    if !group_kind.shape.is_line() {
+        return None;
+    }
+
+    let mut last = first.clone();
+    for element in first.syntax().siblings_with_tokens(Direction::Next) {
+        match element {
+            NodeOrToken::Token(token) => {
+                if let Some(ws) = ast::Whitespace::cast(token.clone()) {
+                    if !ws.spans_multiple_lines() {
+                        // Ignore whitespace without blank lines
+                        continue;
+                    }
+                }
+                if let Some(c) = ast::Comment::cast(token) {
+                    if c.kind() == group_kind {
+                        visited.insert(c.clone());
+                        last = c;
+                        continue;
+                    }
+                }
+                // The comment group ends because either:
+                // * An element of a different kind was reached
+                // * A comment of a different flavor was reached
+                break;
+            }
+            NodeOrToken::Node(_) => break,
+        };
+    }
+
+    if first != last {
+        Some(TextRange::new(first.syntax().text_range().start(), last.syntax().text_range().end()))
+    } else {
+        // The group consists of only one element, therefore it cannot be folded
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use test_utils::extract_tags;
+
+    use super::*;
+
+    fn check(ra_fixture: &str) {
+        let (ranges, text) = extract_tags(ra_fixture, "fold");
+
+        let parse = SourceFile::parse(&text);
+        let folds = folding_ranges(&parse.tree());
+        assert_eq!(
+            folds.len(),
+            ranges.len(),
+            "The amount of folds is different than the expected amount"
+        );
+
+        for (fold, (range, attr)) in folds.iter().zip(ranges.into_iter()) {
+            assert_eq!(fold.range.start(), range.start());
+            assert_eq!(fold.range.end(), range.end());
+
+            let kind = match fold.kind {
+                FoldKind::Comment => "comment",
+                FoldKind::Imports => "imports",
+                FoldKind::Mods => "mods",
+                FoldKind::Block => "block",
+                FoldKind::ArgList => "arglist",
+            };
+            assert_eq!(kind, &attr.unwrap());
+        }
+    }
+
+    #[test]
+    fn test_fold_comments() {
+        check(
+            r#"
+<fold comment>// Hello
+// this is a multiline
+// comment
+//</fold>
+
+// But this is not
+
+fn main() <fold block>{
+    <fold comment>// We should
+    // also
+    // fold
+    // this one.</fold>
+    <fold comment>//! But this one is different
+    //! because it has another flavor</fold>
+    <fold comment>/* As does this
+    multiline comment */</fold>
+}</fold>"#,
+        );
+    }
+
+    #[test]
+    fn test_fold_imports() {
+        check(
+            r#"
+<fold imports>use std::<fold block>{
+    str,
+    vec,
+    io as iop
+}</fold>;</fold>
+
+fn main() <fold block>{
+}</fold>"#,
+        );
+    }
+
+    #[test]
+    fn test_fold_mods() {
+        check(
+            r#"
+
+pub mod foo;
+<fold mods>mod after_pub;
+mod after_pub_next;</fold>
+
+<fold mods>mod before_pub;
+mod before_pub_next;</fold>
+pub mod bar;
+
+mod not_folding_single;
+pub mod foobar;
+pub not_folding_single_next;
+
+<fold mods>#[cfg(test)]
+mod with_attribute;
+mod with_attribute_next;</fold>
+
+fn main() <fold block>{
+}</fold>"#,
+        );
+    }
+
+    #[test]
+    fn test_fold_import_groups() {
+        check(
+            r#"
+<fold imports>use std::str;
+use std::vec;
+use std::io as iop;</fold>
+
+<fold imports>use std::mem;
+use std::f64;</fold>
+
+use std::collections::HashMap;
+// Some random comment
+use std::collections::VecDeque;
+
+fn main() <fold block>{
+}</fold>"#,
+        );
+    }
+
+    #[test]
+    fn test_fold_import_and_groups() {
+        check(
+            r#"
+<fold imports>use std::str;
+use std::vec;
+use std::io as iop;</fold>
+
+<fold imports>use std::mem;
+use std::f64;</fold>
+
+<fold imports>use std::collections::<fold block>{
+    HashMap,
+    VecDeque,
+}</fold>;</fold>
+// Some random comment
+
+fn main() <fold block>{
+}</fold>"#,
+        );
+    }
+
+    #[test]
+    fn test_folds_structs() {
+        check(
+            r#"
+struct Foo <fold block>{
+}</fold>
+"#,
+        );
+    }
+
+    #[test]
+    fn test_folds_traits() {
+        check(
+            r#"
+trait Foo <fold block>{
+}</fold>
+"#,
+        );
+    }
+
+    #[test]
+    fn test_folds_macros() {
+        check(
+            r#"
+macro_rules! foo <fold block>{
+    ($($tt:tt)*) => { $($tt)* }
+}</fold>
+"#,
+        );
+    }
+
+    #[test]
+    fn test_fold_match_arms() {
+        check(
+            r#"
+fn main() <fold block>{
+    match 0 <fold block>{
+        0 => 0,
+        _ => 1,
+    }</fold>
+}</fold>
+"#,
+        );
+    }
+
+    #[test]
+    fn fold_big_calls() {
+        check(
+            r#"
+fn main() <fold block>{
+    frobnicate<fold arglist>(
+        1,
+        2,
+        3,
+    )</fold>
+}</fold>
+"#,
+        )
+    }
+
+    #[test]
+    fn fold_record_literals() {
+        check(
+            r#"
+const _: S = S <fold block>{
+
+}</fold>;
+"#,
+        )
+    }
+
+    #[test]
+    fn fold_multiline_params() {
+        check(
+            r#"
+fn foo<fold arglist>(
+    x: i32,
+    y: String,
+)</fold> {}
+"#,
+        )
+    }
+}
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
new file mode 100644
index 000000000..15e9b7fad
--- /dev/null
+++ b/crates/ide/src/goto_definition.rs
@@ -0,0 +1,989 @@
+use hir::Semantics;
+use ide_db::{
+    defs::{classify_name, classify_name_ref},
+    symbol_index, RootDatabase,
+};
+use syntax::{
+    ast::{self},
+    match_ast, AstNode,
+    SyntaxKind::*,
+    SyntaxToken, TokenAtOffset, T,
+};
+
+use crate::{
+    display::{ToNav, TryToNav},
+    FilePosition, NavigationTarget, RangeInfo,
+};
+
+// Feature: Go to Definition
+//
+// Navigates to the definition of an identifier.
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[F12]
+// |===
+pub(crate) fn goto_definition(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let sema = Semantics::new(db);
+    let file = sema.parse(position.file_id).syntax().clone();
+    let original_token = pick_best(file.token_at_offset(position.offset))?;
+    let token = sema.descend_into_macros(original_token.clone());
+    let parent = token.parent();
+
+    let nav_targets = match_ast! {
+        match parent {
+            ast::NameRef(name_ref) => {
+                reference_definition(&sema, &name_ref).to_vec()
+            },
+            ast::Name(name) => {
+                let def = classify_name(&sema, &name)?.definition(sema.db);
+                let nav = def.try_to_nav(sema.db)?;
+                vec![nav]
+            },
+            _ => return None,
+        }
+    };
+
+    Some(RangeInfo::new(original_token.text_range(), nav_targets))
+}
+
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER | T![self] => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(crate) enum ReferenceResult {
+    Exact(NavigationTarget),
+    Approximate(Vec<NavigationTarget>),
+}
+
+impl ReferenceResult {
+    fn to_vec(self) -> Vec<NavigationTarget> {
+        match self {
+            ReferenceResult::Exact(target) => vec![target],
+            ReferenceResult::Approximate(vec) => vec,
+        }
+    }
+}
+
+pub(crate) fn reference_definition(
+    sema: &Semantics<RootDatabase>,
+    name_ref: &ast::NameRef,
+) -> ReferenceResult {
+    let name_kind = classify_name_ref(sema, name_ref);
+    if let Some(def) = name_kind {
+        let def = def.definition(sema.db);
+        return match def.try_to_nav(sema.db) {
+            Some(nav) => ReferenceResult::Exact(nav),
+            None => ReferenceResult::Approximate(Vec::new()),
+        };
+    }
+
+    // Fallback index based approach:
+    let navs = symbol_index::index_resolve(sema.db, name_ref)
+        .into_iter()
+        .map(|s| s.to_nav(sema.db))
+        .collect();
+    ReferenceResult::Approximate(navs)
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::FileRange;
+    use syntax::{TextRange, TextSize};
+
+    use crate::mock_analysis::MockAnalysis;
+
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let (mut expected, data) = mock.annotation();
+        let analysis = mock.analysis();
+        match data.as_str() {
+            "" => (),
+            "file" => {
+                expected.range =
+                    TextRange::up_to(TextSize::of(&*analysis.file_text(expected.file_id).unwrap()))
+            }
+            data => panic!("bad data: {}", data),
+        }
+
+        let mut navs =
+            analysis.goto_definition(position).unwrap().expect("no definition found").info;
+        if navs.len() == 0 {
+            panic!("unresolved reference")
+        }
+        assert_eq!(navs.len(), 1);
+
+        let nav = navs.pop().unwrap();
+        assert_eq!(expected, FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() });
+    }
+
+    #[test]
+    fn goto_def_for_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+
+    #[test]
+    fn goto_def_for_renamed_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std as abc<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+
+    #[test]
+    fn goto_def_in_items() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+enum E { X(Foo<|>) }
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_at_start_of_item() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+enum E { X(<|>Foo) }
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_definition_resolves_correct_name() {
+        check(
+            r#"
+//- /lib.rs
+use a::Foo;
+mod a;
+mod b;
+enum E { X(Foo<|>) }
+
+//- /a.rs
+struct Foo;
+     //^^^
+//- /b.rs
+struct Foo;
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_module_declaration() {
+        check(
+            r#"
+//- /lib.rs
+mod <|>foo;
+
+//- /foo.rs
+// empty
+//^ file
+"#,
+        );
+
+        check(
+            r#"
+//- /lib.rs
+mod <|>foo;
+
+//- /foo/mod.rs
+// empty
+//^ file
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_macros() {
+        check(
+            r#"
+macro_rules! foo { () => { () } }
+           //^^^
+fn bar() {
+    <|>foo!();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_macros_from_other_crates() {
+        check(
+            r#"
+//- /lib.rs
+use foo::foo;
+fn bar() {
+    <|>foo!();
+}
+
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_macros_in_use_tree() {
+        check(
+            r#"
+//- /lib.rs
+use foo::foo<|>;
+
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_macro_defined_fn_with_arg() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! define_fn {
+    ($name:ident) => (fn $name() {})
+}
+
+define_fn!(foo);
+         //^^^
+
+fn bar() {
+   <|>foo();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_macro_defined_fn_no_arg() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! define_fn {
+    () => (fn foo() {})
+}
+
+  define_fn!();
+//^^^^^^^^^^^^^
+
+fn bar() {
+   <|>foo();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macro_inside_pattern() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! foo {() => {0}}
+           //^^^
+
+fn bar() {
+    match (0,1) {
+        (<|>foo!(), _) => {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macro_inside_match_arm_lhs() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! foo {() => {0}}
+           //^^^
+fn bar() {
+    match 0 {
+        <|>foo!() => {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_use_alias() {
+        check(
+            r#"
+//- /lib.rs
+use foo as bar<|>;
+
+//- /foo/lib.rs
+// empty
+//^ file
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_use_alias_foo_macro() {
+        check(
+            r#"
+//- /lib.rs
+use foo::foo as bar<|>;
+
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_methods() {
+        check(
+            r#"
+//- /lib.rs
+struct Foo;
+impl Foo {
+    fn frobnicate(&self) { }
+     //^^^^^^^^^^
+}
+
+fn bar(foo: &Foo) {
+    foo.frobnicate<|>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_fields() {
+        check(
+            r#"
+struct Foo {
+    spam: u32,
+} //^^^^
+
+fn bar(foo: &Foo) {
+    foo.spam<|>;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_record_fields() {
+        check(
+            r#"
+//- /lib.rs
+struct Foo {
+    spam: u32,
+} //^^^^
+
+fn bar() -> Foo {
+    Foo {
+        spam<|>: 0,
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_record_pat_fields() {
+        check(
+            r#"
+//- /lib.rs
+struct Foo {
+    spam: u32,
+} //^^^^
+
+fn bar(foo: Foo) -> Foo {
+    let Foo { spam<|>: _, } = foo
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_record_fields_macros() {
+        check(
+            r"
+macro_rules! m { () => { 92 };}
+struct Foo { spam: u32 }
+           //^^^^
+
+fn bar() -> Foo {
+    Foo { spam<|>: m!() }
+}
+",
+        );
+    }
+
+    #[test]
+    fn goto_for_tuple_fields() {
+        check(
+            r#"
+struct Foo(u32);
+         //^^^
+
+fn bar() {
+    let foo = Foo(0);
+    foo.<|>0;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_ufcs_inherent_methods() {
+        check(
+            r#"
+struct Foo;
+impl Foo {
+    fn frobnicate() { }
+}    //^^^^^^^^^^
+
+fn bar(foo: &Foo) {
+    Foo::frobnicate<|>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_ufcs_trait_methods_through_traits() {
+        check(
+            r#"
+trait Foo {
+    fn frobnicate();
+}    //^^^^^^^^^^
+
+fn bar() {
+    Foo::frobnicate<|>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_ufcs_trait_methods_through_self() {
+        check(
+            r#"
+struct Foo;
+trait Trait {
+    fn frobnicate();
+}    //^^^^^^^^^^
+impl Trait for Foo {}
+
+fn bar() {
+    Foo::frobnicate<|>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_definition_on_self() {
+        check(
+            r#"
+struct Foo;
+impl Foo {
+   //^^^
+    pub fn new() -> Self {
+        Self<|> {}
+    }
+}
+"#,
+        );
+        check(
+            r#"
+struct Foo;
+impl Foo {
+   //^^^
+    pub fn new() -> Self<|> {
+        Self {}
+    }
+}
+"#,
+        );
+
+        check(
+            r#"
+enum Foo { A }
+impl Foo {
+   //^^^
+    pub fn new() -> Self<|> {
+        Foo::A
+    }
+}
+"#,
+        );
+
+        check(
+            r#"
+enum Foo { A }
+impl Foo {
+   //^^^
+    pub fn thing(a: &Self<|>) {
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_definition_on_self_in_trait_impl() {
+        check(
+            r#"
+struct Foo;
+trait Make {
+    fn new() -> Self;
+}
+impl Make for Foo {
+            //^^^
+    fn new() -> Self {
+        Self<|> {}
+    }
+}
+"#,
+        );
+
+        check(
+            r#"
+struct Foo;
+trait Make {
+    fn new() -> Self;
+}
+impl Make for Foo {
+            //^^^
+    fn new() -> Self<|> {
+        Self {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_when_used_on_definition_name_itself() {
+        check(
+            r#"
+struct Foo<|> { value: u32 }
+     //^^^
+            "#,
+        );
+
+        check(
+            r#"
+struct Foo {
+    field<|>: string,
+} //^^^^^
+"#,
+        );
+
+        check(
+            r#"
+fn foo_test<|>() { }
+ //^^^^^^^^
+"#,
+        );
+
+        check(
+            r#"
+enum Foo<|> { Variant }
+   //^^^
+"#,
+        );
+
+        check(
+            r#"
+enum Foo {
+    Variant1,
+    Variant2<|>,
+  //^^^^^^^^
+    Variant3,
+}
+"#,
+        );
+
+        check(
+            r#"
+static INNER<|>: &str = "";
+     //^^^^^
+"#,
+        );
+
+        check(
+            r#"
+const INNER<|>: &str = "";
+    //^^^^^
+"#,
+        );
+
+        check(
+            r#"
+type Thing<|> = Option<()>;
+   //^^^^^
+"#,
+        );
+
+        check(
+            r#"
+trait Foo<|> { }
+    //^^^
+"#,
+        );
+
+        check(
+            r#"
+mod bar<|> { }
+  //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_from_macro() {
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => { $($tt)* }
+}
+fn foo() {}
+ //^^^
+id! {
+    fn bar() {
+        fo<|>o();
+    }
+}
+mod confuse_index { fn foo(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_through_format() {
+        check(
+            r#"
+#[macro_export]
+macro_rules! format {
+    ($($arg:tt)*) => ($crate::fmt::format($crate::__export::format_args!($($arg)*)))
+}
+#[rustc_builtin_macro]
+#[macro_export]
+macro_rules! format_args {
+    ($fmt:expr) => ({ /* compiler built-in */ });
+    ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+}
+pub mod __export {
+    pub use crate::format_args;
+    fn foo() {} // for index confusion
+}
+fn foo() -> i8 {}
+ //^^^
+fn test() {
+    format!("{}", fo<|>o())
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_for_type_param() {
+        check(
+            r#"
+struct Foo<T: Clone> { t: <|>T }
+         //^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_within_macro() {
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => ($($tt)*)
+}
+
+fn foo() {
+    let x = 1;
+      //^
+    id!({
+        let y = <|>x;
+        let z = y;
+    });
+}
+"#,
+        );
+
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => ($($tt)*)
+}
+
+fn foo() {
+    let x = 1;
+    id!({
+        let y = x;
+          //^
+        let z = <|>y;
+    });
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_in_local_fn() {
+        check(
+            r#"
+fn main() {
+    fn foo() {
+        let x = 92;
+          //^
+        <|>x;
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_in_local_macro() {
+        check(
+            r#"
+fn bar() {
+    macro_rules! foo { () => { () } }
+               //^^^
+    <|>foo!();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_field_init_shorthand() {
+        check(
+            r#"
+struct Foo { x: i32 }
+fn main() {
+    let x = 92;
+      //^
+    Foo { x<|> };
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_field() {
+        check(
+            r#"
+enum Foo {
+    Bar { x: i32 }
+}       //^
+fn baz(foo: Foo) {
+    match foo {
+        Foo::Bar { x<|> } => x
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_pattern_const() {
+        check(
+            r#"
+enum Foo { Bar }
+         //^^^
+impl Foo {
+    fn baz(self) {
+        match self { Self::Bar<|> => {} }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_pattern_record() {
+        check(
+            r#"
+enum Foo { Bar { val: i32 } }
+         //^^^
+impl Foo {
+    fn baz(self) -> i32 {
+        match self { Self::Bar<|> { val } => {} }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_expr_const() {
+        check(
+            r#"
+enum Foo { Bar }
+         //^^^
+impl Foo {
+    fn baz(self) { Self::Bar<|>; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_expr_record() {
+        check(
+            r#"
+enum Foo { Bar { val: i32 } }
+         //^^^
+impl Foo {
+    fn baz(self) { Self::Bar<|> {val: 4}; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_type_alias_generic_parameter() {
+        check(
+            r#"
+type Alias<T> = T<|>;
+         //^
+"#,
+        )
+    }
+
+    #[test]
+    fn goto_def_for_macro_container() {
+        check(
+            r#"
+//- /lib.rs
+foo::module<|>::mac!();
+
+//- /foo/lib.rs
+pub mod module {
+      //^^^^^^
+    #[macro_export]
+    macro_rules! _mac { () => { () } }
+    pub use crate::_mac as mac;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_assoc_ty_in_path() {
+        check(
+            r#"
+trait Iterator {
+    type Item;
+       //^^^^
+}
+
+fn f() -> impl Iterator<Item<|> = u8> {}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_assoc_ty_in_path_multiple() {
+        check(
+            r#"
+trait Iterator {
+    type A;
+       //^
+    type B;
+}
+
+fn f() -> impl Iterator<A<|> = u8, B = ()> {}
+"#,
+        );
+        check(
+            r#"
+trait Iterator {
+    type A;
+    type B;
+       //^
+}
+
+fn f() -> impl Iterator<A = u8, B<|> = ()> {}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_assoc_ty_ufcs() {
+        check(
+            r#"
+trait Iterator {
+    type Item;
+       //^^^^
+}
+
+fn g() -> <() as Iterator<Item<|> = ()>>::Item {}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_assoc_ty_ufcs_multiple() {
+        check(
+            r#"
+trait Iterator {
+    type A;
+       //^
+    type B;
+}
+
+fn g() -> <() as Iterator<A<|> = (), B = u8>>::B {}
+"#,
+        );
+        check(
+            r#"
+trait Iterator {
+    type A;
+    type B;
+       //^
+}
+
+fn g() -> <() as Iterator<A = (), B<|> = u8>>::A {}
+"#,
+        );
+    }
+}
diff --git a/crates/ide/src/goto_implementation.rs b/crates/ide/src/goto_implementation.rs
new file mode 100644
index 000000000..f503f4ec5
--- /dev/null
+++ b/crates/ide/src/goto_implementation.rs
@@ -0,0 +1,229 @@
+use hir::{Crate, ImplDef, Semantics};
+use ide_db::RootDatabase;
+use syntax::{algo::find_node_at_offset, ast, AstNode};
+
+use crate::{display::ToNav, FilePosition, NavigationTarget, RangeInfo};
+
+// Feature: Go to Implementation
+//
+// Navigates to the impl block of structs, enums or traits. Also implemented as a code lens.
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[Ctrl+F12]
+// |===
+pub(crate) fn goto_implementation(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let sema = Semantics::new(db);
+    let source_file = sema.parse(position.file_id);
+    let syntax = source_file.syntax().clone();
+
+    let krate = sema.to_module_def(position.file_id)?.krate();
+
+    if let Some(nominal_def) = find_node_at_offset::<ast::AdtDef>(&syntax, position.offset) {
+        return Some(RangeInfo::new(
+            nominal_def.syntax().text_range(),
+            impls_for_def(&sema, &nominal_def, krate)?,
+        ));
+    } else if let Some(trait_def) = find_node_at_offset::<ast::Trait>(&syntax, position.offset) {
+        return Some(RangeInfo::new(
+            trait_def.syntax().text_range(),
+            impls_for_trait(&sema, &trait_def, krate)?,
+        ));
+    }
+
+    None
+}
+
+fn impls_for_def(
+    sema: &Semantics<RootDatabase>,
+    node: &ast::AdtDef,
+    krate: Crate,
+) -> Option<Vec<NavigationTarget>> {
+    let ty = match node {
+        ast::AdtDef::Struct(def) => sema.to_def(def)?.ty(sema.db),
+        ast::AdtDef::Enum(def) => sema.to_def(def)?.ty(sema.db),
+        ast::AdtDef::Union(def) => sema.to_def(def)?.ty(sema.db),
+    };
+
+    let impls = ImplDef::all_in_crate(sema.db, krate);
+
+    Some(
+        impls
+            .into_iter()
+            .filter(|impl_def| ty.is_equal_for_find_impls(&impl_def.target_ty(sema.db)))
+            .map(|imp| imp.to_nav(sema.db))
+            .collect(),
+    )
+}
+
+fn impls_for_trait(
+    sema: &Semantics<RootDatabase>,
+    node: &ast::Trait,
+    krate: Crate,
+) -> Option<Vec<NavigationTarget>> {
+    let tr = sema.to_def(node)?;
+
+    let impls = ImplDef::for_trait(sema.db, krate, tr);
+
+    Some(impls.into_iter().map(|imp| imp.to_nav(sema.db)).collect())
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::FileRange;
+
+    use crate::mock_analysis::MockAnalysis;
+
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let annotations = mock.annotations();
+        let analysis = mock.analysis();
+
+        let navs = analysis.goto_implementation(position).unwrap().unwrap().info;
+
+        let key = |frange: &FileRange| (frange.file_id, frange.range.start());
+
+        let mut expected = annotations
+            .into_iter()
+            .map(|(range, data)| {
+                assert!(data.is_empty());
+                range
+            })
+            .collect::<Vec<_>>();
+        expected.sort_by_key(key);
+
+        let mut actual = navs
+            .into_iter()
+            .map(|nav| FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() })
+            .collect::<Vec<_>>();
+        actual.sort_by_key(key);
+
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn goto_implementation_works() {
+        check(
+            r#"
+struct Foo<|>;
+impl Foo {}
+   //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_blocks() {
+        check(
+            r#"
+struct Foo<|>;
+impl Foo {}
+   //^^^
+impl Foo {}
+   //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_mods() {
+        check(
+            r#"
+struct Foo<|>;
+mod a {
+    impl super::Foo {}
+       //^^^^^^^^^^
+}
+mod b {
+    impl super::Foo {}
+       //^^^^^^^^^^
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_files() {
+        check(
+            r#"
+//- /lib.rs
+struct Foo<|>;
+mod a;
+mod b;
+//- /a.rs
+impl crate::Foo {}
+   //^^^^^^^^^^
+//- /b.rs
+impl crate::Foo {}
+   //^^^^^^^^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_for_trait() {
+        check(
+            r#"
+trait T<|> {}
+struct Foo;
+impl T for Foo {}
+         //^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_for_trait_multiple_files() {
+        check(
+            r#"
+//- /lib.rs
+trait T<|> {};
+struct Foo;
+mod a;
+mod b;
+//- /a.rs
+impl crate::T for crate::Foo {}
+                //^^^^^^^^^^
+//- /b.rs
+impl crate::T for crate::Foo {}
+                //^^^^^^^^^^
+            "#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_all_impls() {
+        check(
+            r#"
+//- /lib.rs
+trait T {}
+struct Foo<|>;
+impl Foo {}
+   //^^^
+impl T for Foo {}
+         //^^^
+impl T for &Foo {}
+         //^^^^
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_implementation_to_builtin_derive() {
+        check(
+            r#"
+  #[derive(Copy)]
+//^^^^^^^^^^^^^^^
+struct Foo<|>;
+
+mod marker {
+    trait Copy {}
+}
+"#,
+        );
+    }
+}
diff --git a/crates/ide/src/goto_type_definition.rs b/crates/ide/src/goto_type_definition.rs
new file mode 100644
index 000000000..4a151b150
--- /dev/null
+++ b/crates/ide/src/goto_type_definition.rs
@@ -0,0 +1,151 @@
+use ide_db::RootDatabase;
+use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
+
+use crate::{display::ToNav, FilePosition, NavigationTarget, RangeInfo};
+
+// Feature: Go to Type Definition
+//
+// Navigates to the type of an identifier.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Go to Type Definition*
+// |===
+pub(crate) fn goto_type_definition(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let sema = hir::Semantics::new(db);
+
+    let file: ast::SourceFile = sema.parse(position.file_id);
+    let token: SyntaxToken = pick_best(file.syntax().token_at_offset(position.offset))?;
+    let token: SyntaxToken = sema.descend_into_macros(token);
+
+    let (ty, node) = sema.ancestors_with_macros(token.parent()).find_map(|node| {
+        let ty = match_ast! {
+            match node {
+                ast::Expr(it) => sema.type_of_expr(&it)?,
+                ast::Pat(it) => sema.type_of_pat(&it)?,
+                ast::SelfParam(it) => sema.type_of_self(&it)?,
+                _ => return None,
+            }
+        };
+
+        Some((ty, node))
+    })?;
+
+    let adt_def = ty.autoderef(db).filter_map(|ty| ty.as_adt()).last()?;
+
+    let nav = adt_def.to_nav(db);
+    Some(RangeInfo::new(node.text_range(), vec![nav]))
+}
+
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER | T![self] => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::FileRange;
+
+    use crate::mock_analysis::MockAnalysis;
+
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let (expected, data) = mock.annotation();
+        assert!(data.is_empty());
+        let analysis = mock.analysis();
+
+        let mut navs = analysis.goto_type_definition(position).unwrap().unwrap().info;
+        assert_eq!(navs.len(), 1);
+        let nav = navs.pop().unwrap();
+        assert_eq!(expected, FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() });
+    }
+
+    #[test]
+    fn goto_type_definition_works_simple() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo() {
+    let f: Foo; f<|>
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_works_simple_ref() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo() {
+    let f: &Foo; f<|>
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_works_through_macro() {
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+struct Foo {}
+     //^^^
+id! {
+    fn bar() { let f<|> = Foo {}; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_for_param() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo(<|>f: Foo) {}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_for_tuple_field() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+struct Bar(Foo);
+fn foo() {
+    let bar = Bar(Foo);
+    bar.<|>0;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_self_param() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+impl Foo {
+    fn f(&self<|>) {}
+}
+"#,
+        )
+    }
+}
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
new file mode 100644
index 000000000..331aa4db0
--- /dev/null
+++ b/crates/ide/src/hover.rs
@@ -0,0 +1,2461 @@
+use base_db::SourceDatabase;
+use hir::{
+    Adt, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource, HirDisplay,
+    Module, ModuleDef, ModuleSource, Semantics,
+};
+use ide_db::{
+    defs::{classify_name, classify_name_ref, Definition},
+    RootDatabase,
+};
+use itertools::Itertools;
+use stdx::format_to;
+use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
+use test_utils::mark;
+
+use crate::{
+    display::{macro_label, ShortLabel, ToNav, TryToNav},
+    markup::Markup,
+    runnables::runnable,
+    FileId, FilePosition, NavigationTarget, RangeInfo, Runnable,
+};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct HoverConfig {
+    pub implementations: bool,
+    pub run: bool,
+    pub debug: bool,
+    pub goto_type_def: bool,
+}
+
+impl Default for HoverConfig {
+    fn default() -> Self {
+        Self { implementations: true, run: true, debug: true, goto_type_def: true }
+    }
+}
+
+impl HoverConfig {
+    pub const NO_ACTIONS: Self =
+        Self { implementations: false, run: false, debug: false, goto_type_def: false };
+
+    pub fn any(&self) -> bool {
+        self.implementations || self.runnable() || self.goto_type_def
+    }
+
+    pub fn none(&self) -> bool {
+        !self.any()
+    }
+
+    pub fn runnable(&self) -> bool {
+        self.run || self.debug
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum HoverAction {
+    Runnable(Runnable),
+    Implementaion(FilePosition),
+    GoToType(Vec<HoverGotoTypeData>),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct HoverGotoTypeData {
+    pub mod_path: String,
+    pub nav: NavigationTarget,
+}
+
+/// Contains the results when hovering over an item
+#[derive(Debug, Default)]
+pub struct HoverResult {
+    pub markup: Markup,
+    pub actions: Vec<HoverAction>,
+}
+
+// Feature: Hover
+//
+// Shows additional information, like type of an expression or documentation for definition when "focusing" code.
+// Focusing is usually hovering with a mouse, but can also be triggered with a shortcut.
+pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo<HoverResult>> {
+    let sema = Semantics::new(db);
+    let file = sema.parse(position.file_id).syntax().clone();
+    let token = pick_best(file.token_at_offset(position.offset))?;
+    let token = sema.descend_into_macros(token);
+
+    let mut res = HoverResult::default();
+
+    let node = token.parent();
+    let definition = match_ast! {
+        match node {
+            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition(sema.db)),
+            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition(sema.db)),
+            _ => None,
+        }
+    };
+    if let Some(definition) = definition {
+        if let Some(markup) = hover_for_definition(db, definition) {
+            res.markup = markup;
+            if let Some(action) = show_implementations_action(db, definition) {
+                res.actions.push(action);
+            }
+
+            if let Some(action) = runnable_action(&sema, definition, position.file_id) {
+                res.actions.push(action);
+            }
+
+            if let Some(action) = goto_type_action(db, definition) {
+                res.actions.push(action);
+            }
+
+            let range = sema.original_range(&node).range;
+            return Some(RangeInfo::new(range, res));
+        }
+    }
+
+    let node = token
+        .ancestors()
+        .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())?;
+
+    let ty = match_ast! {
+        match node {
+            ast::Expr(it) => sema.type_of_expr(&it)?,
+            ast::Pat(it) => sema.type_of_pat(&it)?,
+            // If this node is a MACRO_CALL, it means that `descend_into_macros` failed to resolve.
+            // (e.g expanding a builtin macro). So we give up here.
+            ast::MacroCall(_it) => return None,
+            _ => return None,
+        }
+    };
+
+    res.markup = Markup::fenced_block(&ty.display(db));
+    let range = sema.original_range(&node).range;
+    Some(RangeInfo::new(range, res))
+}
+
+fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    fn to_action(nav_target: NavigationTarget) -> HoverAction {
+        HoverAction::Implementaion(FilePosition {
+            file_id: nav_target.file_id,
+            offset: nav_target.focus_or_full_range().start(),
+        })
+    }
+
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Adt(Adt::Struct(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Union(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Enum(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Trait(it) => Some(to_action(it.to_nav(db))),
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+fn runnable_action(
+    sema: &Semantics<RootDatabase>,
+    def: Definition,
+    file_id: FileId,
+) -> Option<HoverAction> {
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Module(it) => match it.definition_source(sema.db).value {
+                ModuleSource::Module(it) => runnable(&sema, it.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it)),
+                _ => None,
+            },
+            ModuleDef::Function(it) => {
+                let src = it.source(sema.db);
+                if src.file_id != file_id.into() {
+                    mark::hit!(hover_macro_generated_struct_fn_doc_comment);
+                    mark::hit!(hover_macro_generated_struct_fn_doc_attr);
+
+                    return None;
+                }
+
+                runnable(&sema, src.value.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it))
+            }
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    match def {
+        Definition::Local(it) => {
+            let mut targets: Vec<ModuleDef> = Vec::new();
+            let mut push_new_def = |item: ModuleDef| {
+                if !targets.contains(&item) {
+                    targets.push(item);
+                }
+            };
+
+            it.ty(db).walk(db, |t| {
+                if let Some(adt) = t.as_adt() {
+                    push_new_def(adt.into());
+                } else if let Some(trait_) = t.as_dyn_trait() {
+                    push_new_def(trait_.into());
+                } else if let Some(traits) = t.as_impl_traits(db) {
+                    traits.into_iter().for_each(|it| push_new_def(it.into()));
+                } else if let Some(trait_) = t.as_associated_type_parent_trait(db) {
+                    push_new_def(trait_.into());
+                }
+            });
+
+            let targets = targets
+                .into_iter()
+                .filter_map(|it| {
+                    Some(HoverGotoTypeData {
+                        mod_path: render_path(
+                            db,
+                            it.module(db)?,
+                            it.name(db).map(|name| name.to_string()),
+                        ),
+                        nav: it.try_to_nav(db)?,
+                    })
+                })
+                .collect();
+
+            Some(HoverAction::GoToType(targets))
+        }
+        _ => None,
+    }
+}
+
+fn hover_markup(
+    docs: Option<String>,
+    desc: Option<String>,
+    mod_path: Option<String>,
+) -> Option<Markup> {
+    match desc {
+        Some(desc) => {
+            let mut buf = String::new();
+
+            if let Some(mod_path) = mod_path {
+                if !mod_path.is_empty() {
+                    format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
+                }
+            }
+            format_to!(buf, "```rust\n{}\n```", desc);
+
+            if let Some(doc) = docs {
+                format_to!(buf, "\n___\n\n{}", doc);
+            }
+            Some(buf.into())
+        }
+        None => docs.map(Markup::from),
+    }
+}
+
+fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String> {
+    match def {
+        Definition::Field(f) => Some(f.parent_def(db).name(db)),
+        Definition::Local(l) => l.parent(db).name(db),
+        Definition::ModuleDef(md) => match md {
+            ModuleDef::Function(f) => match f.as_assoc_item(db)?.container(db) {
+                AssocItemContainer::Trait(t) => Some(t.name(db)),
+                AssocItemContainer::ImplDef(i) => i.target_ty(db).as_adt().map(|adt| adt.name(db)),
+            },
+            ModuleDef::EnumVariant(e) => Some(e.parent_enum(db).name(db)),
+            _ => None,
+        },
+        Definition::SelfType(i) => i.target_ty(db).as_adt().map(|adt| adt.name(db)),
+        _ => None,
+    }
+    .map(|name| name.to_string())
+}
+
+fn render_path(db: &RootDatabase, module: Module, item_name: Option<String>) -> String {
+    let crate_name =
+        db.crate_graph()[module.krate().into()].display_name.as_ref().map(ToString::to_string);
+    let module_path = module
+        .path_to_root(db)
+        .into_iter()
+        .rev()
+        .flat_map(|it| it.name(db).map(|name| name.to_string()));
+    crate_name.into_iter().chain(module_path).chain(item_name).join("::")
+}
+
+fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
+    def.module(db).map(|module| render_path(db, module, definition_owner_name(db, def)))
+}
+
+fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
+    let mod_path = definition_mod_path(db, &def);
+    return match def {
+        Definition::Macro(it) => {
+            let src = it.source(db);
+            let docs = Documentation::from_ast(&src.value).map(Into::into);
+            hover_markup(docs, Some(macro_label(&src.value)), mod_path)
+        }
+        Definition::Field(it) => {
+            let src = it.source(db);
+            match src.value {
+                FieldSource::Named(it) => {
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
+                }
+                _ => None,
+            }
+        }
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Module(it) => match it.definition_source(db).value {
+                ModuleSource::Module(it) => {
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
+                }
+                ModuleSource::SourceFile(it) => {
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
+                }
+            },
+            ModuleDef::Function(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Adt(Adt::Struct(it)) => from_def_source(db, it, mod_path),
+            ModuleDef::Adt(Adt::Union(it)) => from_def_source(db, it, mod_path),
+            ModuleDef::Adt(Adt::Enum(it)) => from_def_source(db, it, mod_path),
+            ModuleDef::EnumVariant(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Const(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Static(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Trait(it) => from_def_source(db, it, mod_path),
+            ModuleDef::TypeAlias(it) => from_def_source(db, it, mod_path),
+            ModuleDef::BuiltinType(it) => return Some(it.to_string().into()),
+        },
+        Definition::Local(it) => return Some(Markup::fenced_block(&it.ty(db).display(db))),
+        Definition::TypeParam(_) | Definition::SelfType(_) => {
+            // FIXME: Hover for generic param
+            None
+        }
+    };
+
+    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
+    where
+        D: HasSource<Ast = A>,
+        A: ast::DocCommentsOwner + ast::NameOwner + ShortLabel + ast::AttrsOwner,
+    {
+        let src = def.source(db);
+        let docs = Documentation::from_ast(&src.value).map(Into::into);
+        hover_markup(docs, src.value.short_label(), mod_path)
+    }
+}
+
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER => 3,
+            T!['('] | T![')'] => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::FileLoader;
+    use expect::{expect, Expect};
+
+    use crate::mock_analysis::analysis_and_position;
+
+    use super::*;
+
+    fn check_hover_no_result(ra_fixture: &str) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        assert!(analysis.hover(position).unwrap().is_none());
+    }
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let hover = analysis.hover(position).unwrap().unwrap();
+
+        let content = analysis.db.file_text(position.file_id);
+        let hovered_element = &content[hover.range];
+
+        let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+        expect.assert_eq(&actual)
+    }
+
+    fn check_actions(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let hover = analysis.hover(position).unwrap().unwrap();
+        expect.assert_debug_eq(&hover.info.actions)
+    }
+
+    #[test]
+    fn hover_shows_type_of_an_expression() {
+        check(
+            r#"
+pub fn foo() -> u32 { 1 }
+
+fn main() {
+    let foo_test = foo()<|>;
+}
+"#,
+            expect![[r#"
+                *foo()*
+                ```rust
+                u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_long_type_of_an_expression() {
+        check(
+            r#"
+struct Scan<A, B, C> { a: A, b: B, c: C }
+struct Iter<I> { inner: I }
+enum Option<T> { Some(T), None }
+
+struct OtherStruct<T> { i: T }
+
+fn scan<A, B, C>(a: A, b: B, c: C) -> Iter<Scan<OtherStruct<A>, B, C>> {
+    Iter { inner: Scan { a, b, c } }
+}
+
+fn main() {
+    let num: i32 = 55;
+    let closure = |memo: &mut u32, value: &u32, _another: &mut u32| -> Option<u32> {
+        Option::Some(*memo + value)
+    };
+    let number = 5u32;
+    let mut iter<|> = scan(OtherStruct { i: num }, closure, number);
+}
+"#,
+            expect![[r#"
+                *iter*
+                ```rust
+                Iter<Scan<OtherStruct<OtherStruct<i32>>, |&mut u32, &u32, &mut u32| -> Option<u32>, u32>>
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_fn_signature() {
+        // Single file with result
+        check(
+            r#"
+pub fn foo() -> u32 { 1 }
+
+fn main() { let foo_test = fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo() -> u32
+                ```
+            "#]],
+        );
+
+        // Multiple candidates but results are ambiguous.
+        check(
+            r#"
+//- /a.rs
+pub fn foo() -> u32 { 1 }
+
+//- /b.rs
+pub fn foo() -> &str { "" }
+
+//- /c.rs
+pub fn foo(a: u32, b: u32) {}
+
+//- /main.rs
+mod a;
+mod b;
+mod c;
+
+fn main() { let foo_test = fo<|>o(); }
+        "#,
+            expect![[r#"
+                *foo*
+                ```rust
+                {unknown}
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_fn_signature_with_type_params() {
+        check(
+            r#"
+pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str { }
+
+fn main() { let foo_test = fo<|>o(); }
+        "#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_fn_signature_on_fn_name() {
+        check(
+            r#"
+pub fn foo<|>(a: u32, b: u32) -> u32 {}
+
+fn main() { }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo(a: u32, b: u32) -> u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_fn_doc() {
+        check(
+            r#"
+/// # Example
+/// ```
+/// # use std::path::Path;
+/// #
+/// foo(Path::new("hello, world!"))
+/// ```
+pub fn foo<|>(_: &Path) {}
+
+fn main() { }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo(_: &Path)
+                ```
+                ___
+
+                # Example
+                ```
+                # use std::path::Path;
+                #
+                foo(Path::new("hello, world!"))
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_shows_struct_field_info() {
+        // Hovering over the field when instantiating
+        check(
+            r#"
+struct Foo { field_a: u32 }
+
+fn main() {
+    let foo = Foo { field_a<|>: 0, };
+}
+"#,
+            expect![[r#"
+                *field_a*
+                ```rust
+                Foo
+                ```
+
+                ```rust
+                field_a: u32
+                ```
+            "#]],
+        );
+
+        // Hovering over the field in the definition
+        check(
+            r#"
+struct Foo { field_a<|>: u32 }
+
+fn main() {
+    let foo = Foo { field_a: 0 };
+}
+"#,
+            expect![[r#"
+                *field_a*
+                ```rust
+                Foo
+                ```
+
+                ```rust
+                field_a: u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_const_static() {
+        check(
+            r#"const foo<|>: u32 = 123;"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                const foo: u32 = 123
+                ```
+            "#]],
+        );
+        check(
+            r#"static foo<|>: u32 = 456;"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                static foo: u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_default_generic_types() {
+        check(
+            r#"
+struct Test<K, T = u8> { k: K, t: T }
+
+fn main() {
+    let zz<|> = Test { t: 23u8, k: 33 };
+}"#,
+            expect![[r#"
+                *zz*
+                ```rust
+                Test<i32, u8>
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_some() {
+        check(
+            r#"
+enum Option<T> { Some(T) }
+use Option::Some;
+
+fn main() { So<|>me(12); }
+"#,
+            expect![[r#"
+                *Some*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                Some
+                ```
+            "#]],
+        );
+
+        check(
+            r#"
+enum Option<T> { Some(T) }
+use Option::Some;
+
+fn main() { let b<|>ar = Some(12); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                Option<i32>
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_enum_variant() {
+        check(
+            r#"
+enum Option<T> {
+    /// The None variant
+    Non<|>e
+}
+"#,
+            expect![[r#"
+                *None*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                None
+                ```
+                ___
+
+                The None variant
+            "#]],
+        );
+
+        check(
+            r#"
+enum Option<T> {
+    /// The Some variant
+    Some(T)
+}
+fn main() {
+    let s = Option::Som<|>e(12);
+}
+"#,
+            expect![[r#"
+                *Some*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                Some
+                ```
+                ___
+
+                The Some variant
+            "#]],
+        );
+    }
+
+    #[test]
+    fn hover_for_local_variable() {
+        check(
+            r#"fn func(foo: i32) { fo<|>o; }"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn hover_for_local_variable_pat() {
+        check(
+            r#"fn func(fo<|>o: i32) {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn hover_local_var_edge() {
+        check(
+            r#"fn func(foo: i32) { if true { <|>foo; }; }"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn hover_for_param_edge() {
+        check(
+            r#"fn func(<|>foo: i32) {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_infer_associated_method_result() {
+        check(
+            r#"
+struct Thing { x: u32 }
+
+impl Thing {
+    fn new() -> Thing { Thing { x: 0 } }
+}
+
+fn main() { let foo_<|>test = Thing::new(); }
+            "#,
+            expect![[r#"
+                *foo_test*
+                ```rust
+                Thing
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_infer_associated_method_exact() {
+        check(
+            r#"
+mod wrapper {
+    struct Thing { x: u32 }
+
+    impl Thing {
+        fn new() -> Thing { Thing { x: 0 } }
+    }
+}
+
+fn main() { let foo_test = wrapper::Thing::new<|>(); }
+"#,
+            expect![[r#"
+                *new*
+                ```rust
+                wrapper::Thing
+                ```
+
+                ```rust
+                fn new() -> Thing
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_infer_associated_const_in_pattern() {
+        check(
+            r#"
+struct X;
+impl X {
+    const C: u32 = 1;
+}
+
+fn main() {
+    match 1 {
+        X::C<|> => {},
+        2 => {},
+        _ => {}
+    };
+}
+"#,
+            expect![[r#"
+                *C*
+                ```rust
+                const C: u32 = 1
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_self() {
+        check(
+            r#"
+struct Thing { x: u32 }
+impl Thing {
+    fn new() -> Self { Self<|> { x: 0 } }
+}
+"#,
+            expect![[r#"
+                *Self { x: 0 }*
+                ```rust
+                Thing
+                ```
+            "#]],
+        )
+    } /* FIXME: revive these tests
+              let (analysis, position) = analysis_and_position(
+                  "
+                  struct Thing { x: u32 }
+                  impl Thing {
+                      fn new() -> Self<|> {
+                          Self { x: 0 }
+                      }
+                  }
+                  ",
+              );
+
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("Thing"));
+
+              let (analysis, position) = analysis_and_position(
+                  "
+                  enum Thing { A }
+                  impl Thing {
+                      pub fn new() -> Self<|> {
+                          Thing::A
+                      }
+                  }
+                  ",
+              );
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("enum Thing"));
+
+              let (analysis, position) = analysis_and_position(
+                  "
+                  enum Thing { A }
+                  impl Thing {
+                      pub fn thing(a: Self<|>) {
+                      }
+                  }
+                  ",
+              );
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("enum Thing"));
+      */
+
+    #[test]
+    fn test_hover_shadowing_pat() {
+        check(
+            r#"
+fn x() {}
+
+fn y() {
+    let x = 0i32;
+    x<|>;
+}
+"#,
+            expect![[r#"
+                *x*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_macro_invocation() {
+        check(
+            r#"
+macro_rules! foo { () => {} }
+
+fn f() { fo<|>o!(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                macro_rules! foo
+                ```
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_tuple_field() {
+        check(
+            r#"struct TS(String, i32<|>);"#,
+            expect![[r#"
+                *i32*
+                i32
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_hover_through_macro() {
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() {}
+id! {
+    fn bar() { fo<|>o(); }
+}
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                fn foo()
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_expr_in_macro() {
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo(bar:u32) { let a = id!(ba<|>r); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_expr_in_macro_recursive() {
+        check(
+            r#"
+macro_rules! id_deep { ($($tt:tt)*) => { $($tt)* } }
+macro_rules! id { ($($tt:tt)*) => { id_deep!($($tt)*) } }
+fn foo(bar:u32) { let a = id!(ba<|>r); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_func_in_macro_recursive() {
+        check(
+            r#"
+macro_rules! id_deep { ($($tt:tt)*) => { $($tt)* } }
+macro_rules! id { ($($tt:tt)*) => { id_deep!($($tt)*) } }
+fn bar() -> u32 { 0 }
+fn foo() { let a = id!([0u32, bar(<|>)] ); }
+"#,
+            expect![[r#"
+                *bar()*
+                ```rust
+                u32
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_literal_string_in_macro() {
+        check(
+            r#"
+macro_rules! arr { ($($tt:tt)*) => { [$($tt)*)] } }
+fn foo() {
+    let mastered_for_itunes = "";
+    let _ = arr!("Tr<|>acks", &mastered_for_itunes);
+}
+"#,
+            expect![[r#"
+                *"Tracks"*
+                ```rust
+                &str
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_assert_macro() {
+        check(
+            r#"
+#[rustc_builtin_macro]
+macro_rules! assert {}
+
+fn bar() -> bool { true }
+fn foo() {
+    assert!(ba<|>r());
+}
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                fn bar() -> bool
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_through_literal_string_in_builtin_macro() {
+        check_hover_no_result(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! format {}
+
+            fn foo() {
+                format!("hel<|>lo {}", 0);
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn test_hover_non_ascii_space_doc() {
+        check(
+            "
+///　<- `\u{3000}` here
+fn foo() { }
+
+fn bar() { fo<|>o(); }
+",
+            expect![[r#"
+                *foo*
+                ```rust
+                fn foo()
+                ```
+                ___
+
+                <- `　` here
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_function_show_qualifiers() {
+        check(
+            r#"async fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                async fn foo()
+                ```
+            "#]],
+        );
+        check(
+            r#"pub const unsafe fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub const unsafe fn foo()
+                ```
+            "#]],
+        );
+        check(
+            r#"pub(crate) async unsafe extern "C" fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub(crate) async unsafe extern "C" fn foo()
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_trait_show_qualifiers() {
+        check_actions(
+            r"unsafe trait foo<|>() {}",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 13,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_extern_crate() {
+        check(
+            r#"
+//- /main.rs
+extern crate st<|>d;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *std*
+            Standard library for this test
+
+            Printed?
+            abc123
+            "#]],
+        );
+        check(
+            r#"
+//- /main.rs
+extern crate std as ab<|>c;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *abc*
+            Standard library for this test
+
+            Printed?
+            abc123
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_mod_with_same_name_as_function() {
+        check(
+            r#"
+use self::m<|>y::Bar;
+mod my { pub struct Bar; }
+
+fn my() {}
+"#,
+            expect![[r#"
+                *my*
+                ```rust
+                mod my
+                ```
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_comment() {
+        check(
+            r#"
+/// bar docs
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr() {
+        check(
+            r#"
+#[doc = "bar docs"]
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr_multiple_and_mixed() {
+        check(
+            r#"
+/// bar docs 0
+#[doc = "bar docs 1"]
+#[doc = "bar docs 2"]
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs 0
+
+                bar docs 1
+
+                bar docs 2
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_comment() {
+        mark::check!(hover_macro_generated_struct_fn_doc_comment);
+
+        check(
+            r#"
+macro_rules! bar {
+    () => {
+        struct Bar;
+        impl Bar {
+            /// Do the foo
+            fn foo(&self) {}
+        }
+    }
+}
+
+bar!();
+
+fn foo() { let bar = Bar; bar.fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                Bar
+                ```
+
+                ```rust
+                fn foo(&self)
+                ```
+                ___
+
+                 Do the foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_attr() {
+        mark::check!(hover_macro_generated_struct_fn_doc_attr);
+
+        check(
+            r#"
+macro_rules! bar {
+    () => {
+        struct Bar;
+        impl Bar {
+            #[doc = "Do the foo"]
+            fn foo(&self) {}
+        }
+    }
+}
+
+bar!();
+
+fn foo() { let bar = Bar; bar.fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                Bar
+                ```
+
+                ```rust
+                fn foo(&self)
+                ```
+                ___
+
+                Do the foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_trait_has_impl_action() {
+        check_actions(
+            r#"trait foo<|>() {}"#,
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 6,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_has_impl_action() {
+        check_actions(
+            r"struct foo<|>() {}",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 7,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_union_has_impl_action() {
+        check_actions(
+            r#"union foo<|>() {}"#,
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 6,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_enum_has_impl_action() {
+        check_actions(
+            r"enum foo<|>() { A, B }",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 5,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_test_has_action() {
+        check_actions(
+            r#"
+#[test]
+fn foo_<|>test() {}
+"#,
+            expect![[r#"
+                [
+                    Runnable(
+                        Runnable {
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..24,
+                                focus_range: Some(
+                                    11..19,
+                                ),
+                                name: "foo_test",
+                                kind: FN,
+                                container_name: None,
+                                description: None,
+                                docs: None,
+                            },
+                            kind: Test {
+                                test_id: Path(
+                                    "foo_test",
+                                ),
+                                attr: TestAttr {
+                                    ignore: false,
+                                },
+                            },
+                            cfg_exprs: [],
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_test_mod_has_action() {
+        check_actions(
+            r#"
+mod tests<|> {
+    #[test]
+    fn foo_test() {}
+}
+"#,
+            expect![[r#"
+                [
+                    Runnable(
+                        Runnable {
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..46,
+                                focus_range: Some(
+                                    4..9,
+                                ),
+                                name: "tests",
+                                kind: MODULE,
+                                container_name: None,
+                                description: None,
+                                docs: None,
+                            },
+                            kind: TestMod {
+                                path: "tests",
+                            },
+                            cfg_exprs: [],
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_has_goto_type_action() {
+        check_actions(
+            r#"
+struct S{ f1: u32 }
+
+fn main() { let s<|>t = S{ f1:0 }; }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..19,
+                                    focus_range: Some(
+                                        7..8,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_goto_type_actions() {
+        check_actions(
+            r#"
+struct Arg(u32);
+struct S<T>{ f1: T }
+
+fn main() { let s<|>t = S{ f1:Arg(0) }; }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 17..37,
+                                    focus_range: Some(
+                                        24..25,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Arg",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..16,
+                                    focus_range: Some(
+                                        7..10,
+                                    ),
+                                    name: "Arg",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct Arg",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_flattened_goto_type_actions() {
+        check_actions(
+            r#"
+struct Arg(u32);
+struct S<T>{ f1: T }
+
+fn main() { let s<|>t = S{ f1: S{ f1: Arg(0) } }; }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 17..37,
+                                    focus_range: Some(
+                                        24..25,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Arg",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..16,
+                                    focus_range: Some(
+                                        7..10,
+                                    ),
+                                    name: "Arg",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct Arg",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_tuple_has_goto_type_actions() {
+        check_actions(
+            r#"
+struct A(u32);
+struct B(u32);
+mod M {
+    pub struct C(u32);
+}
+
+fn main() { let s<|>t = (A(1), B(2), M::C(3) ); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "A",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..14,
+                                    focus_range: Some(
+                                        7..8,
+                                    ),
+                                    name: "A",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct A",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 15..29,
+                                    focus_range: Some(
+                                        22..23,
+                                    ),
+                                    name: "B",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "M::C",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 42..60,
+                                    focus_range: Some(
+                                        53..54,
+                                    ),
+                                    name: "C",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "pub struct C",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_return_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo() -> impl Foo {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_return_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S;
+fn foo() -> impl Foo<S> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..25,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_return_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+trait Bar {}
+fn foo() -> impl Foo + Bar {}
+
+fn main() { let s<|>t = foo(); }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 13..25,
+                                    focus_range: Some(
+                                        19..22,
+                                    ),
+                                    name: "Bar",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_return_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+trait Bar<T> {}
+struct S1 {}
+struct S2 {}
+
+fn foo() -> impl Foo<S1> + Bar<S2> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..31,
+                                    focus_range: Some(
+                                        22..25,
+                                    ),
+                                    name: "Bar",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S1",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 32..44,
+                                    focus_range: Some(
+                                        39..41,
+                                    ),
+                                    name: "S1",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S1",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S2",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 45..57,
+                                    focus_range: Some(
+                                        52..54,
+                                    ),
+                                    name: "S2",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S2",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo(ar<|>g: &impl Foo) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+trait Bar<T> {}
+struct S{}
+
+fn foo(ar<|>g: &impl Foo + Bar<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 13..28,
+                                    focus_range: Some(
+                                        19..22,
+                                    ),
+                                    name: "Bar",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 29..39,
+                                    focus_range: Some(
+                                        36..37,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_generic_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S {}
+fn foo(ar<|>g: &impl Foo<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..27,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_dyn_return_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+struct S;
+impl Foo for S {}
+
+struct B<T>{}
+fn foo() -> B<dyn Foo> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 42..55,
+                                    focus_range: Some(
+                                        49..50,
+                                    ),
+                                    name: "B",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_dyn_arg_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo(ar<|>g: &dyn Foo) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_dyn_arg_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S {}
+fn foo(ar<|>g: &dyn Foo<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..27,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_goto_type_action_links_order() {
+        check_actions(
+            r#"
+trait ImplTrait<T> {}
+trait DynTrait<T> {}
+struct B<T> {}
+struct S {}
+
+fn foo(a<|>rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "ImplTrait",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..21,
+                                    focus_range: Some(
+                                        6..15,
+                                    ),
+                                    name: "ImplTrait",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait ImplTrait",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 43..57,
+                                    focus_range: Some(
+                                        50..51,
+                                    ),
+                                    name: "B",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "DynTrait",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 22..42,
+                                    focus_range: Some(
+                                        28..36,
+                                    ),
+                                    name: "DynTrait",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait DynTrait",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 58..69,
+                                    focus_range: Some(
+                                        65..66,
+                                    ),
+                                    name: "S",
+                                    kind: STRUCT,
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_associated_type_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {
+    type Item;
+    fn get(self) -> Self::Item {}
+}
+
+struct Bar{}
+struct S{}
+
+impl Foo for S { type Item = Bar; }
+
+fn test() -> impl Foo { S {} }
+
+fn main() { let s<|>t = test().get(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..62,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    name: "Foo",
+                                    kind: TRAIT,
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
new file mode 100644
index 000000000..002adf915
--- /dev/null
+++ b/crates/ide/src/inlay_hints.rs
@@ -0,0 +1,927 @@
+use hir::{Adt, Callable, HirDisplay, Semantics, Type};
+use ide_db::RootDatabase;
+use stdx::to_lower_snake_case;
+use syntax::{
+    ast::{self, ArgListOwner, AstNode},
+    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T,
+};
+
+use crate::FileId;
+use ast::NameOwner;
+use either::Either;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct InlayHintsConfig {
+    pub type_hints: bool,
+    pub parameter_hints: bool,
+    pub chaining_hints: bool,
+    pub max_length: Option<usize>,
+}
+
+impl Default for InlayHintsConfig {
+    fn default() -> Self {
+        Self { type_hints: true, parameter_hints: true, chaining_hints: true, max_length: None }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum InlayKind {
+    TypeHint,
+    ParameterHint,
+    ChainingHint,
+}
+
+#[derive(Debug)]
+pub struct InlayHint {
+    pub range: TextRange,
+    pub kind: InlayKind,
+    pub label: SmolStr,
+}
+
+// Feature: Inlay Hints
+//
+// rust-analyzer shows additional information inline with the source code.
+// Editors usually render this using read-only virtual text snippets interspersed with code.
+//
+// rust-analyzer shows hits for
+//
+// * types of local variables
+// * names of function arguments
+// * types of chained expressions
+//
+// **Note:** VS Code does not have native support for inlay hints https://github.com/microsoft/vscode/issues/16221[yet] and the hints are implemented using decorations.
+// This approach has limitations, the caret movement and bracket highlighting near the edges of the hint may be weird:
+// https://github.com/rust-analyzer/rust-analyzer/issues/1623[1], https://github.com/rust-analyzer/rust-analyzer/issues/3453[2].
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Toggle inlay hints*
+// |===
+pub(crate) fn inlay_hints(
+    db: &RootDatabase,
+    file_id: FileId,
+    config: &InlayHintsConfig,
+) -> Vec<InlayHint> {
+    let _p = profile::span("inlay_hints");
+    let sema = Semantics::new(db);
+    let file = sema.parse(file_id);
+
+    let mut res = Vec::new();
+    for node in file.syntax().descendants() {
+        if let Some(expr) = ast::Expr::cast(node.clone()) {
+            get_chaining_hints(&mut res, &sema, config, expr);
+        }
+
+        match_ast! {
+            match node {
+                ast::CallExpr(it) => { get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it)); },
+                ast::MethodCallExpr(it) => { get_param_name_hints(&mut res, &sema, config, ast::Expr::from(it)); },
+                ast::IdentPat(it) => { get_bind_pat_hints(&mut res, &sema, config, it); },
+                _ => (),
+            }
+        }
+    }
+    res
+}
+
+fn get_chaining_hints(
+    acc: &mut Vec<InlayHint>,
+    sema: &Semantics<RootDatabase>,
+    config: &InlayHintsConfig,
+    expr: ast::Expr,
+) -> Option<()> {
+    if !config.chaining_hints {
+        return None;
+    }
+
+    if matches!(expr, ast::Expr::RecordExpr(_)) {
+        return None;
+    }
+
+    let mut tokens = expr
+        .syntax()
+        .siblings_with_tokens(Direction::Next)
+        .filter_map(NodeOrToken::into_token)
+        .filter(|t| match t.kind() {
+            SyntaxKind::WHITESPACE if !t.text().contains('\n') => false,
+            SyntaxKind::COMMENT => false,
+            _ => true,
+        });
+
+    // Chaining can be defined as an expression whose next sibling tokens are newline and dot
+    // Ignoring extra whitespace and comments
+    let next = tokens.next()?.kind();
+    let next_next = tokens.next()?.kind();
+    if next == SyntaxKind::WHITESPACE && next_next == T![.] {
+        let ty = sema.type_of_expr(&expr)?;
+        if ty.is_unknown() {
+            return None;
+        }
+        if matches!(expr, ast::Expr::PathExpr(_)) {
+            if let Some(Adt::Struct(st)) = ty.as_adt() {
+                if st.fields(sema.db).is_empty() {
+                    return None;
+                }
+            }
+        }
+        let label = ty.display_truncated(sema.db, config.max_length).to_string();
+        acc.push(InlayHint {
+            range: expr.syntax().text_range(),
+            kind: InlayKind::ChainingHint,
+            label: label.into(),
+        });
+    }
+    Some(())
+}
+
+fn get_param_name_hints(
+    acc: &mut Vec<InlayHint>,
+    sema: &Semantics<RootDatabase>,
+    config: &InlayHintsConfig,
+    expr: ast::Expr,
+) -> Option<()> {
+    if !config.parameter_hints {
+        return None;
+    }
+
+    let args = match &expr {
+        ast::Expr::CallExpr(expr) => expr.arg_list()?.args(),
+        ast::Expr::MethodCallExpr(expr) => expr.arg_list()?.args(),
+        _ => return None,
+    };
+
+    let callable = get_callable(sema, &expr)?;
+    let hints = callable
+        .params(sema.db)
+        .into_iter()
+        .zip(args)
+        .filter_map(|((param, _ty), arg)| {
+            let param_name = match param? {
+                Either::Left(self_param) => self_param.to_string(),
+                Either::Right(pat) => match pat {
+                    ast::Pat::IdentPat(it) => it.name()?.to_string(),
+                    _ => return None,
+                },
+            };
+            Some((param_name, arg))
+        })
+        .filter(|(param_name, arg)| should_show_param_name_hint(sema, &callable, &param_name, &arg))
+        .map(|(param_name, arg)| InlayHint {
+            range: arg.syntax().text_range(),
+            kind: InlayKind::ParameterHint,
+            label: param_name.into(),
+        });
+
+    acc.extend(hints);
+    Some(())
+}
+
+fn get_bind_pat_hints(
+    acc: &mut Vec<InlayHint>,
+    sema: &Semantics<RootDatabase>,
+    config: &InlayHintsConfig,
+    pat: ast::IdentPat,
+) -> Option<()> {
+    if !config.type_hints {
+        return None;
+    }
+
+    let ty = sema.type_of_pat(&pat.clone().into())?;
+
+    if should_not_display_type_hint(sema.db, &pat, &ty) {
+        return None;
+    }
+
+    acc.push(InlayHint {
+        range: pat.syntax().text_range(),
+        kind: InlayKind::TypeHint,
+        label: ty.display_truncated(sema.db, config.max_length).to_string().into(),
+    });
+    Some(())
+}
+
+fn pat_is_enum_variant(db: &RootDatabase, bind_pat: &ast::IdentPat, pat_ty: &Type) -> bool {
+    if let Some(Adt::Enum(enum_data)) = pat_ty.as_adt() {
+        let pat_text = bind_pat.to_string();
+        enum_data
+            .variants(db)
+            .into_iter()
+            .map(|variant| variant.name(db).to_string())
+            .any(|enum_name| enum_name == pat_text)
+    } else {
+        false
+    }
+}
+
+fn should_not_display_type_hint(
+    db: &RootDatabase,
+    bind_pat: &ast::IdentPat,
+    pat_ty: &Type,
+) -> bool {
+    if pat_ty.is_unknown() {
+        return true;
+    }
+
+    if let Some(Adt::Struct(s)) = pat_ty.as_adt() {
+        if s.fields(db).is_empty() && s.name(db).to_string() == bind_pat.to_string() {
+            return true;
+        }
+    }
+
+    for node in bind_pat.syntax().ancestors() {
+        match_ast! {
+            match node {
+                ast::LetStmt(it) => {
+                    return it.ty().is_some()
+                },
+                ast::Param(it) => {
+                    return it.ty().is_some()
+                },
+                ast::MatchArm(_it) => {
+                    return pat_is_enum_variant(db, bind_pat, pat_ty);
+                },
+                ast::IfExpr(it) => {
+                    return it.condition().and_then(|condition| condition.pat()).is_some()
+                        && pat_is_enum_variant(db, bind_pat, pat_ty);
+                },
+                ast::WhileExpr(it) => {
+                    return it.condition().and_then(|condition| condition.pat()).is_some()
+                        && pat_is_enum_variant(db, bind_pat, pat_ty);
+                },
+                _ => (),
+            }
+        }
+    }
+    false
+}
+
+fn should_show_param_name_hint(
+    sema: &Semantics<RootDatabase>,
+    callable: &Callable,
+    param_name: &str,
+    argument: &ast::Expr,
+) -> bool {
+    let param_name = param_name.trim_start_matches('_');
+    let fn_name = match callable.kind() {
+        hir::CallableKind::Function(it) => Some(it.name(sema.db).to_string()),
+        hir::CallableKind::TupleStruct(_)
+        | hir::CallableKind::TupleEnumVariant(_)
+        | hir::CallableKind::Closure => None,
+    };
+    if param_name.is_empty()
+        || Some(param_name) == fn_name.as_ref().map(|s| s.trim_start_matches('_'))
+        || is_argument_similar_to_param_name(sema, argument, param_name)
+        || param_name.starts_with("ra_fixture")
+    {
+        return false;
+    }
+
+    // avoid displaying hints for common functions like map, filter, etc.
+    // or other obvious words used in std
+    !(callable.n_params() == 1 && is_obvious_param(param_name))
+}
+
+fn is_argument_similar_to_param_name(
+    sema: &Semantics<RootDatabase>,
+    argument: &ast::Expr,
+    param_name: &str,
+) -> bool {
+    if is_enum_name_similar_to_param_name(sema, argument, param_name) {
+        return true;
+    }
+    match get_string_representation(argument) {
+        None => false,
+        Some(repr) => {
+            let argument_string = repr.trim_start_matches('_');
+            argument_string.starts_with(param_name) || argument_string.ends_with(param_name)
+        }
+    }
+}
+
+fn is_enum_name_similar_to_param_name(
+    sema: &Semantics<RootDatabase>,
+    argument: &ast::Expr,
+    param_name: &str,
+) -> bool {
+    match sema.type_of_expr(argument).and_then(|t| t.as_adt()) {
+        Some(Adt::Enum(e)) => to_lower_snake_case(&e.name(sema.db).to_string()) == param_name,
+        _ => false,
+    }
+}
+
+fn get_string_representation(expr: &ast::Expr) -> Option<String> {
+    match expr {
+        ast::Expr::MethodCallExpr(method_call_expr) => {
+            Some(method_call_expr.name_ref()?.to_string())
+        }
+        ast::Expr::RefExpr(ref_expr) => get_string_representation(&ref_expr.expr()?),
+        _ => Some(expr.to_string()),
+    }
+}
+
+fn is_obvious_param(param_name: &str) -> bool {
+    let is_obvious_param_name =
+        matches!(param_name, "predicate" | "value" | "pat" | "rhs" | "other");
+    param_name.len() == 1 || is_obvious_param_name
+}
+
+fn get_callable(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<Callable> {
+    match expr {
+        ast::Expr::CallExpr(expr) => sema.type_of_expr(&expr.expr()?)?.as_callable(sema.db),
+        ast::Expr::MethodCallExpr(expr) => sema.resolve_method_call_as_callable(expr),
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::extract_annotations;
+
+    use crate::{inlay_hints::InlayHintsConfig, mock_analysis::single_file};
+
+    fn check(ra_fixture: &str) {
+        check_with_config(InlayHintsConfig::default(), ra_fixture);
+    }
+
+    fn check_with_config(config: InlayHintsConfig, ra_fixture: &str) {
+        let (analysis, file_id) = single_file(ra_fixture);
+        let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
+        let inlay_hints = analysis.inlay_hints(file_id, &config).unwrap();
+        let actual =
+            inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
+        assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
+    }
+
+    fn check_expect(config: InlayHintsConfig, ra_fixture: &str, expect: Expect) {
+        let (analysis, file_id) = single_file(ra_fixture);
+        let inlay_hints = analysis.inlay_hints(file_id, &config).unwrap();
+        expect.assert_debug_eq(&inlay_hints)
+    }
+
+    #[test]
+    fn param_hints_only() {
+        check_with_config(
+            InlayHintsConfig {
+                parameter_hints: true,
+                type_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
+            r#"
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(
+        4,
+      //^ a
+        4,
+      //^ b
+    );
+}"#,
+        );
+    }
+
+    #[test]
+    fn hints_disabled() {
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: false,
+                parameter_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
+            r#"
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(4, 4);
+}"#,
+        );
+    }
+
+    #[test]
+    fn type_hints_only() {
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: true,
+                parameter_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
+            r#"
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(4, 4);
+      //^^ i32
+}"#,
+        );
+    }
+
+    #[test]
+    fn default_generic_types_should_not_be_displayed() {
+        check(
+            r#"
+struct Test<K, T = u8> { k: K, t: T }
+
+fn main() {
+    let zz = Test { t: 23u8, k: 33 };
+      //^^ Test<i32>
+    let zz_ref = &zz;
+      //^^^^^^ &Test<i32>
+    let test = || zz;
+      //^^^^ || -> Test<i32>
+}"#,
+        );
+    }
+
+    #[test]
+    fn let_statement() {
+        check(
+            r#"
+#[derive(PartialEq)]
+enum Option<T> { None, Some(T) }
+
+#[derive(PartialEq)]
+struct Test { a: Option<u32>, b: u8 }
+
+fn main() {
+    struct InnerStruct {}
+
+    let test = 54;
+      //^^^^ i32
+    let test: i32 = 33;
+    let mut test = 33;
+      //^^^^^^^^ i32
+    let _ = 22;
+    let test = "test";
+      //^^^^ &str
+    let test = InnerStruct {};
+
+    let test = unresolved();
+
+    let test = (42, 'a');
+      //^^^^ (i32, char)
+    let (a,    (b,     (c,)) = (2, (3, (9.2,));
+       //^ i32  ^ i32   ^ f64
+    let &x = &92;
+       //^ i32
+}"#,
+        );
+    }
+
+    #[test]
+    fn closure_parameters() {
+        check(
+            r#"
+fn main() {
+    let mut start = 0;
+      //^^^^^^^^^ i32
+    (0..2).for_each(|increment| { start += increment; });
+                   //^^^^^^^^^ i32
+
+    let multiply =
+      //^^^^^^^^ |…| -> i32
+      | a,     b| a * b
+      //^ i32  ^ i32
+    ;
+
+    let _: i32 = multiply(1, 2);
+    let multiply_ref = &multiply;
+      //^^^^^^^^^^^^ &|…| -> i32
+
+    let return_42 = || 42;
+      //^^^^^^^^^ || -> i32
+}"#,
+        );
+    }
+
+    #[test]
+    fn for_expression() {
+        check(
+            r#"
+fn main() {
+    let mut start = 0;
+      //^^^^^^^^^ i32
+    for increment in 0..2 { start += increment; }
+      //^^^^^^^^^ i32
+}"#,
+        );
+    }
+
+    #[test]
+    fn if_expr() {
+        check(
+            r#"
+enum Option<T> { None, Some(T) }
+use Option::*;
+
+struct Test { a: Option<u32>, b: u8 }
+
+fn main() {
+    let test = Some(Test { a: Some(3), b: 1 });
+      //^^^^ Option<Test>
+    if let None = &test {};
+    if let test = &test {};
+         //^^^^ &Option<Test>
+    if let Some(test) = &test {};
+              //^^^^ &Test
+    if let Some(Test { a,             b }) = &test {};
+                     //^ &Option<u32> ^ &u8
+    if let Some(Test { a: x,             b: y }) = &test {};
+                        //^ &Option<u32>    ^ &u8
+    if let Some(Test { a: Some(x),  b: y }) = &test {};
+                             //^ &u32  ^ &u8
+    if let Some(Test { a: None,  b: y }) = &test {};
+                                  //^ &u8
+    if let Some(Test { b: y, .. }) = &test {};
+                        //^ &u8
+    if test == None {}
+}"#,
+        );
+    }
+
+    #[test]
+    fn while_expr() {
+        check(
+            r#"
+enum Option<T> { None, Some(T) }
+use Option::*;
+
+struct Test { a: Option<u32>, b: u8 }
+
+fn main() {
+    let test = Some(Test { a: Some(3), b: 1 });
+      //^^^^ Option<Test>
+    while let Some(Test { a: Some(x),  b: y }) = &test {};
+                                //^ &u32  ^ &u8
+}"#,
+        );
+    }
+
+    #[test]
+    fn match_arm_list() {
+        check(
+            r#"
+enum Option<T> { None, Some(T) }
+use Option::*;
+
+struct Test { a: Option<u32>, b: u8 }
+
+fn main() {
+    match Some(Test { a: Some(3), b: 1 }) {
+        None => (),
+        test => (),
+      //^^^^ Option<Test>
+        Some(Test { a: Some(x), b: y }) => (),
+                          //^ u32  ^ u8
+        _ => {}
+    }
+}"#,
+        );
+    }
+
+    #[test]
+    fn hint_truncation() {
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
+            r#"
+struct Smol<T>(T);
+
+struct VeryLongOuterName<T>(T);
+
+fn main() {
+    let a = Smol(0u32);
+      //^ Smol<u32>
+    let b = VeryLongOuterName(0usize);
+      //^ VeryLongOuterName<…>
+    let c = Smol(Smol(0u32))
+      //^ Smol<Smol<…>>
+}"#,
+        );
+    }
+
+    #[test]
+    fn function_call_parameter_hint() {
+        check(
+            r#"
+enum Option<T> { None, Some(T) }
+use Option::*;
+
+struct FileId {}
+struct SmolStr {}
+
+struct TextRange {}
+struct SyntaxKind {}
+struct NavigationTarget {}
+
+struct Test {}
+
+impl Test {
+    fn method(&self, mut param: i32) -> i32 { param * 2 }
+
+    fn from_syntax(
+        file_id: FileId,
+        name: SmolStr,
+        focus_range: Option<TextRange>,
+        full_range: TextRange,
+        kind: SyntaxKind,
+        docs: Option<String>,
+    ) -> NavigationTarget {
+        NavigationTarget {}
+    }
+}
+
+fn test_func(mut foo: i32, bar: i32, msg: &str, _: i32, last: i32) -> i32 {
+    foo + bar
+}
+
+fn main() {
+    let not_literal = 1;
+      //^^^^^^^^^^^ i32
+    let _: i32 = test_func(1,    2,      "hello", 3,  not_literal);
+                         //^ foo ^ bar   ^^^^^^^ msg  ^^^^^^^^^^^ last
+    let t: Test = Test {};
+    t.method(123);
+           //^^^ param
+    Test::method(&t,      3456);
+               //^^ &self ^^^^ param
+    Test::from_syntax(
+        FileId {},
+      //^^^^^^^^^ file_id
+        "impl".into(),
+      //^^^^^^^^^^^^^ name
+        None,
+      //^^^^ focus_range
+        TextRange {},
+      //^^^^^^^^^^^^ full_range
+        SyntaxKind {},
+      //^^^^^^^^^^^^^ kind
+        None,
+      //^^^^ docs
+    );
+}"#,
+        );
+    }
+
+    #[test]
+    fn omitted_parameters_hints_heuristics() {
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
+            r#"
+fn map(f: i32) {}
+fn filter(predicate: i32) {}
+
+struct TestVarContainer {
+    test_var: i32,
+}
+
+impl TestVarContainer {
+    fn test_var(&self) -> i32 {
+        self.test_var
+    }
+}
+
+struct Test {}
+
+impl Test {
+    fn map(self, f: i32) -> Self {
+        self
+    }
+
+    fn filter(self, predicate: i32) -> Self {
+        self
+    }
+
+    fn field(self, value: i32) -> Self {
+        self
+    }
+
+    fn no_hints_expected(&self, _: i32, test_var: i32) {}
+
+    fn frob(&self, frob: bool) {}
+}
+
+struct Param {}
+
+fn different_order(param: &Param) {}
+fn different_order_mut(param: &mut Param) {}
+fn has_underscore(_param: bool) {}
+fn enum_matches_param_name(completion_kind: CompletionKind) {}
+fn param_destructuring_omitted_1((a, b): (u32, u32)) {}
+fn param_destructuring_omitted_2(TestVarContainer { test_var: _ }: TestVarContainer) {}
+
+fn twiddle(twiddle: bool) {}
+fn doo(_doo: bool) {}
+
+enum CompletionKind {
+    Keyword,
+}
+
+fn main() {
+    let container: TestVarContainer = TestVarContainer { test_var: 42 };
+    let test: Test = Test {};
+
+    map(22);
+    filter(33);
+
+    let test_processed: Test = test.map(1).filter(2).field(3);
+
+    let test_var: i32 = 55;
+    test_processed.no_hints_expected(22, test_var);
+    test_processed.no_hints_expected(33, container.test_var);
+    test_processed.no_hints_expected(44, container.test_var());
+    test_processed.frob(false);
+
+    twiddle(true);
+    doo(true);
+
+    let mut param_begin: Param = Param {};
+    different_order(&param_begin);
+    different_order(&mut param_begin);
+
+    let param: bool = true;
+    has_underscore(param);
+
+    enum_matches_param_name(CompletionKind::Keyword);
+
+    let a: f64 = 7.0;
+    let b: f64 = 4.0;
+    let _: f64 = a.div_euclid(b);
+    let _: f64 = a.abs_sub(b);
+
+    let range: (u32, u32) = (3, 5);
+    param_destructuring_omitted_1(range);
+    param_destructuring_omitted_2(container);
+}"#,
+        );
+    }
+
+    #[test]
+    fn unit_structs_have_no_type_hints() {
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+use Result::*;
+
+struct SyntheticSyntax;
+
+fn main() {
+    match Ok(()) {
+        Ok(_) => (),
+        Err(SyntheticSyntax) => (),
+    }
+}"#,
+        );
+    }
+
+    #[test]
+    fn chaining_hints_ignore_comments() {
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
+            r#"
+struct A(B);
+impl A { fn into_b(self) -> B { self.0 } }
+struct B(C);
+impl B { fn into_c(self) -> C { self.0 } }
+struct C;
+
+fn main() {
+    let c = A(B(C))
+        .into_b() // This is a comment
+        .into_c();
+}
+"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 147..172,
+                        kind: ChainingHint,
+                        label: "B",
+                    },
+                    InlayHint {
+                        range: 147..154,
+                        kind: ChainingHint,
+                        label: "A",
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn chaining_hints_without_newlines() {
+        check_with_config(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
+            r#"
+struct A(B);
+impl A { fn into_b(self) -> B { self.0 } }
+struct B(C);
+impl B { fn into_c(self) -> C { self.0 } }
+struct C;
+
+fn main() {
+    let c = A(B(C)).into_b().into_c();
+}"#,
+        );
+    }
+
+    #[test]
+    fn struct_access_chaining_hints() {
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
+            r#"
+struct A { pub b: B }
+struct B { pub c: C }
+struct C(pub bool);
+struct D;
+
+impl D {
+    fn foo(&self) -> i32 { 42 }
+}
+
+fn main() {
+    let x = A { b: B { c: C(true) } }
+        .b
+        .c
+        .0;
+    let x = D
+        .foo();
+}"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 143..190,
+                        kind: ChainingHint,
+                        label: "C",
+                    },
+                    InlayHint {
+                        range: 143..179,
+                        kind: ChainingHint,
+                        label: "B",
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn generic_chaining_hints() {
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
+            r#"
+struct A<T>(T);
+struct B<T>(T);
+struct C<T>(T);
+struct X<T,R>(T, R);
+
+impl<T> A<T> {
+    fn new(t: T) -> Self { A(t) }
+    fn into_b(self) -> B<T> { B(self.0) }
+}
+impl<T> B<T> {
+    fn into_c(self) -> C<T> { C(self.0) }
+}
+fn main() {
+    let c = A::new(X(42, true))
+        .into_b()
+        .into_c();
+}
+"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 246..283,
+                        kind: ChainingHint,
+                        label: "B<X<i32, bool>>",
+                    },
+                    InlayHint {
+                        range: 246..265,
+                        kind: ChainingHint,
+                        label: "A<X<i32, bool>>",
+                    },
+                ]
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
new file mode 100644
index 000000000..e37702acd
--- /dev/null
+++ b/crates/ide/src/join_lines.rs
@@ -0,0 +1,773 @@
+use assists::utils::extract_trivial_expression;
+use itertools::Itertools;
+use syntax::{
+    algo::{find_covering_element, non_trivia_sibling},
+    ast::{self, AstNode, AstToken},
+    Direction, NodeOrToken, SourceFile,
+    SyntaxKind::{self, USE_TREE, WHITESPACE},
+    SyntaxNode, SyntaxToken, TextRange, TextSize, T,
+};
+use text_edit::{TextEdit, TextEditBuilder};
+
+// Feature: Join Lines
+//
+// Join selected lines into one, smartly fixing up whitespace, trailing commas, and braces.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Join lines**
+// |===
+pub fn join_lines(file: &SourceFile, range: TextRange) -> TextEdit {
+    let range = if range.is_empty() {
+        let syntax = file.syntax();
+        let text = syntax.text().slice(range.start()..);
+        let pos = match text.find_char('\n') {
+            None => return TextEdit::builder().finish(),
+            Some(pos) => pos,
+        };
+        TextRange::at(range.start() + pos, TextSize::of('\n'))
+    } else {
+        range
+    };
+
+    let node = match find_covering_element(file.syntax(), range) {
+        NodeOrToken::Node(node) => node,
+        NodeOrToken::Token(token) => token.parent(),
+    };
+    let mut edit = TextEdit::builder();
+    for token in node.descendants_with_tokens().filter_map(|it| it.into_token()) {
+        let range = match range.intersect(token.text_range()) {
+            Some(range) => range,
+            None => continue,
+        } - token.text_range().start();
+        let text = token.text();
+        for (pos, _) in text[range].bytes().enumerate().filter(|&(_, b)| b == b'\n') {
+            let pos: TextSize = (pos as u32).into();
+            let off = token.text_range().start() + range.start() + pos;
+            if !edit.invalidates_offset(off) {
+                remove_newline(&mut edit, &token, off);
+            }
+        }
+    }
+
+    edit.finish()
+}
+
+fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextSize) {
+    if token.kind() != WHITESPACE || token.text().bytes().filter(|&b| b == b'\n').count() != 1 {
+        // The node is either the first or the last in the file
+        let suff = &token.text()[TextRange::new(
+            offset - token.text_range().start() + TextSize::of('\n'),
+            TextSize::of(token.text().as_str()),
+        )];
+        let spaces = suff.bytes().take_while(|&b| b == b' ').count();
+
+        edit.replace(TextRange::at(offset, ((spaces + 1) as u32).into()), " ".to_string());
+        return;
+    }
+
+    // The node is between two other nodes
+    let prev = token.prev_sibling_or_token().unwrap();
+    let next = token.next_sibling_or_token().unwrap();
+    if is_trailing_comma(prev.kind(), next.kind()) {
+        // Removes: trailing comma, newline (incl. surrounding whitespace)
+        edit.delete(TextRange::new(prev.text_range().start(), token.text_range().end()));
+        return;
+    }
+    if prev.kind() == T![,] && next.kind() == T!['}'] {
+        // Removes: comma, newline (incl. surrounding whitespace)
+        let space = if let Some(left) = prev.prev_sibling_or_token() {
+            compute_ws(left.kind(), next.kind())
+        } else {
+            " "
+        };
+        edit.replace(
+            TextRange::new(prev.text_range().start(), token.text_range().end()),
+            space.to_string(),
+        );
+        return;
+    }
+
+    if let (Some(_), Some(next)) = (
+        prev.as_token().cloned().and_then(ast::Comment::cast),
+        next.as_token().cloned().and_then(ast::Comment::cast),
+    ) {
+        // Removes: newline (incl. surrounding whitespace), start of the next comment
+        edit.delete(TextRange::new(
+            token.text_range().start(),
+            next.syntax().text_range().start() + TextSize::of(next.prefix()),
+        ));
+        return;
+    }
+
+    // Special case that turns something like:
+    //
+    // ```
+    // my_function({<|>
+    //    <some-expr>
+    // })
+    // ```
+    //
+    // into `my_function(<some-expr>)`
+    if join_single_expr_block(edit, token).is_some() {
+        return;
+    }
+    // ditto for
+    //
+    // ```
+    // use foo::{<|>
+    //    bar
+    // };
+    // ```
+    if join_single_use_tree(edit, token).is_some() {
+        return;
+    }
+
+    // Remove newline but add a computed amount of whitespace characters
+    edit.replace(token.text_range(), compute_ws(prev.kind(), next.kind()).to_string());
+}
+
+fn has_comma_after(node: &SyntaxNode) -> bool {
+    match non_trivia_sibling(node.clone().into(), Direction::Next) {
+        Some(n) => n.kind() == T![,],
+        _ => false,
+    }
+}
+
+fn join_single_expr_block(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Option<()> {
+    let block_expr = ast::BlockExpr::cast(token.parent())?;
+    if !block_expr.is_standalone() {
+        return None;
+    }
+    let expr = extract_trivial_expression(&block_expr)?;
+
+    let block_range = block_expr.syntax().text_range();
+    let mut buf = expr.syntax().text().to_string();
+
+    // Match block needs to have a comma after the block
+    if let Some(match_arm) = block_expr.syntax().parent().and_then(ast::MatchArm::cast) {
+        if !has_comma_after(match_arm.syntax()) {
+            buf.push(',');
+        }
+    }
+
+    edit.replace(block_range, buf);
+
+    Some(())
+}
+
+fn join_single_use_tree(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Option<()> {
+    let use_tree_list = ast::UseTreeList::cast(token.parent())?;
+    let (tree,) = use_tree_list.use_trees().collect_tuple()?;
+    edit.replace(use_tree_list.syntax().text_range(), tree.syntax().text().to_string());
+    Some(())
+}
+
+fn is_trailing_comma(left: SyntaxKind, right: SyntaxKind) -> bool {
+    matches!((left, right), (T![,], T![')']) | (T![,], T![']']))
+}
+
+fn compute_ws(left: SyntaxKind, right: SyntaxKind) -> &'static str {
+    match left {
+        T!['('] | T!['['] => return "",
+        T!['{'] => {
+            if let USE_TREE = right {
+                return "";
+            }
+        }
+        _ => (),
+    }
+    match right {
+        T![')'] | T![']'] => return "",
+        T!['}'] => {
+            if let USE_TREE = left {
+                return "";
+            }
+        }
+        T![.] => return "",
+        _ => (),
+    }
+    " "
+}
+
+#[cfg(test)]
+mod tests {
+    use syntax::SourceFile;
+    use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
+
+    use super::*;
+
+    fn check_join_lines(before: &str, after: &str) {
+        let (before_cursor_pos, before) = extract_offset(before);
+        let file = SourceFile::parse(&before).ok().unwrap();
+
+        let range = TextRange::empty(before_cursor_pos);
+        let result = join_lines(&file, range);
+
+        let actual = {
+            let mut actual = before.to_string();
+            result.apply(&mut actual);
+            actual
+        };
+        let actual_cursor_pos = result
+            .apply_to_offset(before_cursor_pos)
+            .expect("cursor position is affected by the edit");
+        let actual = add_cursor(&actual, actual_cursor_pos);
+        assert_eq_text!(after, &actual);
+    }
+
+    #[test]
+    fn test_join_lines_comma() {
+        check_join_lines(
+            r"
+fn foo() {
+    <|>foo(1,
+    )
+}
+",
+            r"
+fn foo() {
+    <|>foo(1)
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_lambda_block() {
+        check_join_lines(
+            r"
+pub fn reparse(&self, edit: &AtomTextEdit) -> File {
+    <|>self.incremental_reparse(edit).unwrap_or_else(|| {
+        self.full_reparse(edit)
+    })
+}
+",
+            r"
+pub fn reparse(&self, edit: &AtomTextEdit) -> File {
+    <|>self.incremental_reparse(edit).unwrap_or_else(|| self.full_reparse(edit))
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_block() {
+        check_join_lines(
+            r"
+fn foo() {
+    foo(<|>{
+        92
+    })
+}",
+            r"
+fn foo() {
+    foo(<|>92)
+}",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_diverging_block() {
+        let before = r"
+            fn foo() {
+                loop {
+                    match x {
+                        92 => <|>{
+                            continue;
+                        }
+                    }
+                }
+            }
+        ";
+        let after = r"
+            fn foo() {
+                loop {
+                    match x {
+                        92 => <|>continue,
+                    }
+                }
+            }
+        ";
+        check_join_lines(before, after);
+    }
+
+    #[test]
+    fn join_lines_adds_comma_for_block_in_match_arm() {
+        check_join_lines(
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>{
+            u.foo()
+        }
+        Err(v) => v,
+    }
+}",
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>u.foo(),
+        Err(v) => v,
+    }
+}",
+        );
+    }
+
+    #[test]
+    fn join_lines_multiline_in_block() {
+        check_join_lines(
+            r"
+fn foo() {
+    match ty {
+        <|> Some(ty) => {
+            match ty {
+                _ => false,
+            }
+        }
+        _ => true,
+    }
+}
+",
+            r"
+fn foo() {
+    match ty {
+        <|> Some(ty) => match ty {
+                _ => false,
+            },
+        _ => true,
+    }
+}
+",
+        );
+    }
+
+    #[test]
+    fn join_lines_keeps_comma_for_block_in_match_arm() {
+        // We already have a comma
+        check_join_lines(
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>{
+            u.foo()
+        },
+        Err(v) => v,
+    }
+}",
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>u.foo(),
+        Err(v) => v,
+    }
+}",
+        );
+
+        // comma with whitespace between brace and ,
+        check_join_lines(
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>{
+            u.foo()
+        }    ,
+        Err(v) => v,
+    }
+}",
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>u.foo()    ,
+        Err(v) => v,
+    }
+}",
+        );
+
+        // comma with newline between brace and ,
+        check_join_lines(
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>{
+            u.foo()
+        }
+        ,
+        Err(v) => v,
+    }
+}",
+            r"
+fn foo(e: Result<U, V>) {
+    match e {
+        Ok(u) => <|>u.foo()
+        ,
+        Err(v) => v,
+    }
+}",
+        );
+    }
+
+    #[test]
+    fn join_lines_keeps_comma_with_single_arg_tuple() {
+        // A single arg tuple
+        check_join_lines(
+            r"
+fn foo() {
+    let x = (<|>{
+       4
+    },);
+}",
+            r"
+fn foo() {
+    let x = (<|>4,);
+}",
+        );
+
+        // single arg tuple with whitespace between brace and comma
+        check_join_lines(
+            r"
+fn foo() {
+    let x = (<|>{
+       4
+    }   ,);
+}",
+            r"
+fn foo() {
+    let x = (<|>4   ,);
+}",
+        );
+
+        // single arg tuple with newline between brace and comma
+        check_join_lines(
+            r"
+fn foo() {
+    let x = (<|>{
+       4
+    }
+    ,);
+}",
+            r"
+fn foo() {
+    let x = (<|>4
+    ,);
+}",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_use_items_left() {
+        // No space after the '{'
+        check_join_lines(
+            r"
+<|>use syntax::{
+    TextSize, TextRange,
+};",
+            r"
+<|>use syntax::{TextSize, TextRange,
+};",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_use_items_right() {
+        // No space after the '}'
+        check_join_lines(
+            r"
+use syntax::{
+<|>    TextSize, TextRange
+};",
+            r"
+use syntax::{
+<|>    TextSize, TextRange};",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_use_items_right_comma() {
+        // No space after the '}'
+        check_join_lines(
+            r"
+use syntax::{
+<|>    TextSize, TextRange,
+};",
+            r"
+use syntax::{
+<|>    TextSize, TextRange};",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_use_tree() {
+        check_join_lines(
+            r"
+use syntax::{
+    algo::<|>{
+        find_token_at_offset,
+    },
+    ast,
+};",
+            r"
+use syntax::{
+    algo::<|>find_token_at_offset,
+    ast,
+};",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_normal_comments() {
+        check_join_lines(
+            r"
+fn foo() {
+    // Hello<|>
+    // world!
+}
+",
+            r"
+fn foo() {
+    // Hello<|> world!
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_doc_comments() {
+        check_join_lines(
+            r"
+fn foo() {
+    /// Hello<|>
+    /// world!
+}
+",
+            r"
+fn foo() {
+    /// Hello<|> world!
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_mod_comments() {
+        check_join_lines(
+            r"
+fn foo() {
+    //! Hello<|>
+    //! world!
+}
+",
+            r"
+fn foo() {
+    //! Hello<|> world!
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_multiline_comments_1() {
+        check_join_lines(
+            r"
+fn foo() {
+    // Hello<|>
+    /* world! */
+}
+",
+            r"
+fn foo() {
+    // Hello<|> world! */
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_multiline_comments_2() {
+        check_join_lines(
+            r"
+fn foo() {
+    // The<|>
+    /* quick
+    brown
+    fox! */
+}
+",
+            r"
+fn foo() {
+    // The<|> quick
+    brown
+    fox! */
+}
+",
+        );
+    }
+
+    fn check_join_lines_sel(before: &str, after: &str) {
+        let (sel, before) = extract_range(before);
+        let parse = SourceFile::parse(&before);
+        let result = join_lines(&parse.tree(), sel);
+        let actual = {
+            let mut actual = before.to_string();
+            result.apply(&mut actual);
+            actual
+        };
+        assert_eq_text!(after, &actual);
+    }
+
+    #[test]
+    fn test_join_lines_selection_fn_args() {
+        check_join_lines_sel(
+            r"
+fn foo() {
+    <|>foo(1,
+        2,
+        3,
+    <|>)
+}
+    ",
+            r"
+fn foo() {
+    foo(1, 2, 3)
+}
+    ",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_selection_struct() {
+        check_join_lines_sel(
+            r"
+struct Foo <|>{
+    f: u32,
+}<|>
+    ",
+            r"
+struct Foo { f: u32 }
+    ",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_selection_dot_chain() {
+        check_join_lines_sel(
+            r"
+fn foo() {
+    join(<|>type_params.type_params()
+            .filter_map(|it| it.name())
+            .map(|it| it.text())<|>)
+}",
+            r"
+fn foo() {
+    join(type_params.type_params().filter_map(|it| it.name()).map(|it| it.text()))
+}",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_selection_lambda_block_body() {
+        check_join_lines_sel(
+            r"
+pub fn handle_find_matching_brace() {
+    params.offsets
+        .map(|offset| <|>{
+            world.analysis().matching_brace(&file, offset).unwrap_or(offset)
+        }<|>)
+        .collect();
+}",
+            r"
+pub fn handle_find_matching_brace() {
+    params.offsets
+        .map(|offset| world.analysis().matching_brace(&file, offset).unwrap_or(offset))
+        .collect();
+}",
+        );
+    }
+
+    #[test]
+    fn test_join_lines_commented_block() {
+        check_join_lines(
+            r"
+fn main() {
+    let _ = {
+        // <|>foo
+        // bar
+        92
+    };
+}
+        ",
+            r"
+fn main() {
+    let _ = {
+        // <|>foo bar
+        92
+    };
+}
+        ",
+        )
+    }
+
+    #[test]
+    fn join_lines_mandatory_blocks_block() {
+        check_join_lines(
+            r"
+<|>fn foo() {
+    92
+}
+        ",
+            r"
+<|>fn foo() { 92
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>if true {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>if true { 92
+    }
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>loop {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>loop { 92
+    }
+}
+        ",
+        );
+
+        check_join_lines(
+            r"
+fn foo() {
+    <|>unsafe {
+        92
+    }
+}
+        ",
+            r"
+fn foo() {
+    <|>unsafe { 92
+    }
+}
+        ",
+        );
+    }
+}
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
new file mode 100644
index 000000000..eb6389529
--- /dev/null
+++ b/crates/ide/src/lib.rs
@@ -0,0 +1,542 @@
+//! ide crate provides "ide-centric" APIs for the rust-analyzer. That is,
+//! it generally operates with files and text ranges, and returns results as
+//! Strings, suitable for displaying to the human.
+//!
+//! What powers this API are the `RootDatabase` struct, which defines a `salsa`
+//! database, and the `hir` crate, where majority of the analysis happens.
+//! However, IDE specific bits of the analysis (most notably completion) happen
+//! in this crate.
+
+// For proving that RootDatabase is RefUnwindSafe.
+#![recursion_limit = "128"]
+
+#[allow(unused)]
+macro_rules! eprintln {
+    ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
+}
+
+pub mod mock_analysis;
+
+mod markup;
+mod prime_caches;
+mod display;
+
+mod call_hierarchy;
+mod call_info;
+mod completion;
+mod diagnostics;
+mod expand_macro;
+mod extend_selection;
+mod file_structure;
+mod folding_ranges;
+mod goto_definition;
+mod goto_implementation;
+mod goto_type_definition;
+mod hover;
+mod inlay_hints;
+mod join_lines;
+mod matching_brace;
+mod parent_module;
+mod references;
+mod runnables;
+mod status;
+mod syntax_highlighting;
+mod syntax_tree;
+mod typing;
+
+use std::sync::Arc;
+
+use base_db::{
+    salsa::{self, ParallelDatabase},
+    CheckCanceled, Env, FileLoader, FileSet, SourceDatabase, VfsPath,
+};
+use cfg::CfgOptions;
+use ide_db::{
+    symbol_index::{self, FileSymbol},
+    LineIndexDatabase,
+};
+use syntax::{SourceFile, TextRange, TextSize};
+
+use crate::display::ToNav;
+
+pub use crate::{
+    call_hierarchy::CallItem,
+    call_info::CallInfo,
+    completion::{
+        CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, InsertTextFormat,
+    },
+    diagnostics::Severity,
+    display::NavigationTarget,
+    expand_macro::ExpandedMacro,
+    file_structure::StructureNode,
+    folding_ranges::{Fold, FoldKind},
+    hover::{HoverAction, HoverConfig, HoverGotoTypeData, HoverResult},
+    inlay_hints::{InlayHint, InlayHintsConfig, InlayKind},
+    markup::Markup,
+    references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
+    runnables::{Runnable, RunnableKind, TestId},
+    syntax_highlighting::{
+        Highlight, HighlightModifier, HighlightModifiers, HighlightTag, HighlightedRange,
+    },
+};
+
+pub use assists::{Assist, AssistConfig, AssistId, AssistKind, ResolvedAssist};
+pub use base_db::{
+    Canceled, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRoot,
+    SourceRootId,
+};
+pub use hir::{Documentation, Semantics};
+pub use ide_db::{
+    change::AnalysisChange,
+    line_index::{LineCol, LineIndex},
+    search::SearchScope,
+    source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
+    symbol_index::Query,
+    RootDatabase,
+};
+pub use ssr::SsrError;
+pub use text_edit::{Indel, TextEdit};
+
+pub type Cancelable<T> = Result<T, Canceled>;
+
+#[derive(Debug)]
+pub struct Diagnostic {
+    pub message: String,
+    pub range: TextRange,
+    pub severity: Severity,
+    pub fix: Option<Fix>,
+}
+
+#[derive(Debug)]
+pub struct Fix {
+    pub label: String,
+    pub source_change: SourceChange,
+    /// Allows to trigger the fix only when the caret is in the range given
+    pub fix_trigger_range: TextRange,
+}
+
+impl Fix {
+    pub fn new(
+        label: impl Into<String>,
+        source_change: SourceChange,
+        fix_trigger_range: TextRange,
+    ) -> Self {
+        let label = label.into();
+        assert!(label.starts_with(char::is_uppercase) && !label.ends_with('.'));
+        Self { label, source_change, fix_trigger_range }
+    }
+}
+
+/// Info associated with a text range.
+#[derive(Debug)]
+pub struct RangeInfo<T> {
+    pub range: TextRange,
+    pub info: T,
+}
+
+impl<T> RangeInfo<T> {
+    pub fn new(range: TextRange, info: T) -> RangeInfo<T> {
+        RangeInfo { range, info }
+    }
+}
+
+/// `AnalysisHost` stores the current state of the world.
+#[derive(Debug)]
+pub struct AnalysisHost {
+    db: RootDatabase,
+}
+
+impl AnalysisHost {
+    pub fn new(lru_capacity: Option<usize>) -> AnalysisHost {
+        AnalysisHost { db: RootDatabase::new(lru_capacity) }
+    }
+
+    pub fn update_lru_capacity(&mut self, lru_capacity: Option<usize>) {
+        self.db.update_lru_capacity(lru_capacity);
+    }
+
+    /// Returns a snapshot of the current state, which you can query for
+    /// semantic information.
+    pub fn analysis(&self) -> Analysis {
+        Analysis { db: self.db.snapshot() }
+    }
+
+    /// Applies changes to the current state of the world. If there are
+    /// outstanding snapshots, they will be canceled.
+    pub fn apply_change(&mut self, change: AnalysisChange) {
+        self.db.apply_change(change)
+    }
+
+    pub fn maybe_collect_garbage(&mut self) {
+        self.db.maybe_collect_garbage();
+    }
+
+    pub fn collect_garbage(&mut self) {
+        self.db.collect_garbage();
+    }
+    /// NB: this clears the database
+    pub fn per_query_memory_usage(&mut self) -> Vec<(String, profile::Bytes)> {
+        self.db.per_query_memory_usage()
+    }
+    pub fn request_cancellation(&mut self) {
+        self.db.request_cancellation();
+    }
+    pub fn raw_database(&self) -> &RootDatabase {
+        &self.db
+    }
+    pub fn raw_database_mut(&mut self) -> &mut RootDatabase {
+        &mut self.db
+    }
+}
+
+impl Default for AnalysisHost {
+    fn default() -> AnalysisHost {
+        AnalysisHost::new(None)
+    }
+}
+
+/// Analysis is a snapshot of a world state at a moment in time. It is the main
+/// entry point for asking semantic information about the world. When the world
+/// state is advanced using `AnalysisHost::apply_change` method, all existing
+/// `Analysis` are canceled (most method return `Err(Canceled)`).
+#[derive(Debug)]
+pub struct Analysis {
+    db: salsa::Snapshot<RootDatabase>,
+}
+
+// As a general design guideline, `Analysis` API are intended to be independent
+// from the language server protocol. That is, when exposing some functionality
+// we should think in terms of "what API makes most sense" and not in terms of
+// "what types LSP uses". Although currently LSP is the only consumer of the
+// API, the API should in theory be usable as a library, or via a different
+// protocol.
+impl Analysis {
+    // Creates an analysis instance for a single file, without any extenal
+    // dependencies, stdlib support or ability to apply changes. See
+    // `AnalysisHost` for creating a fully-featured analysis.
+    pub fn from_single_file(text: String) -> (Analysis, FileId) {
+        let mut host = AnalysisHost::default();
+        let file_id = FileId(0);
+        let mut file_set = FileSet::default();
+        file_set.insert(file_id, VfsPath::new_virtual_path("/main.rs".to_string()));
+        let source_root = SourceRoot::new_local(file_set);
+
+        let mut change = AnalysisChange::new();
+        change.set_roots(vec![source_root]);
+        let mut crate_graph = CrateGraph::default();
+        // FIXME: cfg options
+        // Default to enable test for single file.
+        let mut cfg_options = CfgOptions::default();
+        cfg_options.insert_atom("test".into());
+        crate_graph.add_crate_root(
+            file_id,
+            Edition::Edition2018,
+            None,
+            cfg_options,
+            Env::default(),
+            Default::default(),
+        );
+        change.change_file(file_id, Some(Arc::new(text)));
+        change.set_crate_graph(crate_graph);
+        host.apply_change(change);
+        (host.analysis(), file_id)
+    }
+
+    /// Debug info about the current state of the analysis.
+    pub fn status(&self) -> Cancelable<String> {
+        self.with_db(|db| status::status(&*db))
+    }
+
+    pub fn prime_caches(&self, files: Vec<FileId>) -> Cancelable<()> {
+        self.with_db(|db| prime_caches::prime_caches(db, files))
+    }
+
+    /// Gets the text of the source file.
+    pub fn file_text(&self, file_id: FileId) -> Cancelable<Arc<String>> {
+        self.with_db(|db| db.file_text(file_id))
+    }
+
+    /// Gets the syntax tree of the file.
+    pub fn parse(&self, file_id: FileId) -> Cancelable<SourceFile> {
+        self.with_db(|db| db.parse(file_id).tree())
+    }
+
+    /// Gets the file's `LineIndex`: data structure to convert between absolute
+    /// offsets and line/column representation.
+    pub fn file_line_index(&self, file_id: FileId) -> Cancelable<Arc<LineIndex>> {
+        self.with_db(|db| db.line_index(file_id))
+    }
+
+    /// Selects the next syntactic nodes encompassing the range.
+    pub fn extend_selection(&self, frange: FileRange) -> Cancelable<TextRange> {
+        self.with_db(|db| extend_selection::extend_selection(db, frange))
+    }
+
+    /// Returns position of the matching brace (all types of braces are
+    /// supported).
+    pub fn matching_brace(&self, position: FilePosition) -> Cancelable<Option<TextSize>> {
+        self.with_db(|db| {
+            let parse = db.parse(position.file_id);
+            let file = parse.tree();
+            matching_brace::matching_brace(&file, position.offset)
+        })
+    }
+
+    /// Returns a syntax tree represented as `String`, for debug purposes.
+    // FIXME: use a better name here.
+    pub fn syntax_tree(
+        &self,
+        file_id: FileId,
+        text_range: Option<TextRange>,
+    ) -> Cancelable<String> {
+        self.with_db(|db| syntax_tree::syntax_tree(&db, file_id, text_range))
+    }
+
+    pub fn expand_macro(&self, position: FilePosition) -> Cancelable<Option<ExpandedMacro>> {
+        self.with_db(|db| expand_macro::expand_macro(db, position))
+    }
+
+    /// Returns an edit to remove all newlines in the range, cleaning up minor
+    /// stuff like trailing commas.
+    pub fn join_lines(&self, frange: FileRange) -> Cancelable<TextEdit> {
+        self.with_db(|db| {
+            let parse = db.parse(frange.file_id);
+            join_lines::join_lines(&parse.tree(), frange.range)
+        })
+    }
+
+    /// Returns an edit which should be applied when opening a new line, fixing
+    /// up minor stuff like continuing the comment.
+    /// The edit will be a snippet (with `$0`).
+    pub fn on_enter(&self, position: FilePosition) -> Cancelable<Option<TextEdit>> {
+        self.with_db(|db| typing::on_enter(&db, position))
+    }
+
+    /// Returns an edit which should be applied after a character was typed.
+    ///
+    /// This is useful for some on-the-fly fixups, like adding `;` to `let =`
+    /// automatically.
+    pub fn on_char_typed(
+        &self,
+        position: FilePosition,
+        char_typed: char,
+    ) -> Cancelable<Option<SourceChange>> {
+        // Fast path to not even parse the file.
+        if !typing::TRIGGER_CHARS.contains(char_typed) {
+            return Ok(None);
+        }
+        self.with_db(|db| typing::on_char_typed(&db, position, char_typed))
+    }
+
+    /// Returns a tree representation of symbols in the file. Useful to draw a
+    /// file outline.
+    pub fn file_structure(&self, file_id: FileId) -> Cancelable<Vec<StructureNode>> {
+        self.with_db(|db| file_structure::file_structure(&db.parse(file_id).tree()))
+    }
+
+    /// Returns a list of the places in the file where type hints can be displayed.
+    pub fn inlay_hints(
+        &self,
+        file_id: FileId,
+        config: &InlayHintsConfig,
+    ) -> Cancelable<Vec<InlayHint>> {
+        self.with_db(|db| inlay_hints::inlay_hints(db, file_id, config))
+    }
+
+    /// Returns the set of folding ranges.
+    pub fn folding_ranges(&self, file_id: FileId) -> Cancelable<Vec<Fold>> {
+        self.with_db(|db| folding_ranges::folding_ranges(&db.parse(file_id).tree()))
+    }
+
+    /// Fuzzy searches for a symbol.
+    pub fn symbol_search(&self, query: Query) -> Cancelable<Vec<NavigationTarget>> {
+        self.with_db(|db| {
+            symbol_index::world_symbols(db, query)
+                .into_iter()
+                .map(|s| s.to_nav(db))
+                .collect::<Vec<_>>()
+        })
+    }
+
+    /// Returns the definitions from the symbol at `position`.
+    pub fn goto_definition(
+        &self,
+        position: FilePosition,
+    ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
+        self.with_db(|db| goto_definition::goto_definition(db, position))
+    }
+
+    /// Returns the impls from the symbol at `position`.
+    pub fn goto_implementation(
+        &self,
+        position: FilePosition,
+    ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
+        self.with_db(|db| goto_implementation::goto_implementation(db, position))
+    }
+
+    /// Returns the type definitions for the symbol at `position`.
+    pub fn goto_type_definition(
+        &self,
+        position: FilePosition,
+    ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
+        self.with_db(|db| goto_type_definition::goto_type_definition(db, position))
+    }
+
+    /// Finds all usages of the reference at point.
+    pub fn find_all_refs(
+        &self,
+        position: FilePosition,
+        search_scope: Option<SearchScope>,
+    ) -> Cancelable<Option<ReferenceSearchResult>> {
+        self.with_db(|db| {
+            references::find_all_refs(&Semantics::new(db), position, search_scope).map(|it| it.info)
+        })
+    }
+
+    /// Returns a short text describing element at position.
+    pub fn hover(&self, position: FilePosition) -> Cancelable<Option<RangeInfo<HoverResult>>> {
+        self.with_db(|db| hover::hover(db, position))
+    }
+
+    /// Computes parameter information for the given call expression.
+    pub fn call_info(&self, position: FilePosition) -> Cancelable<Option<CallInfo>> {
+        self.with_db(|db| call_info::call_info(db, position))
+    }
+
+    /// Computes call hierarchy candidates for the given file position.
+    pub fn call_hierarchy(
+        &self,
+        position: FilePosition,
+    ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
+        self.with_db(|db| call_hierarchy::call_hierarchy(db, position))
+    }
+
+    /// Computes incoming calls for the given file position.
+    pub fn incoming_calls(&self, position: FilePosition) -> Cancelable<Option<Vec<CallItem>>> {
+        self.with_db(|db| call_hierarchy::incoming_calls(db, position))
+    }
+
+    /// Computes incoming calls for the given file position.
+    pub fn outgoing_calls(&self, position: FilePosition) -> Cancelable<Option<Vec<CallItem>>> {
+        self.with_db(|db| call_hierarchy::outgoing_calls(db, position))
+    }
+
+    /// Returns a `mod name;` declaration which created the current module.
+    pub fn parent_module(&self, position: FilePosition) -> Cancelable<Vec<NavigationTarget>> {
+        self.with_db(|db| parent_module::parent_module(db, position))
+    }
+
+    /// Returns crates this file belongs too.
+    pub fn crate_for(&self, file_id: FileId) -> Cancelable<Vec<CrateId>> {
+        self.with_db(|db| parent_module::crate_for(db, file_id))
+    }
+
+    /// Returns the edition of the given crate.
+    pub fn crate_edition(&self, crate_id: CrateId) -> Cancelable<Edition> {
+        self.with_db(|db| db.crate_graph()[crate_id].edition)
+    }
+
+    /// Returns the root file of the given crate.
+    pub fn crate_root(&self, crate_id: CrateId) -> Cancelable<FileId> {
+        self.with_db(|db| db.crate_graph()[crate_id].root_file_id)
+    }
+
+    /// Returns the set of possible targets to run for the current file.
+    pub fn runnables(&self, file_id: FileId) -> Cancelable<Vec<Runnable>> {
+        self.with_db(|db| runnables::runnables(db, file_id))
+    }
+
+    /// Computes syntax highlighting for the given file
+    pub fn highlight(&self, file_id: FileId) -> Cancelable<Vec<HighlightedRange>> {
+        self.with_db(|db| syntax_highlighting::highlight(db, file_id, None, false))
+    }
+
+    /// Computes syntax highlighting for the given file range.
+    pub fn highlight_range(&self, frange: FileRange) -> Cancelable<Vec<HighlightedRange>> {
+        self.with_db(|db| {
+            syntax_highlighting::highlight(db, frange.file_id, Some(frange.range), false)
+        })
+    }
+
+    /// Computes syntax highlighting for the given file.
+    pub fn highlight_as_html(&self, file_id: FileId, rainbow: bool) -> Cancelable<String> {
+        self.with_db(|db| syntax_highlighting::highlight_as_html(db, file_id, rainbow))
+    }
+
+    /// Computes completions at the given position.
+    pub fn completions(
+        &self,
+        config: &CompletionConfig,
+        position: FilePosition,
+    ) -> Cancelable<Option<Vec<CompletionItem>>> {
+        self.with_db(|db| completion::completions(db, config, position).map(Into::into))
+    }
+
+    /// Computes resolved assists with source changes for the given position.
+    pub fn resolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<ResolvedAssist>> {
+        self.with_db(|db| assists::Assist::resolved(db, config, frange))
+    }
+
+    /// Computes unresolved assists (aka code actions aka intentions) for the given
+    /// position.
+    pub fn unresolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<Assist>> {
+        self.with_db(|db| Assist::unresolved(db, config, frange))
+    }
+
+    /// Computes the set of diagnostics for the given file.
+    pub fn diagnostics(
+        &self,
+        file_id: FileId,
+        enable_experimental: bool,
+    ) -> Cancelable<Vec<Diagnostic>> {
+        self.with_db(|db| diagnostics::diagnostics(db, file_id, enable_experimental))
+    }
+
+    /// Returns the edit required to rename reference at the position to the new
+    /// name.
+    pub fn rename(
+        &self,
+        position: FilePosition,
+        new_name: &str,
+    ) -> Cancelable<Option<RangeInfo<SourceChange>>> {
+        self.with_db(|db| references::rename(db, position, new_name))
+    }
+
+    pub fn structural_search_replace(
+        &self,
+        query: &str,
+        parse_only: bool,
+        resolve_context: FilePosition,
+        selections: Vec<FileRange>,
+    ) -> Cancelable<Result<SourceChange, SsrError>> {
+        self.with_db(|db| {
+            let rule: ssr::SsrRule = query.parse()?;
+            let mut match_finder = ssr::MatchFinder::in_context(db, resolve_context, selections);
+            match_finder.add_rule(rule)?;
+            let edits = if parse_only { Vec::new() } else { match_finder.edits() };
+            Ok(SourceChange::from(edits))
+        })
+    }
+
+    /// Performs an operation on that may be Canceled.
+    fn with_db<F, T>(&self, f: F) -> Cancelable<T>
+    where
+        F: FnOnce(&RootDatabase) -> T + std::panic::UnwindSafe,
+    {
+        self.db.catch_canceled(f)
+    }
+}
+
+#[test]
+fn analysis_is_send() {
+    fn is_send<T: Send>() {}
+    is_send::<Analysis>();
+}
diff --git a/crates/ide/src/markup.rs b/crates/ide/src/markup.rs
new file mode 100644
index 000000000..60c193c40
--- /dev/null
+++ b/crates/ide/src/markup.rs
@@ -0,0 +1,38 @@
+//! Markdown formatting.
+//!
+//! Sometimes, we want to display a "rich text" in the UI. At the moment, we use
+//! markdown for this purpose. It doesn't feel like a right option, but that's
+//! what is used by LSP, so let's keep it simple.
+use std::fmt;
+
+#[derive(Default, Debug)]
+pub struct Markup {
+    text: String,
+}
+
+impl From<Markup> for String {
+    fn from(markup: Markup) -> Self {
+        markup.text
+    }
+}
+
+impl From<String> for Markup {
+    fn from(text: String) -> Self {
+        Markup { text }
+    }
+}
+
+impl fmt::Display for Markup {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.text, f)
+    }
+}
+
+impl Markup {
+    pub fn as_str(&self) -> &str {
+        self.text.as_str()
+    }
+    pub fn fenced_block(contents: &impl fmt::Display) -> Markup {
+        format!("```rust\n{}\n```", contents).into()
+    }
+}
diff --git a/crates/ide/src/matching_brace.rs b/crates/ide/src/matching_brace.rs
new file mode 100644
index 000000000..cb6abb0db
--- /dev/null
+++ b/crates/ide/src/matching_brace.rs
@@ -0,0 +1,73 @@
+use syntax::{
+    ast::{self, AstNode},
+    SourceFile, SyntaxKind, TextSize, T,
+};
+use test_utils::mark;
+
+// Feature: Matching Brace
+//
+// If the cursor is on any brace (`<>(){}[]||`) which is a part of a brace-pair,
+// moves cursor to the matching brace. It uses the actual parser to determine
+// braces, so it won't confuse generics with comparisons.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Find matching brace**
+// |===
+pub fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<TextSize> {
+    const BRACES: &[SyntaxKind] =
+        &[T!['{'], T!['}'], T!['['], T![']'], T!['('], T![')'], T![<], T![>], T![|], T![|]];
+    let (brace_token, brace_idx) = file
+        .syntax()
+        .token_at_offset(offset)
+        .filter_map(|node| {
+            let idx = BRACES.iter().position(|&brace| brace == node.kind())?;
+            Some((node, idx))
+        })
+        .next()?;
+    let parent = brace_token.parent();
+    if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
+        mark::hit!(pipes_not_braces);
+        return None;
+    }
+    let matching_kind = BRACES[brace_idx ^ 1];
+    let matching_node = parent
+        .children_with_tokens()
+        .filter_map(|it| it.into_token())
+        .find(|node| node.kind() == matching_kind && node != &brace_token)?;
+    Some(matching_node.text_range().start())
+}
+
+#[cfg(test)]
+mod tests {
+    use test_utils::{add_cursor, assert_eq_text, extract_offset};
+
+    use super::*;
+
+    #[test]
+    fn test_matching_brace() {
+        fn do_check(before: &str, after: &str) {
+            let (pos, before) = extract_offset(before);
+            let parse = SourceFile::parse(&before);
+            let new_pos = match matching_brace(&parse.tree(), pos) {
+                None => pos,
+                Some(pos) => pos,
+            };
+            let actual = add_cursor(&before, new_pos);
+            assert_eq_text!(after, &actual);
+        }
+
+        do_check("struct Foo { a: i32, }<|>", "struct Foo <|>{ a: i32, }");
+        do_check("fn main() { |x: i32|<|> x * 2;}", "fn main() { <|>|x: i32| x * 2;}");
+        do_check("fn main() { <|>|x: i32| x * 2;}", "fn main() { |x: i32<|>| x * 2;}");
+
+        {
+            mark::check!(pipes_not_braces);
+            do_check(
+                "fn main() { match 92 { 1 | 2 |<|> 3 => 92 } }",
+                "fn main() { match 92 { 1 | 2 |<|> 3 => 92 } }",
+            );
+        }
+    }
+}
diff --git a/crates/ide/src/mock_analysis.rs b/crates/ide/src/mock_analysis.rs
new file mode 100644
index 000000000..363e6d27e
--- /dev/null
+++ b/crates/ide/src/mock_analysis.rs
@@ -0,0 +1,176 @@
+//! FIXME: write short doc here
+use std::sync::Arc;
+
+use base_db::{CrateName, FileSet, SourceRoot, VfsPath};
+use cfg::CfgOptions;
+use test_utils::{
+    extract_annotations, extract_range_or_offset, Fixture, RangeOrOffset, CURSOR_MARKER,
+};
+
+use crate::{
+    Analysis, AnalysisChange, AnalysisHost, CrateGraph, Edition, FileId, FilePosition, FileRange,
+};
+
+/// Mock analysis is used in test to bootstrap an AnalysisHost/Analysis
+/// from a set of in-memory files.
+#[derive(Debug, Default)]
+pub struct MockAnalysis {
+    files: Vec<Fixture>,
+}
+
+impl MockAnalysis {
+    /// Creates `MockAnalysis` using a fixture data in the following format:
+    ///
+    /// ```not_rust
+    /// //- /main.rs
+    /// mod foo;
+    /// fn main() {}
+    ///
+    /// //- /foo.rs
+    /// struct Baz;
+    /// ```
+    pub fn with_files(ra_fixture: &str) -> MockAnalysis {
+        let (res, pos) = MockAnalysis::with_fixture(ra_fixture);
+        assert!(pos.is_none());
+        res
+    }
+
+    /// Same as `with_files`, but requires that a single file contains a `<|>` marker,
+    /// whose position is also returned.
+    pub fn with_files_and_position(fixture: &str) -> (MockAnalysis, FilePosition) {
+        let (res, position) = MockAnalysis::with_fixture(fixture);
+        let (file_id, range_or_offset) = position.expect("expected a marker (<|>)");
+        let offset = match range_or_offset {
+            RangeOrOffset::Range(_) => panic!(),
+            RangeOrOffset::Offset(it) => it,
+        };
+        (res, FilePosition { file_id, offset })
+    }
+
+    fn with_fixture(fixture: &str) -> (MockAnalysis, Option<(FileId, RangeOrOffset)>) {
+        let mut position = None;
+        let mut res = MockAnalysis::default();
+        for mut entry in Fixture::parse(fixture) {
+            if entry.text.contains(CURSOR_MARKER) {
+                assert!(position.is_none(), "only one marker (<|>) per fixture is allowed");
+                let (range_or_offset, text) = extract_range_or_offset(&entry.text);
+                entry.text = text;
+                let file_id = res.add_file_fixture(entry);
+                position = Some((file_id, range_or_offset));
+            } else {
+                res.add_file_fixture(entry);
+            }
+        }
+        (res, position)
+    }
+
+    fn add_file_fixture(&mut self, fixture: Fixture) -> FileId {
+        let file_id = FileId((self.files.len() + 1) as u32);
+        self.files.push(fixture);
+        file_id
+    }
+
+    pub fn id_of(&self, path: &str) -> FileId {
+        let (file_id, _) =
+            self.files().find(|(_, data)| path == data.path).expect("no file in this mock");
+        file_id
+    }
+    pub fn annotations(&self) -> Vec<(FileRange, String)> {
+        self.files()
+            .flat_map(|(file_id, fixture)| {
+                let annotations = extract_annotations(&fixture.text);
+                annotations
+                    .into_iter()
+                    .map(move |(range, data)| (FileRange { file_id, range }, data))
+            })
+            .collect()
+    }
+    pub fn files(&self) -> impl Iterator<Item = (FileId, &Fixture)> + '_ {
+        self.files.iter().enumerate().map(|(idx, fixture)| (FileId(idx as u32 + 1), fixture))
+    }
+    pub fn annotation(&self) -> (FileRange, String) {
+        let mut all = self.annotations();
+        assert_eq!(all.len(), 1);
+        all.pop().unwrap()
+    }
+    pub fn analysis_host(self) -> AnalysisHost {
+        let mut host = AnalysisHost::default();
+        let mut change = AnalysisChange::new();
+        let mut file_set = FileSet::default();
+        let mut crate_graph = CrateGraph::default();
+        let mut root_crate = None;
+        for (i, data) in self.files.into_iter().enumerate() {
+            let path = data.path;
+            assert!(path.starts_with('/'));
+
+            let mut cfg = CfgOptions::default();
+            data.cfg_atoms.iter().for_each(|it| cfg.insert_atom(it.into()));
+            data.cfg_key_values.iter().for_each(|(k, v)| cfg.insert_key_value(k.into(), v.into()));
+            let edition: Edition =
+                data.edition.and_then(|it| it.parse().ok()).unwrap_or(Edition::Edition2018);
+
+            let file_id = FileId(i as u32 + 1);
+            let env = data.env.into_iter().collect();
+            if path == "/lib.rs" || path == "/main.rs" {
+                root_crate = Some(crate_graph.add_crate_root(
+                    file_id,
+                    edition,
+                    None,
+                    cfg,
+                    env,
+                    Default::default(),
+                ));
+            } else if path.ends_with("/lib.rs") {
+                let base = &path[..path.len() - "/lib.rs".len()];
+                let crate_name = &base[base.rfind('/').unwrap() + '/'.len_utf8()..];
+                let other_crate = crate_graph.add_crate_root(
+                    file_id,
+                    edition,
+                    Some(crate_name.to_string()),
+                    cfg,
+                    env,
+                    Default::default(),
+                );
+                if let Some(root_crate) = root_crate {
+                    crate_graph
+                        .add_dep(root_crate, CrateName::new(crate_name).unwrap(), other_crate)
+                        .unwrap();
+                }
+            }
+            let path = VfsPath::new_virtual_path(path.to_string());
+            file_set.insert(file_id, path);
+            change.change_file(file_id, Some(Arc::new(data.text).to_owned()));
+        }
+        change.set_crate_graph(crate_graph);
+        change.set_roots(vec![SourceRoot::new_local(file_set)]);
+        host.apply_change(change);
+        host
+    }
+    pub fn analysis(self) -> Analysis {
+        self.analysis_host().analysis()
+    }
+}
+
+/// Creates analysis from a multi-file fixture, returns positions marked with <|>.
+pub fn analysis_and_position(ra_fixture: &str) -> (Analysis, FilePosition) {
+    let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+    (mock.analysis(), position)
+}
+
+/// Creates analysis for a single file.
+pub fn single_file(ra_fixture: &str) -> (Analysis, FileId) {
+    let mock = MockAnalysis::with_files(ra_fixture);
+    let file_id = mock.id_of("/main.rs");
+    (mock.analysis(), file_id)
+}
+
+/// Creates analysis for a single file, returns range marked with a pair of <|>.
+pub fn analysis_and_range(ra_fixture: &str) -> (Analysis, FileRange) {
+    let (res, position) = MockAnalysis::with_fixture(ra_fixture);
+    let (file_id, range_or_offset) = position.expect("expected a marker (<|>)");
+    let range = match range_or_offset {
+        RangeOrOffset::Range(it) => it,
+        RangeOrOffset::Offset(_) => panic!(),
+    };
+    (res.analysis(), FileRange { file_id, range })
+}
diff --git a/crates/ide/src/parent_module.rs b/crates/ide/src/parent_module.rs
new file mode 100644
index 000000000..59ed2967c
--- /dev/null
+++ b/crates/ide/src/parent_module.rs
@@ -0,0 +1,155 @@
+use base_db::{CrateId, FileId, FilePosition};
+use hir::Semantics;
+use ide_db::RootDatabase;
+use syntax::{
+    algo::find_node_at_offset,
+    ast::{self, AstNode},
+};
+use test_utils::mark;
+
+use crate::NavigationTarget;
+
+// Feature: Parent Module
+//
+// Navigates to the parent module of the current module.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Locate parent module**
+// |===
+
+/// This returns `Vec` because a module may be included from several places. We
+/// don't handle this case yet though, so the Vec has length at most one.
+pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<NavigationTarget> {
+    let sema = Semantics::new(db);
+    let source_file = sema.parse(position.file_id);
+
+    let mut module = find_node_at_offset::<ast::Module>(source_file.syntax(), position.offset);
+
+    // If cursor is literally on `mod foo`, go to the grandpa.
+    if let Some(m) = &module {
+        if !m
+            .item_list()
+            .map_or(false, |it| it.syntax().text_range().contains_inclusive(position.offset))
+        {
+            mark::hit!(test_resolve_parent_module_on_module_decl);
+            module = m.syntax().ancestors().skip(1).find_map(ast::Module::cast);
+        }
+    }
+
+    let module = match module {
+        Some(module) => sema.to_def(&module),
+        None => sema.to_module_def(position.file_id),
+    };
+    let module = match module {
+        None => return Vec::new(),
+        Some(it) => it,
+    };
+    let nav = NavigationTarget::from_module_to_decl(db, module);
+    vec![nav]
+}
+
+/// Returns `Vec` for the same reason as `parent_module`
+pub(crate) fn crate_for(db: &RootDatabase, file_id: FileId) -> Vec<CrateId> {
+    let sema = Semantics::new(db);
+    let module = match sema.to_module_def(file_id) {
+        Some(it) => it,
+        None => return Vec::new(),
+    };
+    let krate = module.krate();
+    vec![krate.into()]
+}
+
+#[cfg(test)]
+mod tests {
+    use base_db::Env;
+    use cfg::CfgOptions;
+    use test_utils::mark;
+
+    use crate::{
+        mock_analysis::{analysis_and_position, MockAnalysis},
+        AnalysisChange, CrateGraph,
+        Edition::Edition2018,
+    };
+
+    #[test]
+    fn test_resolve_parent_module() {
+        let (analysis, pos) = analysis_and_position(
+            "
+            //- /lib.rs
+            mod foo;
+            //- /foo.rs
+            <|>// empty
+            ",
+        );
+        let nav = analysis.parent_module(pos).unwrap().pop().unwrap();
+        nav.assert_match("foo MODULE FileId(1) 0..8");
+    }
+
+    #[test]
+    fn test_resolve_parent_module_on_module_decl() {
+        mark::check!(test_resolve_parent_module_on_module_decl);
+        let (analysis, pos) = analysis_and_position(
+            "
+            //- /lib.rs
+            mod foo;
+
+            //- /foo.rs
+            mod <|>bar;
+
+            //- /foo/bar.rs
+            // empty
+            ",
+        );
+        let nav = analysis.parent_module(pos).unwrap().pop().unwrap();
+        nav.assert_match("foo MODULE FileId(1) 0..8");
+    }
+
+    #[test]
+    fn test_resolve_parent_module_for_inline() {
+        let (analysis, pos) = analysis_and_position(
+            "
+            //- /lib.rs
+            mod foo {
+                mod bar {
+                    mod baz { <|> }
+                }
+            }
+            ",
+        );
+        let nav = analysis.parent_module(pos).unwrap().pop().unwrap();
+        nav.assert_match("baz MODULE FileId(1) 32..44");
+    }
+
+    #[test]
+    fn test_resolve_crate_root() {
+        let mock = MockAnalysis::with_files(
+            r#"
+//- /bar.rs
+mod foo;
+//- /foo.rs
+// empty
+"#,
+        );
+        let root_file = mock.id_of("/bar.rs");
+        let mod_file = mock.id_of("/foo.rs");
+        let mut host = mock.analysis_host();
+        assert!(host.analysis().crate_for(mod_file).unwrap().is_empty());
+
+        let mut crate_graph = CrateGraph::default();
+        let crate_id = crate_graph.add_crate_root(
+            root_file,
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let mut change = AnalysisChange::new();
+        change.set_crate_graph(crate_graph);
+        host.apply_change(change);
+
+        assert_eq!(host.analysis().crate_for(mod_file).unwrap(), vec![crate_id]);
+    }
+}
diff --git a/crates/ide/src/prime_caches.rs b/crates/ide/src/prime_caches.rs
new file mode 100644
index 000000000..c5ab5a1d8
--- /dev/null
+++ b/crates/ide/src/prime_caches.rs
@@ -0,0 +1,12 @@
+//! rust-analyzer is lazy and doesn't not compute anything unless asked. This
+//! sometimes is counter productive when, for example, the first goto definition
+//! request takes longer to compute. This modules implemented prepopulating of
+//! various caches, it's not really advanced at the moment.
+
+use crate::{FileId, RootDatabase};
+
+pub(crate) fn prime_caches(db: &RootDatabase, files: Vec<FileId>) {
+    for file in files {
+        let _ = crate::syntax_highlighting::highlight(db, file, None, false);
+    }
+}
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
new file mode 100644
index 000000000..0a76ec6b4
--- /dev/null
+++ b/crates/ide/src/references.rs
@@ -0,0 +1,694 @@
+//! This module implements a reference search.
+//! First, the element at the cursor position must be either an `ast::Name`
+//! or `ast::NameRef`. If it's a `ast::NameRef`, at the classification step we
+//! try to resolve the direct tree parent of this element, otherwise we
+//! already have a definition and just need to get its HIR together with
+//! some information that is needed for futher steps of searching.
+//! After that, we collect files that might contain references and look
+//! for text occurrences of the identifier. If there's an `ast::NameRef`
+//! at the index that the match starts at and its tree parent is
+//! resolved to the search element definition, we get a reference.
+
+mod rename;
+
+use hir::Semantics;
+use ide_db::{
+    defs::{classify_name, classify_name_ref, Definition},
+    search::SearchScope,
+    RootDatabase,
+};
+use syntax::{
+    algo::find_node_at_offset,
+    ast::{self, NameOwner},
+    AstNode, SyntaxKind, SyntaxNode, TextRange, TokenAtOffset,
+};
+
+use crate::{display::TryToNav, FilePosition, FileRange, NavigationTarget, RangeInfo};
+
+pub(crate) use self::rename::rename;
+
+pub use ide_db::search::{Reference, ReferenceAccess, ReferenceKind};
+
+#[derive(Debug, Clone)]
+pub struct ReferenceSearchResult {
+    declaration: Declaration,
+    references: Vec<Reference>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Declaration {
+    pub nav: NavigationTarget,
+    pub kind: ReferenceKind,
+    pub access: Option<ReferenceAccess>,
+}
+
+impl ReferenceSearchResult {
+    pub fn declaration(&self) -> &Declaration {
+        &self.declaration
+    }
+
+    pub fn decl_target(&self) -> &NavigationTarget {
+        &self.declaration.nav
+    }
+
+    pub fn references(&self) -> &[Reference] {
+        &self.references
+    }
+
+    /// Total number of references
+    /// At least 1 since all valid references should
+    /// Have a declaration
+    pub fn len(&self) -> usize {
+        self.references.len() + 1
+    }
+}
+
+// allow turning ReferenceSearchResult into an iterator
+// over References
+impl IntoIterator for ReferenceSearchResult {
+    type Item = Reference;
+    type IntoIter = std::vec::IntoIter<Reference>;
+
+    fn into_iter(mut self) -> Self::IntoIter {
+        let mut v = Vec::with_capacity(self.len());
+        v.push(Reference {
+            file_range: FileRange {
+                file_id: self.declaration.nav.file_id,
+                range: self.declaration.nav.focus_or_full_range(),
+            },
+            kind: self.declaration.kind,
+            access: self.declaration.access,
+        });
+        v.append(&mut self.references);
+        v.into_iter()
+    }
+}
+
+pub(crate) fn find_all_refs(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    search_scope: Option<SearchScope>,
+) -> Option<RangeInfo<ReferenceSearchResult>> {
+    let _p = profile::span("find_all_refs");
+    let syntax = sema.parse(position.file_id).syntax().clone();
+
+    let (opt_name, search_kind) = if let Some(name) =
+        get_struct_def_name_for_struct_literal_search(&sema, &syntax, position)
+    {
+        (Some(name), ReferenceKind::StructLiteral)
+    } else {
+        (
+            sema.find_node_at_offset_with_descend::<ast::Name>(&syntax, position.offset),
+            ReferenceKind::Other,
+        )
+    };
+
+    let RangeInfo { range, info: def } = find_name(&sema, &syntax, position, opt_name)?;
+
+    let references = def
+        .find_usages(sema, search_scope)
+        .into_iter()
+        .filter(|r| search_kind == ReferenceKind::Other || search_kind == r.kind)
+        .collect();
+
+    let decl_range = def.try_to_nav(sema.db)?.focus_or_full_range();
+
+    let declaration = Declaration {
+        nav: def.try_to_nav(sema.db)?,
+        kind: ReferenceKind::Other,
+        access: decl_access(&def, &syntax, decl_range),
+    };
+
+    Some(RangeInfo::new(range, ReferenceSearchResult { declaration, references }))
+}
+
+fn find_name(
+    sema: &Semantics<RootDatabase>,
+    syntax: &SyntaxNode,
+    position: FilePosition,
+    opt_name: Option<ast::Name>,
+) -> Option<RangeInfo<Definition>> {
+    if let Some(name) = opt_name {
+        let def = classify_name(sema, &name)?.definition(sema.db);
+        let range = name.syntax().text_range();
+        return Some(RangeInfo::new(range, def));
+    }
+    let name_ref =
+        sema.find_node_at_offset_with_descend::<ast::NameRef>(&syntax, position.offset)?;
+    let def = classify_name_ref(sema, &name_ref)?.definition(sema.db);
+    let range = name_ref.syntax().text_range();
+    Some(RangeInfo::new(range, def))
+}
+
+fn decl_access(def: &Definition, syntax: &SyntaxNode, range: TextRange) -> Option<ReferenceAccess> {
+    match def {
+        Definition::Local(_) | Definition::Field(_) => {}
+        _ => return None,
+    };
+
+    let stmt = find_node_at_offset::<ast::LetStmt>(syntax, range.start())?;
+    if stmt.initializer().is_some() {
+        let pat = stmt.pat()?;
+        if let ast::Pat::IdentPat(it) = pat {
+            if it.mut_token().is_some() {
+                return Some(ReferenceAccess::Write);
+            }
+        }
+    }
+
+    None
+}
+
+fn get_struct_def_name_for_struct_literal_search(
+    sema: &Semantics<RootDatabase>,
+    syntax: &SyntaxNode,
+    position: FilePosition,
+) -> Option<ast::Name> {
+    if let TokenAtOffset::Between(ref left, ref right) = syntax.token_at_offset(position.offset) {
+        if right.kind() != SyntaxKind::L_CURLY && right.kind() != SyntaxKind::L_PAREN {
+            return None;
+        }
+        if let Some(name) =
+            sema.find_node_at_offset_with_descend::<ast::Name>(&syntax, left.text_range().start())
+        {
+            return name.syntax().ancestors().find_map(ast::Struct::cast).and_then(|l| l.name());
+        }
+        if sema
+            .find_node_at_offset_with_descend::<ast::GenericParamList>(
+                &syntax,
+                left.text_range().start(),
+            )
+            .is_some()
+        {
+            return left.ancestors().find_map(ast::Struct::cast).and_then(|l| l.name());
+        }
+    }
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{
+        mock_analysis::{analysis_and_position, MockAnalysis},
+        Declaration, Reference, ReferenceSearchResult, SearchScope,
+    };
+
+    #[test]
+    fn test_struct_literal_after_space() {
+        let refs = get_all_refs(
+            r#"
+struct Foo <|>{
+    a: i32,
+}
+impl Foo {
+    fn f() -> i32 { 42 }
+}
+fn main() {
+    let f: Foo;
+    f = Foo {a: Foo::f()};
+}
+"#,
+        );
+        check_result(
+            refs,
+            "Foo STRUCT FileId(1) 0..26 7..10 Other",
+            &["FileId(1) 101..104 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_struct_literal_before_space() {
+        let refs = get_all_refs(
+            r#"
+struct Foo<|> {}
+    fn main() {
+    let f: Foo;
+    f = Foo {};
+}
+"#,
+        );
+        check_result(
+            refs,
+            "Foo STRUCT FileId(1) 0..13 7..10 Other",
+            &["FileId(1) 41..44 Other", "FileId(1) 54..57 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_struct_literal_with_generic_type() {
+        let refs = get_all_refs(
+            r#"
+struct Foo<T> <|>{}
+    fn main() {
+    let f: Foo::<i32>;
+    f = Foo {};
+}
+"#,
+        );
+        check_result(
+            refs,
+            "Foo STRUCT FileId(1) 0..16 7..10 Other",
+            &["FileId(1) 64..67 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_struct_literal_for_tuple() {
+        let refs = get_all_refs(
+            r#"
+struct Foo<|>(i32);
+
+fn main() {
+    let f: Foo;
+    f = Foo(1);
+}
+"#,
+        );
+        check_result(
+            refs,
+            "Foo STRUCT FileId(1) 0..16 7..10 Other",
+            &["FileId(1) 54..57 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_for_local() {
+        let refs = get_all_refs(
+            r#"
+fn main() {
+    let mut i = 1;
+    let j = 1;
+    i = i<|> + j;
+
+    {
+        i = 0;
+    }
+
+    i = 5;
+}"#,
+        );
+        check_result(
+            refs,
+            "i IDENT_PAT FileId(1) 24..25 Other Write",
+            &[
+                "FileId(1) 50..51 Other Write",
+                "FileId(1) 54..55 Other Read",
+                "FileId(1) 76..77 Other Write",
+                "FileId(1) 94..95 Other Write",
+            ],
+        );
+    }
+
+    #[test]
+    fn search_filters_by_range() {
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let spam<|> = 92;
+    spam + spam
+}
+fn bar() {
+    let spam = 92;
+    spam + spam
+}
+"#,
+        );
+        check_result(
+            refs,
+            "spam IDENT_PAT FileId(1) 19..23 Other",
+            &["FileId(1) 34..38 Other Read", "FileId(1) 41..45 Other Read"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_for_param_inside() {
+        let refs = get_all_refs(
+            r#"
+fn foo(i : u32) -> u32 {
+    i<|>
+}
+"#,
+        );
+        check_result(refs, "i IDENT_PAT FileId(1) 7..8 Other", &["FileId(1) 29..30 Other Read"]);
+    }
+
+    #[test]
+    fn test_find_all_refs_for_fn_param() {
+        let refs = get_all_refs(
+            r#"
+fn foo(i<|> : u32) -> u32 {
+    i
+}
+"#,
+        );
+        check_result(refs, "i IDENT_PAT FileId(1) 7..8 Other", &["FileId(1) 29..30 Other Read"]);
+    }
+
+    #[test]
+    fn test_find_all_refs_field_name() {
+        let refs = get_all_refs(
+            r#"
+//- /lib.rs
+struct Foo {
+    pub spam<|>: u32,
+}
+
+fn main(s: Foo) {
+    let f = s.spam;
+}
+"#,
+        );
+        check_result(
+            refs,
+            "spam RECORD_FIELD FileId(1) 17..30 21..25 Other",
+            &["FileId(1) 67..71 Other Read"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_impl_item_name() {
+        let refs = get_all_refs(
+            r#"
+struct Foo;
+impl Foo {
+    fn f<|>(&self) {  }
+}
+"#,
+        );
+        check_result(refs, "f FN FileId(1) 27..43 30..31 Other", &[]);
+    }
+
+    #[test]
+    fn test_find_all_refs_enum_var_name() {
+        let refs = get_all_refs(
+            r#"
+enum Foo {
+    A,
+    B<|>,
+    C,
+}
+"#,
+        );
+        check_result(refs, "B VARIANT FileId(1) 22..23 22..23 Other", &[]);
+    }
+
+    #[test]
+    fn test_find_all_refs_two_modules() {
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+pub mod foo;
+pub mod bar;
+
+fn f() {
+    let i = foo::Foo { n: 5 };
+}
+
+//- /foo.rs
+use crate::bar;
+
+pub struct Foo {
+    pub n: u32,
+}
+
+fn f() {
+    let i = bar::Bar { n: 5 };
+}
+
+//- /bar.rs
+use crate::foo;
+
+pub struct Bar {
+    pub n: u32,
+}
+
+fn f() {
+    let i = foo::Foo<|> { n: 5 };
+}
+"#,
+        );
+        let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
+        check_result(
+            refs,
+            "Foo STRUCT FileId(2) 17..51 28..31 Other",
+            &["FileId(1) 53..56 StructLiteral", "FileId(3) 79..82 StructLiteral"],
+        );
+    }
+
+    // `mod foo;` is not in the results because `foo` is an `ast::Name`.
+    // So, there are two references: the first one is a definition of the `foo` module,
+    // which is the whole `foo.rs`, and the second one is in `use foo::Foo`.
+    #[test]
+    fn test_find_all_refs_decl_module() {
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+mod foo<|>;
+
+use foo::Foo;
+
+fn f() {
+    let i = Foo { n: 5 };
+}
+
+//- /foo.rs
+pub struct Foo {
+    pub n: u32,
+}
+"#,
+        );
+        let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
+        check_result(refs, "foo SOURCE_FILE FileId(2) 0..35 Other", &["FileId(1) 14..17 Other"]);
+    }
+
+    #[test]
+    fn test_find_all_refs_super_mod_vis() {
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+mod foo;
+
+//- /foo.rs
+mod some;
+use some::Foo;
+
+fn f() {
+    let i = Foo { n: 5 };
+}
+
+//- /foo/some.rs
+pub(super) struct Foo<|> {
+    pub n: u32,
+}
+"#,
+        );
+        let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
+        check_result(
+            refs,
+            "Foo STRUCT FileId(3) 0..41 18..21 Other",
+            &["FileId(2) 20..23 Other", "FileId(2) 47..50 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_with_scope() {
+        let code = r#"
+            //- /lib.rs
+            mod foo;
+            mod bar;
+
+            pub fn quux<|>() {}
+
+            //- /foo.rs
+            fn f() { super::quux(); }
+
+            //- /bar.rs
+            fn f() { super::quux(); }
+        "#;
+
+        let (mock, pos) = MockAnalysis::with_files_and_position(code);
+        let bar = mock.id_of("/bar.rs");
+        let analysis = mock.analysis();
+
+        let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
+        check_result(
+            refs,
+            "quux FN FileId(1) 19..35 26..30 Other",
+            &["FileId(2) 16..20 StructLiteral", "FileId(3) 16..20 StructLiteral"],
+        );
+
+        let refs =
+            analysis.find_all_refs(pos, Some(SearchScope::single_file(bar))).unwrap().unwrap();
+        check_result(
+            refs,
+            "quux FN FileId(1) 19..35 26..30 Other",
+            &["FileId(3) 16..20 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_macro_def() {
+        let refs = get_all_refs(
+            r#"
+#[macro_export]
+macro_rules! m1<|> { () => (()) }
+
+fn foo() {
+    m1();
+    m1();
+}
+"#,
+        );
+        check_result(
+            refs,
+            "m1 MACRO_CALL FileId(1) 0..46 29..31 Other",
+            &["FileId(1) 63..65 StructLiteral", "FileId(1) 73..75 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_basic_highlight_read_write() {
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let mut i<|> = 0;
+    i = i + 1;
+}
+"#,
+        );
+        check_result(
+            refs,
+            "i IDENT_PAT FileId(1) 23..24 Other Write",
+            &["FileId(1) 34..35 Other Write", "FileId(1) 38..39 Other Read"],
+        );
+    }
+
+    #[test]
+    fn test_basic_highlight_field_read_write() {
+        let refs = get_all_refs(
+            r#"
+struct S {
+    f: u32,
+}
+
+fn foo() {
+    let mut s = S{f: 0};
+    s.f<|> = 0;
+}
+"#,
+        );
+        check_result(
+            refs,
+            "f RECORD_FIELD FileId(1) 15..21 15..16 Other",
+            &["FileId(1) 55..56 Other Read", "FileId(1) 68..69 Other Write"],
+        );
+    }
+
+    #[test]
+    fn test_basic_highlight_decl_no_write() {
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let i<|>;
+    i = 1;
+}
+"#,
+        );
+        check_result(refs, "i IDENT_PAT FileId(1) 19..20 Other", &["FileId(1) 26..27 Other Write"]);
+    }
+
+    #[test]
+    fn test_find_struct_function_refs_outside_module() {
+        let refs = get_all_refs(
+            r#"
+mod foo {
+    pub struct Foo;
+
+    impl Foo {
+        pub fn new<|>() -> Foo {
+            Foo
+        }
+    }
+}
+
+fn main() {
+    let _f = foo::Foo::new();
+}
+"#,
+        );
+        check_result(
+            refs,
+            "new FN FileId(1) 54..101 61..64 Other",
+            &["FileId(1) 146..149 StructLiteral"],
+        );
+    }
+
+    #[test]
+    fn test_find_all_refs_nested_module() {
+        let code = r#"
+            //- /lib.rs
+            mod foo {
+                mod bar;
+            }
+
+            fn f<|>() {}
+
+            //- /foo/bar.rs
+            use crate::f;
+
+            fn g() {
+                f();
+            }
+        "#;
+
+        let (analysis, pos) = analysis_and_position(code);
+        let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
+        check_result(
+            refs,
+            "f FN FileId(1) 26..35 29..30 Other",
+            &["FileId(2) 11..12 Other", "FileId(2) 28..29 StructLiteral"],
+        );
+    }
+
+    fn get_all_refs(ra_fixture: &str) -> ReferenceSearchResult {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        analysis.find_all_refs(position, None).unwrap().unwrap()
+    }
+
+    fn check_result(res: ReferenceSearchResult, expected_decl: &str, expected_refs: &[&str]) {
+        res.declaration().assert_match(expected_decl);
+        assert_eq!(res.references.len(), expected_refs.len());
+        res.references()
+            .iter()
+            .enumerate()
+            .for_each(|(i, r)| ref_assert_match(r, expected_refs[i]));
+    }
+
+    impl Declaration {
+        fn debug_render(&self) -> String {
+            let mut s = format!("{} {:?}", self.nav.debug_render(), self.kind);
+            if let Some(access) = self.access {
+                s.push_str(&format!(" {:?}", access));
+            }
+            s
+        }
+
+        fn assert_match(&self, expected: &str) {
+            let actual = self.debug_render();
+            test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+        }
+    }
+
+    fn ref_debug_render(r: &Reference) -> String {
+        let mut s = format!("{:?} {:?} {:?}", r.file_range.file_id, r.file_range.range, r.kind);
+        if let Some(access) = r.access {
+            s.push_str(&format!(" {:?}", access));
+        }
+        s
+    }
+
+    fn ref_assert_match(r: &Reference, expected: &str) {
+        let actual = ref_debug_render(r);
+        test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+    }
+}
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
new file mode 100644
index 000000000..d73dc9cd0
--- /dev/null
+++ b/crates/ide/src/references/rename.rs
@@ -0,0 +1,1010 @@
+//! FIXME: write short doc here
+
+use base_db::SourceDatabaseExt;
+use hir::{Module, ModuleDef, ModuleSource, Semantics};
+use ide_db::{
+    defs::{classify_name, classify_name_ref, Definition, NameClass, NameRefClass},
+    RootDatabase,
+};
+use std::convert::TryInto;
+use syntax::{
+    algo::find_node_at_offset,
+    ast::{self, NameOwner},
+    lex_single_valid_syntax_kind, match_ast, AstNode, SyntaxKind, SyntaxNode, SyntaxToken,
+};
+use test_utils::mark;
+use text_edit::TextEdit;
+
+use crate::{
+    references::find_all_refs, FilePosition, FileSystemEdit, RangeInfo, Reference, ReferenceKind,
+    SourceChange, SourceFileEdit, TextRange, TextSize,
+};
+
+pub(crate) fn rename(
+    db: &RootDatabase,
+    position: FilePosition,
+    new_name: &str,
+) -> Option<RangeInfo<SourceChange>> {
+    let sema = Semantics::new(db);
+
+    match lex_single_valid_syntax_kind(new_name)? {
+        SyntaxKind::IDENT | SyntaxKind::UNDERSCORE => (),
+        SyntaxKind::SELF_KW => return rename_to_self(&sema, position),
+        _ => return None,
+    }
+
+    let source_file = sema.parse(position.file_id);
+    let syntax = source_file.syntax();
+    if let Some(module) = find_module_at_offset(&sema, position, syntax) {
+        rename_mod(&sema, position, module, new_name)
+    } else if let Some(self_token) =
+        syntax.token_at_offset(position.offset).find(|t| t.kind() == SyntaxKind::SELF_KW)
+    {
+        rename_self_to_param(&sema, position, self_token, new_name)
+    } else {
+        rename_reference(&sema, position, new_name)
+    }
+}
+
+fn find_module_at_offset(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    syntax: &SyntaxNode,
+) -> Option<Module> {
+    let ident = syntax.token_at_offset(position.offset).find(|t| t.kind() == SyntaxKind::IDENT)?;
+
+    let module = match_ast! {
+        match (ident.parent()) {
+            ast::NameRef(name_ref) => {
+                match classify_name_ref(sema, &name_ref)? {
+                    NameRefClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+                    _ => return None,
+                }
+            },
+            ast::Name(name) => {
+                match classify_name(&sema, &name)? {
+                    NameClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+                    _ => return None,
+                }
+            },
+            _ => return None,
+        }
+    };
+
+    Some(module)
+}
+
+fn source_edit_from_reference(reference: Reference, new_name: &str) -> SourceFileEdit {
+    let mut replacement_text = String::new();
+    let file_id = reference.file_range.file_id;
+    let range = match reference.kind {
+        ReferenceKind::FieldShorthandForField => {
+            mark::hit!(test_rename_struct_field_for_shorthand);
+            replacement_text.push_str(new_name);
+            replacement_text.push_str(": ");
+            TextRange::new(reference.file_range.range.start(), reference.file_range.range.start())
+        }
+        ReferenceKind::FieldShorthandForLocal => {
+            mark::hit!(test_rename_local_for_field_shorthand);
+            replacement_text.push_str(": ");
+            replacement_text.push_str(new_name);
+            TextRange::new(reference.file_range.range.end(), reference.file_range.range.end())
+        }
+        _ => {
+            replacement_text.push_str(new_name);
+            reference.file_range.range
+        }
+    };
+    SourceFileEdit { file_id, edit: TextEdit::replace(range, replacement_text) }
+}
+
+fn rename_mod(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    module: Module,
+    new_name: &str,
+) -> Option<RangeInfo<SourceChange>> {
+    let mut source_file_edits = Vec::new();
+    let mut file_system_edits = Vec::new();
+
+    let src = module.definition_source(sema.db);
+    let file_id = src.file_id.original_file(sema.db);
+    match src.value {
+        ModuleSource::SourceFile(..) => {
+            // mod is defined in path/to/dir/mod.rs
+            let dst = if module.is_mod_rs(sema.db) {
+                format!("../{}/mod.rs", new_name)
+            } else {
+                format!("{}.rs", new_name)
+            };
+            let move_file = FileSystemEdit::MoveFile { src: file_id, anchor: file_id, dst };
+            file_system_edits.push(move_file);
+        }
+        ModuleSource::Module(..) => {}
+    }
+
+    if let Some(src) = module.declaration_source(sema.db) {
+        let file_id = src.file_id.original_file(sema.db);
+        let name = src.value.name()?;
+        let edit = SourceFileEdit {
+            file_id,
+            edit: TextEdit::replace(name.syntax().text_range(), new_name.into()),
+        };
+        source_file_edits.push(edit);
+    }
+
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+    let ref_edits = refs
+        .references
+        .into_iter()
+        .map(|reference| source_edit_from_reference(reference, new_name));
+    source_file_edits.extend(ref_edits);
+
+    Some(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
+}
+
+fn rename_to_self(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+) -> Option<RangeInfo<SourceChange>> {
+    let source_file = sema.parse(position.file_id);
+    let syn = source_file.syntax();
+
+    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)?;
+    let params = fn_def.param_list()?;
+    if params.self_param().is_some() {
+        return None; // method already has self param
+    }
+    let first_param = params.params().next()?;
+    let mutable = match first_param.ty() {
+        Some(ast::Type::RefType(rt)) => rt.mut_token().is_some(),
+        _ => return None, // not renaming other types
+    };
+
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+
+    let param_range = first_param.syntax().text_range();
+    let (param_ref, usages): (Vec<Reference>, Vec<Reference>) = refs
+        .into_iter()
+        .partition(|reference| param_range.intersect(reference.file_range.range).is_some());
+
+    if param_ref.is_empty() {
+        return None;
+    }
+
+    let mut edits = usages
+        .into_iter()
+        .map(|reference| source_edit_from_reference(reference, "self"))
+        .collect::<Vec<_>>();
+
+    edits.push(SourceFileEdit {
+        file_id: position.file_id,
+        edit: TextEdit::replace(
+            param_range,
+            String::from(if mutable { "&mut self" } else { "&self" }),
+        ),
+    });
+
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
+}
+
+fn text_edit_from_self_param(
+    syn: &SyntaxNode,
+    self_param: &ast::SelfParam,
+    new_name: &str,
+) -> Option<TextEdit> {
+    fn target_type_name(impl_def: &ast::Impl) -> Option<String> {
+        if let Some(ast::Type::PathType(p)) = impl_def.self_ty() {
+            return Some(p.path()?.segment()?.name_ref()?.text().to_string());
+        }
+        None
+    }
+
+    let impl_def = find_node_at_offset::<ast::Impl>(syn, self_param.syntax().text_range().start())?;
+    let type_name = target_type_name(&impl_def)?;
+
+    let mut replacement_text = String::from(new_name);
+    replacement_text.push_str(": ");
+    replacement_text.push_str(self_param.mut_token().map_or("&", |_| "&mut "));
+    replacement_text.push_str(type_name.as_str());
+
+    Some(TextEdit::replace(self_param.syntax().text_range(), replacement_text))
+}
+
+fn rename_self_to_param(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    self_token: SyntaxToken,
+    new_name: &str,
+) -> Option<RangeInfo<SourceChange>> {
+    let source_file = sema.parse(position.file_id);
+    let syn = source_file.syntax();
+
+    let text = sema.db.file_text(position.file_id);
+    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)?;
+    let search_range = fn_def.syntax().text_range();
+
+    let mut edits: Vec<SourceFileEdit> = vec![];
+
+    for (idx, _) in text.match_indices("self") {
+        let offset: TextSize = idx.try_into().unwrap();
+        if !search_range.contains_inclusive(offset) {
+            continue;
+        }
+        if let Some(ref usage) =
+            syn.token_at_offset(offset).find(|t| t.kind() == SyntaxKind::SELF_KW)
+        {
+            let edit = if let Some(ref self_param) = ast::SelfParam::cast(usage.parent()) {
+                text_edit_from_self_param(syn, self_param, new_name)?
+            } else {
+                TextEdit::replace(usage.text_range(), String::from(new_name))
+            };
+            edits.push(SourceFileEdit { file_id: position.file_id, edit });
+        }
+    }
+
+    let range = ast::SelfParam::cast(self_token.parent())
+        .map_or(self_token.text_range(), |p| p.syntax().text_range());
+
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
+}
+
+fn rename_reference(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    new_name: &str,
+) -> Option<RangeInfo<SourceChange>> {
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+
+    let edit = refs
+        .into_iter()
+        .map(|reference| source_edit_from_reference(reference, new_name))
+        .collect::<Vec<_>>();
+
+    if edit.is_empty() {
+        return None;
+    }
+
+    Some(RangeInfo::new(range, SourceChange::from(edit)))
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use stdx::trim_indent;
+    use test_utils::{assert_eq_text, mark};
+    use text_edit::TextEdit;
+
+    use crate::{mock_analysis::analysis_and_position, FileId};
+
+    fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let (analysis, position) = analysis_and_position(ra_fixture_before);
+        let source_change = analysis.rename(position, new_name).unwrap();
+        let mut text_edit_builder = TextEdit::builder();
+        let mut file_id: Option<FileId> = None;
+        if let Some(change) = source_change {
+            for edit in change.info.source_file_edits {
+                file_id = Some(edit.file_id);
+                for indel in edit.edit.into_iter() {
+                    text_edit_builder.replace(indel.delete, indel.insert);
+                }
+            }
+        }
+        let mut result = analysis.file_text(file_id.unwrap()).unwrap().to_string();
+        text_edit_builder.finish().apply(&mut result);
+        assert_eq_text!(ra_fixture_after, &*result);
+    }
+
+    fn check_expect(new_name: &str, ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let source_change = analysis.rename(position, new_name).unwrap().unwrap();
+        expect.assert_debug_eq(&source_change)
+    }
+
+    #[test]
+    fn test_rename_to_underscore() {
+        check("_", r#"fn main() { let i<|> = 1; }"#, r#"fn main() { let _ = 1; }"#);
+    }
+
+    #[test]
+    fn test_rename_to_raw_identifier() {
+        check("r#fn", r#"fn main() { let i<|> = 1; }"#, r#"fn main() { let r#fn = 1; }"#);
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier() {
+        let (analysis, position) = analysis_and_position(r#"fn main() { let i<|> = 1; }"#);
+        let new_name = "invalid!";
+        let source_change = analysis.rename(position, new_name).unwrap();
+        assert!(source_change.is_none());
+    }
+
+    #[test]
+    fn test_rename_for_local() {
+        check(
+            "k",
+            r#"
+fn main() {
+    let mut i = 1;
+    let j = 1;
+    i = i<|> + j;
+
+    { i = 0; }
+
+    i = 5;
+}
+"#,
+            r#"
+fn main() {
+    let mut k = 1;
+    let j = 1;
+    k = k + j;
+
+    { k = 0; }
+
+    k = 5;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_args() {
+        check(
+            "b",
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a<|> = "test";
+    foo!(a);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_args_rev() {
+        check(
+            "b",
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a = "test";
+    foo!(a<|>);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_define_fn() {
+        check(
+            "bar",
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(foo);
+fn main() {
+    fo<|>o();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_define_fn_rev() {
+        check(
+            "bar",
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(fo<|>o);
+fn main() {
+    foo();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_param_inside() {
+        check("j", r#"fn foo(i : u32) -> u32 { i<|> }"#, r#"fn foo(j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_refs_for_fn_param() {
+        check("j", r#"fn foo(i<|> : u32) -> u32 { i }"#, r#"fn foo(j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_for_mut_param() {
+        check("j", r#"fn foo(mut i<|> : u32) -> u32 { i }"#, r#"fn foo(mut j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_struct_field() {
+        check(
+            "j",
+            r#"
+struct Foo { i<|>: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i: i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_struct_field_for_shorthand() {
+        mark::check!(test_rename_struct_field_for_shorthand);
+        check(
+            "j",
+            r#"
+struct Foo { i<|>: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_local_for_field_shorthand() {
+        mark::check!(test_rename_local_for_field_shorthand);
+        check(
+            "j",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn new(i<|>: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn new(j: i32) -> Self {
+        Self { i: j }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_field_shorthand_correct_struct() {
+        check(
+            "j",
+            r#"
+struct Foo { i<|>: i32 }
+struct Bar { i: i32 }
+
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+struct Bar { i: i32 }
+
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_shadow_local_for_struct_shorthand() {
+        check(
+            "j",
+            r#"
+struct Foo { i: i32 }
+
+fn baz(i<|>: i32) -> Self {
+     let x = Foo { i };
+     {
+         let i = 0;
+         Foo { i }
+     }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+fn baz(j: i32) -> Self {
+     let x = Foo { i: j };
+     {
+         let i = 0;
+         Foo { i }
+     }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_mod() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+
+//- /bar.rs
+mod foo<|>;
+
+//- /bar/foo.rs
+// empty
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 4..7,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    2,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 4..7,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    3,
+                                ),
+                                anchor: FileId(
+                                    3,
+                                ),
+                                dst: "foo2.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_in_use_tree() {
+        check_expect(
+            "quux",
+            r#"
+//- /main.rs
+pub mod foo;
+pub mod bar;
+fn main() {}
+
+//- /foo.rs
+pub struct FooContent;
+
+//- /bar.rs
+use crate::foo<|>::FooContent;
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 11..14,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "quux",
+                                            delete: 8..11,
+                                        },
+                                    ],
+                                },
+                            },
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    3,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "quux",
+                                            delete: 11..14,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "quux.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_in_dir() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod fo<|>o;
+//- /foo/mod.rs
+// emtpy
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 4..7,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 4..7,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "../foo2/mod.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_unusually_nested_mod() {
+        check_expect(
+            "bar",
+            r#"
+//- /lib.rs
+mod outer { mod fo<|>o; }
+
+//- /outer/foo.rs
+// emtpy
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 16..19,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "bar",
+                                            delete: 16..19,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "bar.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_module_rename_in_path() {
+        check(
+            "baz",
+            r#"
+mod <|>foo { pub fn bar() {} }
+
+fn main() { foo::bar(); }
+"#,
+            r#"
+mod baz { pub fn bar() {} }
+
+fn main() { baz::bar(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_filename_and_path() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+fn f() {
+    bar::foo::fun()
+}
+
+//- /bar.rs
+pub mod foo<|>;
+
+//- /bar/foo.rs
+// pub fn fun() {}
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 8..11,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    2,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 8..11,
+                                        },
+                                    ],
+                                },
+                            },
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 27..30,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    3,
+                                ),
+                                anchor: FileId(
+                                    3,
+                                ),
+                                dst: "foo2.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_enum_variant_from_module_1() {
+        check(
+            "Baz",
+            r#"
+mod foo {
+    pub enum Foo { Bar<|> }
+}
+
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Bar => {}
+    }
+}
+"#,
+            r#"
+mod foo {
+    pub enum Foo { Baz }
+}
+
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Baz => {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_enum_variant_from_module_2() {
+        check(
+            "baz",
+            r#"
+mod foo {
+    pub struct Foo { pub bar<|>: uint }
+}
+
+fn foo(f: foo::Foo) {
+    let _ = f.bar;
+}
+"#,
+            r#"
+mod foo {
+    pub struct Foo { pub baz: uint }
+}
+
+fn foo(f: foo::Foo) {
+    let _ = f.baz;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo<|>: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&mut self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_self_to_parameter() {
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&mut <|>self) -> i32 {
+        self.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_self_in_path_to_parameter() {
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&self) -> i32 {
+        let self_var = 1;
+        self<|>.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: &Foo) -> i32 {
+        let self_var = 1;
+        foo.i
+    }
+}
+"#,
+        );
+    }
+}
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
new file mode 100644
index 000000000..c3e07c8de
--- /dev/null
+++ b/crates/ide/src/runnables.rs
@@ -0,0 +1,883 @@
+use std::fmt;
+
+use cfg::CfgExpr;
+use hir::{AsAssocItem, Attrs, HirFileId, InFile, Semantics};
+use ide_db::RootDatabase;
+use itertools::Itertools;
+use syntax::{
+    ast::{self, AstNode, AttrsOwner, DocCommentsOwner, ModuleItemOwner, NameOwner},
+    match_ast, SyntaxNode,
+};
+
+use crate::{display::ToNav, FileId, NavigationTarget};
+
+#[derive(Debug, Clone)]
+pub struct Runnable {
+    pub nav: NavigationTarget,
+    pub kind: RunnableKind,
+    pub cfg_exprs: Vec<CfgExpr>,
+}
+
+#[derive(Debug, Clone)]
+pub enum TestId {
+    Name(String),
+    Path(String),
+}
+
+impl fmt::Display for TestId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            TestId::Name(name) => write!(f, "{}", name),
+            TestId::Path(path) => write!(f, "{}", path),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum RunnableKind {
+    Test { test_id: TestId, attr: TestAttr },
+    TestMod { path: String },
+    Bench { test_id: TestId },
+    DocTest { test_id: TestId },
+    Bin,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct RunnableAction {
+    pub run_title: &'static str,
+    pub debugee: bool,
+}
+
+const TEST: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Test", debugee: true };
+const DOCTEST: RunnableAction =
+    RunnableAction { run_title: "▶\u{fe0e} Run Doctest", debugee: false };
+const BENCH: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Bench", debugee: true };
+const BIN: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run", debugee: true };
+
+impl Runnable {
+    // test package::module::testname
+    pub fn label(&self, target: Option<String>) -> String {
+        match &self.kind {
+            RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
+            RunnableKind::TestMod { path } => format!("test-mod {}", path),
+            RunnableKind::Bench { test_id } => format!("bench {}", test_id),
+            RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
+            RunnableKind::Bin => {
+                target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
+            }
+        }
+    }
+
+    pub fn action(&self) -> &'static RunnableAction {
+        match &self.kind {
+            RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => &TEST,
+            RunnableKind::DocTest { .. } => &DOCTEST,
+            RunnableKind::Bench { .. } => &BENCH,
+            RunnableKind::Bin => &BIN,
+        }
+    }
+}
+
+// Feature: Run
+//
+// Shows a popup suggesting to run a test/benchmark/binary **at the current cursor
+// location**. Super useful for repeatedly running just a single test. Do bind this
+// to a shortcut!
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Run**
+// |===
+pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
+    let sema = Semantics::new(db);
+    let source_file = sema.parse(file_id);
+    source_file.syntax().descendants().filter_map(|i| runnable(&sema, i, file_id)).collect()
+}
+
+pub(crate) fn runnable(
+    sema: &Semantics<RootDatabase>,
+    item: SyntaxNode,
+    file_id: FileId,
+) -> Option<Runnable> {
+    match_ast! {
+        match item {
+            ast::Fn(it) => runnable_fn(sema, it, file_id),
+            ast::Module(it) => runnable_mod(sema, it, file_id),
+            _ => None,
+        }
+    }
+}
+
+fn runnable_fn(
+    sema: &Semantics<RootDatabase>,
+    fn_def: ast::Fn,
+    file_id: FileId,
+) -> Option<Runnable> {
+    let name_string = fn_def.name()?.text().to_string();
+
+    let kind = if name_string == "main" {
+        RunnableKind::Bin
+    } else {
+        let test_id = match sema.to_def(&fn_def).map(|def| def.module(sema.db)) {
+            Some(module) => {
+                let def = sema.to_def(&fn_def)?;
+                let impl_trait_name = def.as_assoc_item(sema.db).and_then(|assoc_item| {
+                    match assoc_item.container(sema.db) {
+                        hir::AssocItemContainer::Trait(trait_item) => {
+                            Some(trait_item.name(sema.db).to_string())
+                        }
+                        hir::AssocItemContainer::ImplDef(impl_def) => impl_def
+                            .target_ty(sema.db)
+                            .as_adt()
+                            .map(|adt| adt.name(sema.db).to_string()),
+                    }
+                });
+
+                let path_iter = module
+                    .path_to_root(sema.db)
+                    .into_iter()
+                    .rev()
+                    .filter_map(|it| it.name(sema.db))
+                    .map(|name| name.to_string());
+
+                let path = if let Some(impl_trait_name) = impl_trait_name {
+                    path_iter
+                        .chain(std::iter::once(impl_trait_name))
+                        .chain(std::iter::once(name_string))
+                        .join("::")
+                } else {
+                    path_iter.chain(std::iter::once(name_string)).join("::")
+                };
+
+                TestId::Path(path)
+            }
+            None => TestId::Name(name_string),
+        };
+
+        if has_test_related_attribute(&fn_def) {
+            let attr = TestAttr::from_fn(&fn_def);
+            RunnableKind::Test { test_id, attr }
+        } else if fn_def.has_atom_attr("bench") {
+            RunnableKind::Bench { test_id }
+        } else if has_doc_test(&fn_def) {
+            RunnableKind::DocTest { test_id }
+        } else {
+            return None;
+        }
+    };
+
+    let attrs = Attrs::from_attrs_owner(sema.db, InFile::new(HirFileId::from(file_id), &fn_def));
+    let cfg_exprs = attrs.cfg().collect();
+
+    let nav = if let RunnableKind::DocTest { .. } = kind {
+        NavigationTarget::from_doc_commented(
+            sema.db,
+            InFile::new(file_id.into(), &fn_def),
+            InFile::new(file_id.into(), &fn_def),
+        )
+    } else {
+        NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def))
+    };
+    Some(Runnable { nav, kind, cfg_exprs })
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct TestAttr {
+    pub ignore: bool,
+}
+
+impl TestAttr {
+    fn from_fn(fn_def: &ast::Fn) -> TestAttr {
+        let ignore = fn_def
+            .attrs()
+            .filter_map(|attr| attr.simple_name())
+            .any(|attribute_text| attribute_text == "ignore");
+        TestAttr { ignore }
+    }
+}
+
+/// This is a method with a heuristics to support test methods annotated with custom test annotations, such as
+/// `#[test_case(...)]`, `#[tokio::test]` and similar.
+/// Also a regular `#[test]` annotation is supported.
+///
+/// It may produce false positives, for example, `#[wasm_bindgen_test]` requires a different command to run the test,
+/// but it's better than not to have the runnables for the tests at all.
+fn has_test_related_attribute(fn_def: &ast::Fn) -> bool {
+    fn_def
+        .attrs()
+        .filter_map(|attr| attr.path())
+        .map(|path| path.syntax().to_string().to_lowercase())
+        .any(|attribute_text| attribute_text.contains("test"))
+}
+
+fn has_doc_test(fn_def: &ast::Fn) -> bool {
+    fn_def.doc_comment_text().map_or(false, |comment| comment.contains("```"))
+}
+
+fn runnable_mod(
+    sema: &Semantics<RootDatabase>,
+    module: ast::Module,
+    file_id: FileId,
+) -> Option<Runnable> {
+    if !has_test_function_or_multiple_test_submodules(&module) {
+        return None;
+    }
+    let module_def = sema.to_def(&module)?;
+
+    let path = module_def
+        .path_to_root(sema.db)
+        .into_iter()
+        .rev()
+        .filter_map(|it| it.name(sema.db))
+        .join("::");
+
+    let attrs = Attrs::from_attrs_owner(sema.db, InFile::new(HirFileId::from(file_id), &module));
+    let cfg_exprs = attrs.cfg().collect();
+    let nav = module_def.to_nav(sema.db);
+    Some(Runnable { nav, kind: RunnableKind::TestMod { path }, cfg_exprs })
+}
+
+// We could create runnables for modules with number_of_test_submodules > 0,
+// but that bloats the runnables for no real benefit, since all tests can be run by the submodule already
+fn has_test_function_or_multiple_test_submodules(module: &ast::Module) -> bool {
+    if let Some(item_list) = module.item_list() {
+        let mut number_of_test_submodules = 0;
+
+        for item in item_list.items() {
+            match item {
+                ast::Item::Fn(f) => {
+                    if has_test_related_attribute(&f) {
+                        return true;
+                    }
+                }
+                ast::Item::Module(submodule) => {
+                    if has_test_function_or_multiple_test_submodules(&submodule) {
+                        number_of_test_submodules += 1;
+                    }
+                }
+                _ => (),
+            }
+        }
+
+        number_of_test_submodules > 1
+    } else {
+        false
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+
+    use crate::mock_analysis::analysis_and_position;
+
+    use super::{RunnableAction, BENCH, BIN, DOCTEST, TEST};
+
+    fn check(
+        ra_fixture: &str,
+        // FIXME: fold this into `expect` as well
+        actions: &[&RunnableAction],
+        expect: Expect,
+    ) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let runnables = analysis.runnables(position.file_id).unwrap();
+        expect.assert_debug_eq(&runnables);
+        assert_eq!(
+            actions,
+            runnables.into_iter().map(|it| it.action()).collect::<Vec<_>>().as_slice()
+        );
+    }
+
+    #[test]
+    fn test_runnables() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+fn main() {}
+
+#[test]
+fn test_foo() {}
+
+#[test]
+#[ignore]
+fn test_foo() {}
+
+#[bench]
+fn bench() {}
+"#,
+            &[&BIN, &TEST, &TEST, &BENCH],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            name: "main",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 15..39,
+                            focus_range: Some(
+                                26..34,
+                            ),
+                            name: "test_foo",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 41..75,
+                            focus_range: Some(
+                                62..70,
+                            ),
+                            name: "test_foo",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo",
+                            ),
+                            attr: TestAttr {
+                                ignore: true,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 77..99,
+                            focus_range: Some(
+                                89..94,
+                            ),
+                            name: "bench",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bench {
+                            test_id: Path(
+                                "bench",
+                            ),
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_doc_test() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+fn main() {}
+
+/// ```
+/// let x = 5;
+/// ```
+fn foo() {}
+"#,
+            &[&BIN, &DOCTEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            name: "main",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 15..57,
+                            focus_range: None,
+                            name: "foo",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: DocTest {
+                            test_id: Path(
+                                "foo",
+                            ),
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_doc_test_in_impl() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+fn main() {}
+
+struct Data;
+impl Data {
+    /// ```
+    /// let x = 5;
+    /// ```
+    fn foo() {}
+}
+"#,
+            &[&BIN, &DOCTEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            name: "main",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 44..98,
+                            focus_range: None,
+                            name: "foo",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: DocTest {
+                            test_id: Path(
+                                "Data::foo",
+                            ),
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_module() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+mod test_mod {
+    #[test]
+    fn test_foo1() {}
+}
+"#,
+            &[&TEST, &TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..51,
+                            focus_range: Some(
+                                5..13,
+                            ),
+                            name: "test_mod",
+                            kind: MODULE,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "test_mod",
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 20..49,
+                            focus_range: Some(
+                                35..44,
+                            ),
+                            name: "test_foo1",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_mod::test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn only_modules_with_test_functions_or_more_than_one_test_submodule_have_runners() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+mod root_tests {
+    mod nested_tests_0 {
+        mod nested_tests_1 {
+            #[test]
+            fn nested_test_11() {}
+
+            #[test]
+            fn nested_test_12() {}
+        }
+
+        mod nested_tests_2 {
+            #[test]
+            fn nested_test_2() {}
+        }
+
+        mod nested_tests_3 {}
+    }
+
+    mod nested_tests_4 {}
+}
+"#,
+            &[&TEST, &TEST, &TEST, &TEST, &TEST, &TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 22..323,
+                            focus_range: Some(
+                                26..40,
+                            ),
+                            name: "nested_tests_0",
+                            kind: MODULE,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "root_tests::nested_tests_0",
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 51..192,
+                            focus_range: Some(
+                                55..69,
+                            ),
+                            name: "nested_tests_1",
+                            kind: MODULE,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "root_tests::nested_tests_0::nested_tests_1",
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 84..126,
+                            focus_range: Some(
+                                107..121,
+                            ),
+                            name: "nested_test_11",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "root_tests::nested_tests_0::nested_tests_1::nested_test_11",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 140..182,
+                            focus_range: Some(
+                                163..177,
+                            ),
+                            name: "nested_test_12",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "root_tests::nested_tests_0::nested_tests_1::nested_test_12",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 202..286,
+                            focus_range: Some(
+                                206..220,
+                            ),
+                            name: "nested_tests_2",
+                            kind: MODULE,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "root_tests::nested_tests_0::nested_tests_2",
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 235..276,
+                            focus_range: Some(
+                                258..271,
+                            ),
+                            name: "nested_test_2",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "root_tests::nested_tests_0::nested_tests_2::nested_test_2",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_with_feature() {
+        check(
+            r#"
+//- /lib.rs crate:foo cfg:feature=foo
+<|>
+#[test]
+#[cfg(feature = "foo")]
+fn test_foo1() {}
+"#,
+            &[&TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..50,
+                            focus_range: Some(
+                                36..45,
+                            ),
+                            name: "test_foo1",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [
+                            KeyValue {
+                                key: "feature",
+                                value: "foo",
+                            },
+                        ],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_with_features() {
+        check(
+            r#"
+//- /lib.rs crate:foo cfg:feature=foo,feature=bar
+<|>
+#[test]
+#[cfg(all(feature = "foo", feature = "bar"))]
+fn test_foo1() {}
+"#,
+            &[&TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..72,
+                            focus_range: Some(
+                                58..67,
+                            ),
+                            name: "test_foo1",
+                            kind: FN,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [
+                            All(
+                                [
+                                    KeyValue {
+                                        key: "feature",
+                                        value: "foo",
+                                    },
+                                    KeyValue {
+                                        key: "feature",
+                                        value: "bar",
+                                    },
+                                ],
+                            ),
+                        ],
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_runnables_no_test_function_in_module() {
+        check(
+            r#"
+//- /lib.rs
+<|>
+mod test_mod {
+    fn foo1() {}
+}
+"#,
+            &[],
+            expect![[r#"
+                []
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide/src/status.rs b/crates/ide/src/status.rs
new file mode 100644
index 000000000..c23708181
--- /dev/null
+++ b/crates/ide/src/status.rs
@@ -0,0 +1,145 @@
+use std::{fmt, iter::FromIterator, sync::Arc};
+
+use base_db::{
+    salsa::debug::{DebugQueryTable, TableEntry},
+    FileTextQuery, SourceRootId,
+};
+use hir::MacroFile;
+use ide_db::{
+    symbol_index::{LibrarySymbolsQuery, SymbolIndex},
+    RootDatabase,
+};
+use profile::{memory_usage, Bytes};
+use rustc_hash::FxHashMap;
+use syntax::{ast, Parse, SyntaxNode};
+
+use crate::FileId;
+
+fn syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
+    base_db::ParseQuery.in_db(db).entries::<SyntaxTreeStats>()
+}
+fn macro_syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
+    hir::db::ParseMacroQuery.in_db(db).entries::<SyntaxTreeStats>()
+}
+
+// Feature: Status
+//
+// Shows internal statistic about memory usage of rust-analyzer.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Status**
+// |===
+pub(crate) fn status(db: &RootDatabase) -> String {
+    let files_stats = FileTextQuery.in_db(db).entries::<FilesStats>();
+    let syntax_tree_stats = syntax_tree_stats(db);
+    let macro_syntax_tree_stats = macro_syntax_tree_stats(db);
+    let symbols_stats = LibrarySymbolsQuery.in_db(db).entries::<LibrarySymbolsStats>();
+    format!(
+        "{}\n{}\n{}\n{} (macros)\n\n\nmemory:\n{}\ngc {:?} seconds ago",
+        files_stats,
+        symbols_stats,
+        syntax_tree_stats,
+        macro_syntax_tree_stats,
+        memory_usage(),
+        db.last_gc.elapsed().as_secs(),
+    )
+}
+
+#[derive(Default)]
+struct FilesStats {
+    total: usize,
+    size: Bytes,
+}
+
+impl fmt::Display for FilesStats {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{} ({}) files", self.total, self.size)
+    }
+}
+
+impl FromIterator<TableEntry<FileId, Arc<String>>> for FilesStats {
+    fn from_iter<T>(iter: T) -> FilesStats
+    where
+        T: IntoIterator<Item = TableEntry<FileId, Arc<String>>>,
+    {
+        let mut res = FilesStats::default();
+        for entry in iter {
+            res.total += 1;
+            res.size += entry.value.unwrap().len();
+        }
+        res
+    }
+}
+
+#[derive(Default)]
+pub(crate) struct SyntaxTreeStats {
+    total: usize,
+    pub(crate) retained: usize,
+}
+
+impl fmt::Display for SyntaxTreeStats {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{} trees, {} retained", self.total, self.retained)
+    }
+}
+
+impl FromIterator<TableEntry<FileId, Parse<ast::SourceFile>>> for SyntaxTreeStats {
+    fn from_iter<T>(iter: T) -> SyntaxTreeStats
+    where
+        T: IntoIterator<Item = TableEntry<FileId, Parse<ast::SourceFile>>>,
+    {
+        let mut res = SyntaxTreeStats::default();
+        for entry in iter {
+            res.total += 1;
+            res.retained += entry.value.is_some() as usize;
+        }
+        res
+    }
+}
+
+impl<M> FromIterator<TableEntry<MacroFile, Option<(Parse<SyntaxNode>, M)>>> for SyntaxTreeStats {
+    fn from_iter<T>(iter: T) -> SyntaxTreeStats
+    where
+        T: IntoIterator<Item = TableEntry<MacroFile, Option<(Parse<SyntaxNode>, M)>>>,
+    {
+        let mut res = SyntaxTreeStats::default();
+        for entry in iter {
+            res.total += 1;
+            res.retained += entry.value.is_some() as usize;
+        }
+        res
+    }
+}
+
+#[derive(Default)]
+struct LibrarySymbolsStats {
+    total: usize,
+    size: Bytes,
+}
+
+impl fmt::Display for LibrarySymbolsStats {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{} ({}) symbols", self.total, self.size)
+    }
+}
+
+impl FromIterator<TableEntry<(), Arc<FxHashMap<SourceRootId, SymbolIndex>>>>
+    for LibrarySymbolsStats
+{
+    fn from_iter<T>(iter: T) -> LibrarySymbolsStats
+    where
+        T: IntoIterator<Item = TableEntry<(), Arc<FxHashMap<SourceRootId, SymbolIndex>>>>,
+    {
+        let mut res = LibrarySymbolsStats::default();
+        for entry in iter {
+            let value = entry.value.unwrap();
+            for symbols in value.values() {
+                res.total += symbols.len();
+                res.size += symbols.memory_size();
+            }
+        }
+        res
+    }
+}
diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
new file mode 100644
index 000000000..5d7c7e8d0
--- /dev/null
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -0,0 +1,872 @@
+mod tags;
+mod html;
+mod injection;
+#[cfg(test)]
+mod tests;
+
+use hir::{Name, Semantics, VariantDef};
+use ide_db::{
+    defs::{classify_name, classify_name_ref, Definition, NameClass, NameRefClass},
+    RootDatabase,
+};
+use rustc_hash::FxHashMap;
+use syntax::{
+    ast::{self, HasFormatSpecifier},
+    AstNode, AstToken, Direction, NodeOrToken, SyntaxElement,
+    SyntaxKind::*,
+    TextRange, WalkEvent, T,
+};
+
+use crate::FileId;
+
+use ast::FormatSpecifier;
+pub(crate) use html::highlight_as_html;
+pub use tags::{Highlight, HighlightModifier, HighlightModifiers, HighlightTag};
+
+#[derive(Debug, Clone)]
+pub struct HighlightedRange {
+    pub range: TextRange,
+    pub highlight: Highlight,
+    pub binding_hash: Option<u64>,
+}
+
+// Feature: Semantic Syntax Highlighting
+//
+// rust-analyzer highlights the code semantically.
+// For example, `bar` in `foo::Bar` might be colored differently depending on whether `Bar` is an enum or a trait.
+// rust-analyzer does not specify colors directly, instead it assigns tag (like `struct`) and a set of modifiers (like `declaration`) to each token.
+// It's up to the client to map those to specific colors.
+//
+// The general rule is that a reference to an entity gets colored the same way as the entity itself.
+// We also give special modifier for `mut` and `&mut` local variables.
+pub(crate) fn highlight(
+    db: &RootDatabase,
+    file_id: FileId,
+    range_to_highlight: Option<TextRange>,
+    syntactic_name_ref_highlighting: bool,
+) -> Vec<HighlightedRange> {
+    let _p = profile::span("highlight");
+    let sema = Semantics::new(db);
+
+    // Determine the root based on the given range.
+    let (root, range_to_highlight) = {
+        let source_file = sema.parse(file_id);
+        match range_to_highlight {
+            Some(range) => {
+                let node = match source_file.syntax().covering_element(range) {
+                    NodeOrToken::Node(it) => it,
+                    NodeOrToken::Token(it) => it.parent(),
+                };
+                (node, range)
+            }
+            None => (source_file.syntax().clone(), source_file.syntax().text_range()),
+        }
+    };
+
+    let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
+    // We use a stack for the DFS traversal below.
+    // When we leave a node, the we use it to flatten the highlighted ranges.
+    let mut stack = HighlightedRangeStack::new();
+
+    let mut current_macro_call: Option<ast::MacroCall> = None;
+    let mut format_string: Option<SyntaxElement> = None;
+
+    // Walk all nodes, keeping track of whether we are inside a macro or not.
+    // If in macro, expand it first and highlight the expanded code.
+    for event in root.preorder_with_tokens() {
+        match &event {
+            WalkEvent::Enter(_) => stack.push(),
+            WalkEvent::Leave(_) => stack.pop(),
+        };
+
+        let event_range = match &event {
+            WalkEvent::Enter(it) => it.text_range(),
+            WalkEvent::Leave(it) => it.text_range(),
+        };
+
+        // Element outside of the viewport, no need to highlight
+        if range_to_highlight.intersect(event_range).is_none() {
+            continue;
+        }
+
+        // Track "inside macro" state
+        match event.clone().map(|it| it.into_node().and_then(ast::MacroCall::cast)) {
+            WalkEvent::Enter(Some(mc)) => {
+                current_macro_call = Some(mc.clone());
+                if let Some(range) = macro_call_range(&mc) {
+                    stack.add(HighlightedRange {
+                        range,
+                        highlight: HighlightTag::Macro.into(),
+                        binding_hash: None,
+                    });
+                }
+                if let Some(name) = mc.is_macro_rules() {
+                    if let Some((highlight, binding_hash)) = highlight_element(
+                        &sema,
+                        &mut bindings_shadow_count,
+                        syntactic_name_ref_highlighting,
+                        name.syntax().clone().into(),
+                    ) {
+                        stack.add(HighlightedRange {
+                            range: name.syntax().text_range(),
+                            highlight,
+                            binding_hash,
+                        });
+                    }
+                }
+                continue;
+            }
+            WalkEvent::Leave(Some(mc)) => {
+                assert!(current_macro_call == Some(mc));
+                current_macro_call = None;
+                format_string = None;
+            }
+            _ => (),
+        }
+
+        // Check for Rust code in documentation
+        match &event {
+            WalkEvent::Leave(NodeOrToken::Node(node)) => {
+                if let Some((doctest, range_mapping, new_comments)) =
+                    injection::extract_doc_comments(node)
+                {
+                    injection::highlight_doc_comment(
+                        doctest,
+                        range_mapping,
+                        new_comments,
+                        &mut stack,
+                    );
+                }
+            }
+            _ => (),
+        }
+
+        let element = match event {
+            WalkEvent::Enter(it) => it,
+            WalkEvent::Leave(_) => continue,
+        };
+
+        let range = element.text_range();
+
+        let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
+            // Inside a macro -- expand it first
+            let token = match element.clone().into_token() {
+                Some(it) if it.parent().kind() == TOKEN_TREE => it,
+                _ => continue,
+            };
+            let token = sema.descend_into_macros(token.clone());
+            let parent = token.parent();
+
+            // Check if macro takes a format string and remember it for highlighting later.
+            // The macros that accept a format string expand to a compiler builtin macros
+            // `format_args` and `format_args_nl`.
+            if let Some(name) = parent
+                .parent()
+                .and_then(ast::MacroCall::cast)
+                .and_then(|mc| mc.path())
+                .and_then(|p| p.segment())
+                .and_then(|s| s.name_ref())
+            {
+                match name.text().as_str() {
+                    "format_args" | "format_args_nl" => {
+                        format_string = parent
+                            .children_with_tokens()
+                            .filter(|t| t.kind() != WHITESPACE)
+                            .nth(1)
+                            .filter(|e| {
+                                ast::String::can_cast(e.kind())
+                                    || ast::RawString::can_cast(e.kind())
+                            })
+                    }
+                    _ => {}
+                }
+            }
+
+            // We only care Name and Name_ref
+            match (token.kind(), parent.kind()) {
+                (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
+                _ => token.into(),
+            }
+        } else {
+            element.clone()
+        };
+
+        if let Some(token) = element.as_token().cloned().and_then(ast::RawString::cast) {
+            let expanded = element_to_highlight.as_token().unwrap().clone();
+            if injection::highlight_injection(&mut stack, &sema, token, expanded).is_some() {
+                continue;
+            }
+        }
+
+        let is_format_string = format_string.as_ref() == Some(&element_to_highlight);
+
+        if let Some((highlight, binding_hash)) = highlight_element(
+            &sema,
+            &mut bindings_shadow_count,
+            syntactic_name_ref_highlighting,
+            element_to_highlight.clone(),
+        ) {
+            stack.add(HighlightedRange { range, highlight, binding_hash });
+            if let Some(string) =
+                element_to_highlight.as_token().cloned().and_then(ast::String::cast)
+            {
+                if is_format_string {
+                    stack.push();
+                    string.lex_format_specifier(|piece_range, kind| {
+                        if let Some(highlight) = highlight_format_specifier(kind) {
+                            stack.add(HighlightedRange {
+                                range: piece_range + range.start(),
+                                highlight: highlight.into(),
+                                binding_hash: None,
+                            });
+                        }
+                    });
+                    stack.pop();
+                }
+                // Highlight escape sequences
+                if let Some(char_ranges) = string.char_ranges() {
+                    stack.push();
+                    for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
+                        if string.text()[piece_range.start().into()..].starts_with('\\') {
+                            stack.add(HighlightedRange {
+                                range: piece_range + range.start(),
+                                highlight: HighlightTag::EscapeSequence.into(),
+                                binding_hash: None,
+                            });
+                        }
+                    }
+                    stack.pop_and_inject(None);
+                }
+            } else if let Some(string) =
+                element_to_highlight.as_token().cloned().and_then(ast::RawString::cast)
+            {
+                if is_format_string {
+                    stack.push();
+                    string.lex_format_specifier(|piece_range, kind| {
+                        if let Some(highlight) = highlight_format_specifier(kind) {
+                            stack.add(HighlightedRange {
+                                range: piece_range + range.start(),
+                                highlight: highlight.into(),
+                                binding_hash: None,
+                            });
+                        }
+                    });
+                    stack.pop();
+                }
+            }
+        }
+    }
+
+    stack.flattened()
+}
+
+#[derive(Debug)]
+struct HighlightedRangeStack {
+    stack: Vec<Vec<HighlightedRange>>,
+}
+
+/// We use a stack to implement the flattening logic for the highlighted
+/// syntax ranges.
+impl HighlightedRangeStack {
+    fn new() -> Self {
+        Self { stack: vec![Vec::new()] }
+    }
+
+    fn push(&mut self) {
+        self.stack.push(Vec::new());
+    }
+
+    /// Flattens the highlighted ranges.
+    ///
+    /// For example `#[cfg(feature = "foo")]` contains the nested ranges:
+    /// 1) parent-range: Attribute [0, 23)
+    /// 2) child-range: String [16, 21)
+    ///
+    /// The following code implements the flattening, for our example this results to:
+    /// `[Attribute [0, 16), String [16, 21), Attribute [21, 23)]`
+    fn pop(&mut self) {
+        let children = self.stack.pop().unwrap();
+        let prev = self.stack.last_mut().unwrap();
+        let needs_flattening = !children.is_empty()
+            && !prev.is_empty()
+            && prev.last().unwrap().range.contains_range(children.first().unwrap().range);
+        if !needs_flattening {
+            prev.extend(children);
+        } else {
+            let mut parent = prev.pop().unwrap();
+            for ele in children {
+                assert!(parent.range.contains_range(ele.range));
+
+                let cloned = Self::intersect(&mut parent, &ele);
+                if !parent.range.is_empty() {
+                    prev.push(parent);
+                }
+                prev.push(ele);
+                parent = cloned;
+            }
+            if !parent.range.is_empty() {
+                prev.push(parent);
+            }
+        }
+    }
+
+    /// Intersects the `HighlightedRange` `parent` with `child`.
+    /// `parent` is mutated in place, becoming the range before `child`.
+    /// Returns the range (of the same type as `parent`) *after* `child`.
+    fn intersect(parent: &mut HighlightedRange, child: &HighlightedRange) -> HighlightedRange {
+        assert!(parent.range.contains_range(child.range));
+
+        let mut cloned = parent.clone();
+        parent.range = TextRange::new(parent.range.start(), child.range.start());
+        cloned.range = TextRange::new(child.range.end(), cloned.range.end());
+
+        cloned
+    }
+
+    /// Remove the `HighlightRange` of `parent` that's currently covered by `child`.
+    fn intersect_partial(parent: &mut HighlightedRange, child: &HighlightedRange) {
+        assert!(
+            parent.range.start() <= child.range.start()
+                && parent.range.end() >= child.range.start()
+                && child.range.end() > parent.range.end()
+        );
+
+        parent.range = TextRange::new(parent.range.start(), child.range.start());
+    }
+
+    /// Similar to `pop`, but can modify arbitrary prior ranges (where `pop`)
+    /// can only modify the last range currently on the stack.
+    /// Can be used to do injections that span multiple ranges, like the
+    /// doctest injection below.
+    /// If `overwrite_parent` is non-optional, the highlighting of the parent range
+    /// is overwritten with the argument.
+    ///
+    /// Note that `pop` can be simulated by `pop_and_inject(false)` but the
+    /// latter is computationally more expensive.
+    fn pop_and_inject(&mut self, overwrite_parent: Option<Highlight>) {
+        let mut children = self.stack.pop().unwrap();
+        let prev = self.stack.last_mut().unwrap();
+        children.sort_by_key(|range| range.range.start());
+        prev.sort_by_key(|range| range.range.start());
+
+        for child in children {
+            if let Some(idx) =
+                prev.iter().position(|parent| parent.range.contains_range(child.range))
+            {
+                if let Some(tag) = overwrite_parent {
+                    prev[idx].highlight = tag;
+                }
+
+                let cloned = Self::intersect(&mut prev[idx], &child);
+                let insert_idx = if prev[idx].range.is_empty() {
+                    prev.remove(idx);
+                    idx
+                } else {
+                    idx + 1
+                };
+                prev.insert(insert_idx, child);
+                if !cloned.range.is_empty() {
+                    prev.insert(insert_idx + 1, cloned);
+                }
+            } else {
+                let maybe_idx =
+                    prev.iter().position(|parent| parent.range.contains(child.range.start()));
+                match (overwrite_parent, maybe_idx) {
+                    (Some(_), Some(idx)) => {
+                        Self::intersect_partial(&mut prev[idx], &child);
+                        let insert_idx = if prev[idx].range.is_empty() {
+                            prev.remove(idx);
+                            idx
+                        } else {
+                            idx + 1
+                        };
+                        prev.insert(insert_idx, child);
+                    }
+                    (_, None) => {
+                        let idx = prev
+                            .binary_search_by_key(&child.range.start(), |range| range.range.start())
+                            .unwrap_or_else(|x| x);
+                        prev.insert(idx, child);
+                    }
+                    _ => {
+                        unreachable!("child range should be completely contained in parent range");
+                    }
+                }
+            }
+        }
+    }
+
+    fn add(&mut self, range: HighlightedRange) {
+        self.stack
+            .last_mut()
+            .expect("during DFS traversal, the stack must not be empty")
+            .push(range)
+    }
+
+    fn flattened(mut self) -> Vec<HighlightedRange> {
+        assert_eq!(
+            self.stack.len(),
+            1,
+            "after DFS traversal, the stack should only contain a single element"
+        );
+        let mut res = self.stack.pop().unwrap();
+        res.sort_by_key(|range| range.range.start());
+        // Check that ranges are sorted and disjoint
+        assert!(res
+            .iter()
+            .zip(res.iter().skip(1))
+            .all(|(left, right)| left.range.end() <= right.range.start()));
+        res
+    }
+}
+
+fn highlight_format_specifier(kind: FormatSpecifier) -> Option<HighlightTag> {
+    Some(match kind {
+        FormatSpecifier::Open
+        | FormatSpecifier::Close
+        | FormatSpecifier::Colon
+        | FormatSpecifier::Fill
+        | FormatSpecifier::Align
+        | FormatSpecifier::Sign
+        | FormatSpecifier::NumberSign
+        | FormatSpecifier::DollarSign
+        | FormatSpecifier::Dot
+        | FormatSpecifier::Asterisk
+        | FormatSpecifier::QuestionMark => HighlightTag::FormatSpecifier,
+        FormatSpecifier::Integer | FormatSpecifier::Zero => HighlightTag::NumericLiteral,
+        FormatSpecifier::Identifier => HighlightTag::Local,
+    })
+}
+
+fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
+    let path = macro_call.path()?;
+    let name_ref = path.segment()?.name_ref()?;
+
+    let range_start = name_ref.syntax().text_range().start();
+    let mut range_end = name_ref.syntax().text_range().end();
+    for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
+        match sibling.kind() {
+            T![!] | IDENT => range_end = sibling.text_range().end(),
+            _ => (),
+        }
+    }
+
+    Some(TextRange::new(range_start, range_end))
+}
+
+fn is_possibly_unsafe(name_ref: &ast::NameRef) -> bool {
+    name_ref
+        .syntax()
+        .parent()
+        .and_then(|parent| {
+            ast::FieldExpr::cast(parent.clone())
+                .map(|_| true)
+                .or_else(|| ast::RecordPatField::cast(parent).map(|_| true))
+        })
+        .unwrap_or(false)
+}
+
+fn highlight_element(
+    sema: &Semantics<RootDatabase>,
+    bindings_shadow_count: &mut FxHashMap<Name, u32>,
+    syntactic_name_ref_highlighting: bool,
+    element: SyntaxElement,
+) -> Option<(Highlight, Option<u64>)> {
+    let db = sema.db;
+    let mut binding_hash = None;
+    let highlight: Highlight = match element.kind() {
+        FN => {
+            bindings_shadow_count.clear();
+            return None;
+        }
+
+        // Highlight definitions depending on the "type" of the definition.
+        NAME => {
+            let name = element.into_node().and_then(ast::Name::cast).unwrap();
+            let name_kind = classify_name(sema, &name);
+
+            if let Some(NameClass::Definition(Definition::Local(local))) = &name_kind {
+                if let Some(name) = local.name(db) {
+                    let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
+                    *shadow_count += 1;
+                    binding_hash = Some(calc_binding_hash(&name, *shadow_count))
+                }
+            };
+
+            match name_kind {
+                Some(NameClass::ExternCrate(_)) => HighlightTag::Module.into(),
+                Some(NameClass::Definition(def)) => {
+                    highlight_name(sema, db, def, None, false) | HighlightModifier::Definition
+                }
+                Some(NameClass::ConstReference(def)) => highlight_name(sema, db, def, None, false),
+                Some(NameClass::FieldShorthand { field, .. }) => {
+                    let mut h = HighlightTag::Field.into();
+                    if let Definition::Field(field) = field {
+                        if let VariantDef::Union(_) = field.parent_def(db) {
+                            h |= HighlightModifier::Unsafe;
+                        }
+                    }
+
+                    h
+                }
+                None => highlight_name_by_syntax(name) | HighlightModifier::Definition,
+            }
+        }
+
+        // Highlight references like the definitions they resolve to
+        NAME_REF if element.ancestors().any(|it| it.kind() == ATTR) => {
+            Highlight::from(HighlightTag::Function) | HighlightModifier::Attribute
+        }
+        NAME_REF => {
+            let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
+            let possibly_unsafe = is_possibly_unsafe(&name_ref);
+            match classify_name_ref(sema, &name_ref) {
+                Some(name_kind) => match name_kind {
+                    NameRefClass::ExternCrate(_) => HighlightTag::Module.into(),
+                    NameRefClass::Definition(def) => {
+                        if let Definition::Local(local) = &def {
+                            if let Some(name) = local.name(db) {
+                                let shadow_count =
+                                    bindings_shadow_count.entry(name.clone()).or_default();
+                                binding_hash = Some(calc_binding_hash(&name, *shadow_count))
+                            }
+                        };
+                        highlight_name(sema, db, def, Some(name_ref), possibly_unsafe)
+                    }
+                    NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
+                },
+                None if syntactic_name_ref_highlighting => {
+                    highlight_name_ref_by_syntax(name_ref, sema)
+                }
+                None => HighlightTag::UnresolvedReference.into(),
+            }
+        }
+
+        // Simple token-based highlighting
+        COMMENT => {
+            let comment = element.into_token().and_then(ast::Comment::cast)?;
+            let h = HighlightTag::Comment;
+            match comment.kind().doc {
+                Some(_) => h | HighlightModifier::Documentation,
+                None => h.into(),
+            }
+        }
+        STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => HighlightTag::StringLiteral.into(),
+        ATTR => HighlightTag::Attribute.into(),
+        INT_NUMBER | FLOAT_NUMBER => HighlightTag::NumericLiteral.into(),
+        BYTE => HighlightTag::ByteLiteral.into(),
+        CHAR => HighlightTag::CharLiteral.into(),
+        QUESTION => Highlight::new(HighlightTag::Operator) | HighlightModifier::ControlFlow,
+        LIFETIME => {
+            let h = Highlight::new(HighlightTag::Lifetime);
+            match element.parent().map(|it| it.kind()) {
+                Some(LIFETIME_PARAM) | Some(LABEL) => h | HighlightModifier::Definition,
+                _ => h,
+            }
+        }
+        p if p.is_punct() => match p {
+            T![&] => {
+                let h = HighlightTag::Operator.into();
+                let is_unsafe = element
+                    .parent()
+                    .and_then(ast::RefExpr::cast)
+                    .map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr))
+                    .unwrap_or(false);
+                if is_unsafe {
+                    h | HighlightModifier::Unsafe
+                } else {
+                    h
+                }
+            }
+            T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] => HighlightTag::Operator.into(),
+            T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
+                HighlightTag::Macro.into()
+            }
+            T![*] if element.parent().and_then(ast::PtrType::cast).is_some() => {
+                HighlightTag::Keyword.into()
+            }
+            T![*] if element.parent().and_then(ast::PrefixExpr::cast).is_some() => {
+                let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
+
+                let expr = prefix_expr.expr()?;
+                let ty = sema.type_of_expr(&expr)?;
+                if ty.is_raw_ptr() {
+                    HighlightTag::Operator | HighlightModifier::Unsafe
+                } else if let Some(ast::PrefixOp::Deref) = prefix_expr.op_kind() {
+                    HighlightTag::Operator.into()
+                } else {
+                    HighlightTag::Punctuation.into()
+                }
+            }
+            T![-] if element.parent().and_then(ast::PrefixExpr::cast).is_some() => {
+                HighlightTag::NumericLiteral.into()
+            }
+            _ if element.parent().and_then(ast::PrefixExpr::cast).is_some() => {
+                HighlightTag::Operator.into()
+            }
+            _ if element.parent().and_then(ast::BinExpr::cast).is_some() => {
+                HighlightTag::Operator.into()
+            }
+            _ if element.parent().and_then(ast::RangeExpr::cast).is_some() => {
+                HighlightTag::Operator.into()
+            }
+            _ if element.parent().and_then(ast::RangePat::cast).is_some() => {
+                HighlightTag::Operator.into()
+            }
+            _ if element.parent().and_then(ast::RestPat::cast).is_some() => {
+                HighlightTag::Operator.into()
+            }
+            _ if element.parent().and_then(ast::Attr::cast).is_some() => {
+                HighlightTag::Attribute.into()
+            }
+            _ => HighlightTag::Punctuation.into(),
+        },
+
+        k if k.is_keyword() => {
+            let h = Highlight::new(HighlightTag::Keyword);
+            match k {
+                T![break]
+                | T![continue]
+                | T![else]
+                | T![if]
+                | T![loop]
+                | T![match]
+                | T![return]
+                | T![while]
+                | T![in] => h | HighlightModifier::ControlFlow,
+                T![for] if !is_child_of_impl(&element) => h | HighlightModifier::ControlFlow,
+                T![unsafe] => h | HighlightModifier::Unsafe,
+                T![true] | T![false] => HighlightTag::BoolLiteral.into(),
+                T![self] => {
+                    let self_param_is_mut = element
+                        .parent()
+                        .and_then(ast::SelfParam::cast)
+                        .and_then(|p| p.mut_token())
+                        .is_some();
+                    // closure to enforce lazyness
+                    let self_path = || {
+                        sema.resolve_path(&element.parent()?.parent().and_then(ast::Path::cast)?)
+                    };
+                    if self_param_is_mut
+                        || matches!(self_path(),
+                            Some(hir::PathResolution::Local(local))
+                                if local.is_self(db)
+                                    && (local.is_mut(db) || local.ty(db).is_mutable_reference())
+                        )
+                    {
+                        HighlightTag::SelfKeyword | HighlightModifier::Mutable
+                    } else {
+                        HighlightTag::SelfKeyword.into()
+                    }
+                }
+                T![ref] => element
+                    .parent()
+                    .and_then(ast::IdentPat::cast)
+                    .and_then(|ident_pat| {
+                        if sema.is_unsafe_ident_pat(&ident_pat) {
+                            Some(HighlightModifier::Unsafe)
+                        } else {
+                            None
+                        }
+                    })
+                    .map(|modifier| h | modifier)
+                    .unwrap_or(h),
+                _ => h,
+            }
+        }
+
+        _ => return None,
+    };
+
+    return Some((highlight, binding_hash));
+
+    fn calc_binding_hash(name: &Name, shadow_count: u32) -> u64 {
+        fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
+            use std::{collections::hash_map::DefaultHasher, hash::Hasher};
+
+            let mut hasher = DefaultHasher::new();
+            x.hash(&mut hasher);
+            hasher.finish()
+        }
+
+        hash((name, shadow_count))
+    }
+}
+
+fn is_child_of_impl(element: &SyntaxElement) -> bool {
+    match element.parent() {
+        Some(e) => e.kind() == IMPL,
+        _ => false,
+    }
+}
+
+fn highlight_name(
+    sema: &Semantics<RootDatabase>,
+    db: &RootDatabase,
+    def: Definition,
+    name_ref: Option<ast::NameRef>,
+    possibly_unsafe: bool,
+) -> Highlight {
+    match def {
+        Definition::Macro(_) => HighlightTag::Macro,
+        Definition::Field(field) => {
+            let mut h = HighlightTag::Field.into();
+            if possibly_unsafe {
+                if let VariantDef::Union(_) = field.parent_def(db) {
+                    h |= HighlightModifier::Unsafe;
+                }
+            }
+
+            return h;
+        }
+        Definition::ModuleDef(def) => match def {
+            hir::ModuleDef::Module(_) => HighlightTag::Module,
+            hir::ModuleDef::Function(func) => {
+                let mut h = HighlightTag::Function.into();
+                if func.is_unsafe(db) {
+                    h |= HighlightModifier::Unsafe;
+                } else {
+                    let is_unsafe = name_ref
+                        .and_then(|name_ref| name_ref.syntax().parent())
+                        .and_then(ast::MethodCallExpr::cast)
+                        .map(|method_call_expr| sema.is_unsafe_method_call(method_call_expr))
+                        .unwrap_or(false);
+                    if is_unsafe {
+                        h |= HighlightModifier::Unsafe;
+                    }
+                }
+                return h;
+            }
+            hir::ModuleDef::Adt(hir::Adt::Struct(_)) => HighlightTag::Struct,
+            hir::ModuleDef::Adt(hir::Adt::Enum(_)) => HighlightTag::Enum,
+            hir::ModuleDef::Adt(hir::Adt::Union(_)) => HighlightTag::Union,
+            hir::ModuleDef::EnumVariant(_) => HighlightTag::EnumVariant,
+            hir::ModuleDef::Const(_) => HighlightTag::Constant,
+            hir::ModuleDef::Trait(_) => HighlightTag::Trait,
+            hir::ModuleDef::TypeAlias(_) => HighlightTag::TypeAlias,
+            hir::ModuleDef::BuiltinType(_) => HighlightTag::BuiltinType,
+            hir::ModuleDef::Static(s) => {
+                let mut h = Highlight::new(HighlightTag::Static);
+                if s.is_mut(db) {
+                    h |= HighlightModifier::Mutable;
+                    h |= HighlightModifier::Unsafe;
+                }
+                return h;
+            }
+        },
+        Definition::SelfType(_) => HighlightTag::SelfType,
+        Definition::TypeParam(_) => HighlightTag::TypeParam,
+        Definition::Local(local) => {
+            let tag =
+                if local.is_param(db) { HighlightTag::ValueParam } else { HighlightTag::Local };
+            let mut h = Highlight::new(tag);
+            if local.is_mut(db) || local.ty(db).is_mutable_reference() {
+                h |= HighlightModifier::Mutable;
+            }
+            return h;
+        }
+    }
+    .into()
+}
+
+fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
+    let default = HighlightTag::UnresolvedReference;
+
+    let parent = match name.syntax().parent() {
+        Some(it) => it,
+        _ => return default.into(),
+    };
+
+    let tag = match parent.kind() {
+        STRUCT => HighlightTag::Struct,
+        ENUM => HighlightTag::Enum,
+        UNION => HighlightTag::Union,
+        TRAIT => HighlightTag::Trait,
+        TYPE_ALIAS => HighlightTag::TypeAlias,
+        TYPE_PARAM => HighlightTag::TypeParam,
+        RECORD_FIELD => HighlightTag::Field,
+        MODULE => HighlightTag::Module,
+        FN => HighlightTag::Function,
+        CONST => HighlightTag::Constant,
+        STATIC => HighlightTag::Static,
+        VARIANT => HighlightTag::EnumVariant,
+        IDENT_PAT => HighlightTag::Local,
+        _ => default,
+    };
+
+    tag.into()
+}
+
+fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabase>) -> Highlight {
+    let default = HighlightTag::UnresolvedReference;
+
+    let parent = match name.syntax().parent() {
+        Some(it) => it,
+        _ => return default.into(),
+    };
+
+    match parent.kind() {
+        METHOD_CALL_EXPR => {
+            let mut h = Highlight::new(HighlightTag::Function);
+            let is_unsafe = ast::MethodCallExpr::cast(parent)
+                .map(|method_call_expr| sema.is_unsafe_method_call(method_call_expr))
+                .unwrap_or(false);
+            if is_unsafe {
+                h |= HighlightModifier::Unsafe;
+            }
+
+            h
+        }
+        FIELD_EXPR => {
+            let h = HighlightTag::Field;
+            let is_union = ast::FieldExpr::cast(parent)
+                .and_then(|field_expr| {
+                    let field = sema.resolve_field(&field_expr)?;
+                    Some(if let VariantDef::Union(_) = field.parent_def(sema.db) {
+                        true
+                    } else {
+                        false
+                    })
+                })
+                .unwrap_or(false);
+            if is_union {
+                h | HighlightModifier::Unsafe
+            } else {
+                h.into()
+            }
+        }
+        PATH_SEGMENT => {
+            let path = match parent.parent().and_then(ast::Path::cast) {
+                Some(it) => it,
+                _ => return default.into(),
+            };
+            let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) {
+                Some(it) => it,
+                _ => {
+                    // within path, decide whether it is module or adt by checking for uppercase name
+                    return if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                        HighlightTag::Struct
+                    } else {
+                        HighlightTag::Module
+                    }
+                    .into();
+                }
+            };
+            let parent = match expr.syntax().parent() {
+                Some(it) => it,
+                None => return default.into(),
+            };
+
+            match parent.kind() {
+                CALL_EXPR => HighlightTag::Function.into(),
+                _ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                    HighlightTag::Struct.into()
+                } else {
+                    HighlightTag::Constant
+                }
+                .into(),
+            }
+        }
+        _ => default.into(),
+    }
+}
diff --git a/crates/ide/src/syntax_highlighting/html.rs b/crates/ide/src/syntax_highlighting/html.rs
new file mode 100644
index 000000000..249368ff8
--- /dev/null
+++ b/crates/ide/src/syntax_highlighting/html.rs
@@ -0,0 +1,97 @@
+//! Renders a bit of code as HTML.
+
+use base_db::SourceDatabase;
+use oorandom::Rand32;
+use syntax::{AstNode, TextRange, TextSize};
+
+use crate::{syntax_highlighting::highlight, FileId, RootDatabase};
+
+pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId, rainbow: bool) -> String {
+    let parse = db.parse(file_id);
+
+    fn rainbowify(seed: u64) -> String {
+        let mut rng = Rand32::new(seed);
+        format!(
+            "hsl({h},{s}%,{l}%)",
+            h = rng.rand_range(0..361),
+            s = rng.rand_range(42..99),
+            l = rng.rand_range(40..91),
+        )
+    }
+
+    let ranges = highlight(db, file_id, None, false);
+    let text = parse.tree().syntax().to_string();
+    let mut prev_pos = TextSize::from(0);
+    let mut buf = String::new();
+    buf.push_str(&STYLE);
+    buf.push_str("<pre><code>");
+    for range in &ranges {
+        if range.range.start() > prev_pos {
+            let curr = &text[TextRange::new(prev_pos, range.range.start())];
+            let text = html_escape(curr);
+            buf.push_str(&text);
+        }
+        let curr = &text[TextRange::new(range.range.start(), range.range.end())];
+
+        let class = range.highlight.to_string().replace('.', " ");
+        let color = match (rainbow, range.binding_hash) {
+            (true, Some(hash)) => {
+                format!(" data-binding-hash=\"{}\" style=\"color: {};\"", hash, rainbowify(hash))
+            }
+            _ => "".into(),
+        };
+        buf.push_str(&format!("<span class=\"{}\"{}>{}</span>", class, color, html_escape(curr)));
+
+        prev_pos = range.range.end();
+    }
+    // Add the remaining (non-highlighted) text
+    let curr = &text[TextRange::new(prev_pos, TextSize::of(&text))];
+    let text = html_escape(curr);
+    buf.push_str(&text);
+    buf.push_str("</code></pre>");
+    buf
+}
+
+//FIXME: like, real html escaping
+fn html_escape(text: &str) -> String {
+    text.replace("<", "&lt;").replace(">", "&gt;")
+}
+
+const STYLE: &str = "
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+";
diff --git a/crates/ide/src/syntax_highlighting/injection.rs b/crates/ide/src/syntax_highlighting/injection.rs
new file mode 100644
index 000000000..43f4e6fea
--- /dev/null
+++ b/crates/ide/src/syntax_highlighting/injection.rs
@@ -0,0 +1,187 @@
+//! Syntax highlighting injections such as highlighting of documentation tests.
+
+use std::{collections::BTreeMap, convert::TryFrom};
+
+use ast::{HasQuotes, HasStringValue};
+use hir::Semantics;
+use itertools::Itertools;
+use syntax::{ast, AstToken, SyntaxNode, SyntaxToken, TextRange, TextSize};
+
+use crate::{
+    call_info::ActiveParameter, Analysis, Highlight, HighlightModifier, HighlightTag,
+    HighlightedRange, RootDatabase,
+};
+
+use super::HighlightedRangeStack;
+
+pub(super) fn highlight_injection(
+    acc: &mut HighlightedRangeStack,
+    sema: &Semantics<RootDatabase>,
+    literal: ast::RawString,
+    expanded: SyntaxToken,
+) -> Option<()> {
+    let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
+    if !active_parameter.name.starts_with("ra_fixture") {
+        return None;
+    }
+    let value = literal.value()?;
+    let (analysis, tmp_file_id) = Analysis::from_single_file(value.into_owned());
+
+    if let Some(range) = literal.open_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    for mut h in analysis.highlight(tmp_file_id).unwrap() {
+        if let Some(r) = literal.map_range_up(h.range) {
+            h.range = r;
+            acc.add(h)
+        }
+    }
+
+    if let Some(range) = literal.close_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    Some(())
+}
+
+/// Mapping from extracted documentation code to original code
+type RangesMap = BTreeMap<TextSize, TextSize>;
+
+const RUSTDOC_FENCE: &'static str = "```";
+const RUSTDOC_FENCE_TOKENS: &[&'static str] =
+    &["", "rust", "should_panic", "ignore", "no_run", "compile_fail", "edition2015", "edition2018"];
+
+/// Extracts Rust code from documentation comments as well as a mapping from
+/// the extracted source code back to the original source ranges.
+/// Lastly, a vector of new comment highlight ranges (spanning only the
+/// comment prefix) is returned which is used in the syntax highlighting
+/// injection to replace the previous (line-spanning) comment ranges.
+pub(super) fn extract_doc_comments(
+    node: &SyntaxNode,
+) -> Option<(String, RangesMap, Vec<HighlightedRange>)> {
+    // wrap the doctest into function body to get correct syntax highlighting
+    let prefix = "fn doctest() {\n";
+    let suffix = "}\n";
+    // Mapping from extracted documentation code to original code
+    let mut range_mapping: RangesMap = BTreeMap::new();
+    let mut line_start = TextSize::try_from(prefix.len()).unwrap();
+    let mut is_codeblock = false;
+    let mut is_doctest = false;
+    // Replace the original, line-spanning comment ranges by new, only comment-prefix
+    // spanning comment ranges.
+    let mut new_comments = Vec::new();
+    let doctest = node
+        .children_with_tokens()
+        .filter_map(|el| el.into_token().and_then(ast::Comment::cast))
+        .filter(|comment| comment.kind().doc.is_some())
+        .filter(|comment| {
+            if let Some(idx) = comment.text().find(RUSTDOC_FENCE) {
+                is_codeblock = !is_codeblock;
+                // Check whether code is rust by inspecting fence guards
+                let guards = &comment.text()[idx + RUSTDOC_FENCE.len()..];
+                let is_rust =
+                    guards.split(',').all(|sub| RUSTDOC_FENCE_TOKENS.contains(&sub.trim()));
+                is_doctest = is_codeblock && is_rust;
+                false
+            } else {
+                is_doctest
+            }
+        })
+        .map(|comment| {
+            let prefix_len = comment.prefix().len();
+            let line: &str = comment.text().as_str();
+            let range = comment.syntax().text_range();
+
+            // whitespace after comment is ignored
+            let pos = if let Some(ws) = line.chars().nth(prefix_len).filter(|c| c.is_whitespace()) {
+                prefix_len + ws.len_utf8()
+            } else {
+                prefix_len
+            };
+
+            // lines marked with `#` should be ignored in output, we skip the `#` char
+            let pos = if let Some(ws) = line.chars().nth(pos).filter(|&c| c == '#') {
+                pos + ws.len_utf8()
+            } else {
+                pos
+            };
+
+            range_mapping.insert(line_start, range.start() + TextSize::try_from(pos).unwrap());
+            new_comments.push(HighlightedRange {
+                range: TextRange::new(
+                    range.start(),
+                    range.start() + TextSize::try_from(pos).unwrap(),
+                ),
+                highlight: HighlightTag::Comment | HighlightModifier::Documentation,
+                binding_hash: None,
+            });
+            line_start += range.len() - TextSize::try_from(pos).unwrap();
+            line_start += TextSize::try_from('\n'.len_utf8()).unwrap();
+
+            line[pos..].to_owned()
+        })
+        .join("\n");
+
+    if doctest.is_empty() {
+        return None;
+    }
+
+    let doctest = format!("{}{}{}", prefix, doctest, suffix);
+    Some((doctest, range_mapping, new_comments))
+}
+
+/// Injection of syntax highlighting of doctests.
+pub(super) fn highlight_doc_comment(
+    text: String,
+    range_mapping: RangesMap,
+    new_comments: Vec<HighlightedRange>,
+    stack: &mut HighlightedRangeStack,
+) {
+    let (analysis, tmp_file_id) = Analysis::from_single_file(text);
+
+    stack.push();
+    for mut h in analysis.with_db(|db| super::highlight(db, tmp_file_id, None, true)).unwrap() {
+        // Determine start offset and end offset in case of multi-line ranges
+        let mut start_offset = None;
+        let mut end_offset = None;
+        for (line_start, orig_line_start) in range_mapping.range(..h.range.end()).rev() {
+            // It's possible for orig_line_start - line_start to be negative. Add h.range.start()
+            // here and remove it from the end range after the loop below so that the values are
+            // always non-negative.
+            let offset = h.range.start() + orig_line_start - line_start;
+            if line_start <= &h.range.start() {
+                start_offset.get_or_insert(offset);
+                break;
+            } else {
+                end_offset.get_or_insert(offset);
+            }
+        }
+        if let Some(start_offset) = start_offset {
+            h.range = TextRange::new(
+                start_offset,
+                h.range.end() + end_offset.unwrap_or(start_offset) - h.range.start(),
+            );
+
+            h.highlight |= HighlightModifier::Injected;
+            stack.add(h);
+        }
+    }
+
+    // Inject the comment prefix highlight ranges
+    stack.push();
+    for comment in new_comments {
+        stack.add(comment);
+    }
+    stack.pop_and_inject(None);
+    stack
+        .pop_and_inject(Some(Highlight::from(HighlightTag::Generic) | HighlightModifier::Injected));
+}
diff --git a/crates/ide/src/syntax_highlighting/tags.rs b/crates/ide/src/syntax_highlighting/tags.rs
new file mode 100644
index 000000000..49ec94bdc
--- /dev/null
+++ b/crates/ide/src/syntax_highlighting/tags.rs
@@ -0,0 +1,203 @@
+//! Defines token tags we use for syntax highlighting.
+//! A tag is not unlike a CSS class.
+
+use std::{fmt, ops};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct Highlight {
+    pub tag: HighlightTag,
+    pub modifiers: HighlightModifiers,
+}
+
+#[derive(Default, Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct HighlightModifiers(u32);
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub enum HighlightTag {
+    Attribute,
+    BoolLiteral,
+    BuiltinType,
+    ByteLiteral,
+    CharLiteral,
+    Comment,
+    Constant,
+    Enum,
+    EnumVariant,
+    EscapeSequence,
+    Field,
+    Function,
+    Generic,
+    Keyword,
+    Lifetime,
+    Macro,
+    Module,
+    NumericLiteral,
+    Punctuation,
+    SelfKeyword,
+    SelfType,
+    Static,
+    StringLiteral,
+    Struct,
+    Trait,
+    TypeAlias,
+    TypeParam,
+    Union,
+    ValueParam,
+    Local,
+    UnresolvedReference,
+    FormatSpecifier,
+    Operator,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[repr(u8)]
+pub enum HighlightModifier {
+    /// Used to differentiate individual elements within attributes.
+    Attribute = 0,
+    /// Used with keywords like `if` and `break`.
+    ControlFlow,
+    /// `foo` in `fn foo(x: i32)` is a definition, `foo` in `foo(90 + 2)` is
+    /// not.
+    Definition,
+    Documentation,
+    Injected,
+    Mutable,
+    Unsafe,
+}
+
+impl HighlightTag {
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightTag::Attribute => "attribute",
+            HighlightTag::BoolLiteral => "bool_literal",
+            HighlightTag::BuiltinType => "builtin_type",
+            HighlightTag::ByteLiteral => "byte_literal",
+            HighlightTag::CharLiteral => "char_literal",
+            HighlightTag::Comment => "comment",
+            HighlightTag::Constant => "constant",
+            HighlightTag::Enum => "enum",
+            HighlightTag::EnumVariant => "enum_variant",
+            HighlightTag::EscapeSequence => "escape_sequence",
+            HighlightTag::Field => "field",
+            HighlightTag::FormatSpecifier => "format_specifier",
+            HighlightTag::Function => "function",
+            HighlightTag::Generic => "generic",
+            HighlightTag::Keyword => "keyword",
+            HighlightTag::Lifetime => "lifetime",
+            HighlightTag::Punctuation => "punctuation",
+            HighlightTag::Macro => "macro",
+            HighlightTag::Module => "module",
+            HighlightTag::NumericLiteral => "numeric_literal",
+            HighlightTag::Operator => "operator",
+            HighlightTag::SelfKeyword => "self_keyword",
+            HighlightTag::SelfType => "self_type",
+            HighlightTag::Static => "static",
+            HighlightTag::StringLiteral => "string_literal",
+            HighlightTag::Struct => "struct",
+            HighlightTag::Trait => "trait",
+            HighlightTag::TypeAlias => "type_alias",
+            HighlightTag::TypeParam => "type_param",
+            HighlightTag::Union => "union",
+            HighlightTag::ValueParam => "value_param",
+            HighlightTag::Local => "variable",
+            HighlightTag::UnresolvedReference => "unresolved_reference",
+        }
+    }
+}
+
+impl fmt::Display for HighlightTag {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_str(), f)
+    }
+}
+
+impl HighlightModifier {
+    const ALL: &'static [HighlightModifier] = &[
+        HighlightModifier::Attribute,
+        HighlightModifier::ControlFlow,
+        HighlightModifier::Definition,
+        HighlightModifier::Documentation,
+        HighlightModifier::Injected,
+        HighlightModifier::Mutable,
+        HighlightModifier::Unsafe,
+    ];
+
+    fn as_str(self) -> &'static str {
+        match self {
+            HighlightModifier::Attribute => "attribute",
+            HighlightModifier::ControlFlow => "control",
+            HighlightModifier::Definition => "declaration",
+            HighlightModifier::Documentation => "documentation",
+            HighlightModifier::Injected => "injected",
+            HighlightModifier::Mutable => "mutable",
+            HighlightModifier::Unsafe => "unsafe",
+        }
+    }
+
+    fn mask(self) -> u32 {
+        1 << (self as u32)
+    }
+}
+
+impl fmt::Display for HighlightModifier {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self.as_str(), f)
+    }
+}
+
+impl fmt::Display for Highlight {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.tag)?;
+        for modifier in self.modifiers.iter() {
+            write!(f, ".{}", modifier)?
+        }
+        Ok(())
+    }
+}
+
+impl From<HighlightTag> for Highlight {
+    fn from(tag: HighlightTag) -> Highlight {
+        Highlight::new(tag)
+    }
+}
+
+impl Highlight {
+    pub(crate) fn new(tag: HighlightTag) -> Highlight {
+        Highlight { tag, modifiers: HighlightModifiers::default() }
+    }
+}
+
+impl ops::BitOr<HighlightModifier> for HighlightTag {
+    type Output = Highlight;
+
+    fn bitor(self, rhs: HighlightModifier) -> Highlight {
+        Highlight::new(self) | rhs
+    }
+}
+
+impl ops::BitOrAssign<HighlightModifier> for HighlightModifiers {
+    fn bitor_assign(&mut self, rhs: HighlightModifier) {
+        self.0 |= rhs.mask();
+    }
+}
+
+impl ops::BitOrAssign<HighlightModifier> for Highlight {
+    fn bitor_assign(&mut self, rhs: HighlightModifier) {
+        self.modifiers |= rhs;
+    }
+}
+
+impl ops::BitOr<HighlightModifier> for Highlight {
+    type Output = Highlight;
+
+    fn bitor(mut self, rhs: HighlightModifier) -> Highlight {
+        self |= rhs;
+        self
+    }
+}
+
+impl HighlightModifiers {
+    pub fn iter(self) -> impl Iterator<Item = HighlightModifier> {
+        HighlightModifier::ALL.iter().copied().filter(move |it| self.0 & it.mask() == it.mask())
+    }
+}
diff --git a/crates/ide/src/syntax_highlighting/tests.rs b/crates/ide/src/syntax_highlighting/tests.rs
new file mode 100644
index 000000000..94f37d773
--- /dev/null
+++ b/crates/ide/src/syntax_highlighting/tests.rs
@@ -0,0 +1,445 @@
+use std::fs;
+
+use expect::{expect_file, ExpectFile};
+use test_utils::project_dir;
+
+use crate::{mock_analysis::single_file, FileRange, TextRange};
+
+#[test]
+fn test_highlighting() {
+    check_highlighting(
+        r#"
+use inner::{self as inner_mod};
+mod inner {}
+
+#[derive(Clone, Debug)]
+struct Foo {
+    pub x: i32,
+    pub y: i32,
+}
+
+trait Bar {
+    fn bar(&self) -> i32;
+}
+
+impl Bar for Foo {
+    fn bar(&self) -> i32 {
+        self.x
+    }
+}
+
+impl Foo {
+    fn baz(mut self) -> i32 {
+        self.x
+    }
+
+    fn qux(&mut self) {
+        self.x = 0;
+    }
+}
+
+static mut STATIC_MUT: i32 = 0;
+
+fn foo<'a, T>() -> T {
+    foo::<'a, i32>()
+}
+
+macro_rules! def_fn {
+    ($($tt:tt)*) => {$($tt)*}
+}
+
+def_fn! {
+    fn bar() -> u32 {
+        100
+    }
+}
+
+macro_rules! noop {
+    ($expr:expr) => {
+        $expr
+    }
+}
+
+// comment
+fn main() {
+    println!("Hello, {}!", 92);
+
+    let mut vec = Vec::new();
+    if true {
+        let x = 92;
+        vec.push(Foo { x, y: 1 });
+    }
+    unsafe {
+        vec.set_len(0);
+        STATIC_MUT = 1;
+    }
+
+    for e in vec {
+        // Do nothing
+    }
+
+    noop!(noop!(1));
+
+    let mut x = 42;
+    let y = &mut x;
+    let z = &y;
+
+    let Foo { x: z, y } = Foo { x: z, y };
+
+    y;
+}
+
+enum Option<T> {
+    Some(T),
+    None,
+}
+use Option::*;
+
+impl<T> Option<T> {
+    fn and<U>(self, other: Option<U>) -> Option<(T, U)> {
+        match other {
+            None => unimplemented!(),
+            Nope => Nope,
+        }
+    }
+}
+"#
+        .trim(),
+        expect_file!["crates/ide/test_data/highlighting.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_rainbow_highlighting() {
+    check_highlighting(
+        r#"
+fn main() {
+    let hello = "hello";
+    let x = hello.to_string();
+    let y = hello.to_string();
+
+    let x = "other color please!";
+    let y = x.to_string();
+}
+
+fn bar() {
+    let mut hello = "hello";
+}
+"#
+        .trim(),
+        expect_file!["crates/ide/test_data/rainbow_highlighting.html"],
+        true,
+    );
+}
+
+#[test]
+fn accidentally_quadratic() {
+    let file = project_dir().join("crates/syntax/test_data/accidentally_quadratic");
+    let src = fs::read_to_string(file).unwrap();
+
+    let (analysis, file_id) = single_file(&src);
+
+    // let t = std::time::Instant::now();
+    let _ = analysis.highlight(file_id).unwrap();
+    // eprintln!("elapsed: {:?}", t.elapsed());
+}
+
+#[test]
+fn test_ranges() {
+    let (analysis, file_id) = single_file(
+        r#"
+#[derive(Clone, Debug)]
+struct Foo {
+    pub x: i32,
+    pub y: i32,
+}
+"#,
+    );
+
+    // The "x"
+    let highlights = &analysis
+        .highlight_range(FileRange { file_id, range: TextRange::at(45.into(), 1.into()) })
+        .unwrap();
+
+    assert_eq!(&highlights[0].highlight.to_string(), "field.declaration");
+}
+
+#[test]
+fn test_flattening() {
+    check_highlighting(
+        r##"
+fn fixture(ra_fixture: &str) {}
+
+fn main() {
+    fixture(r#"
+        trait Foo {
+            fn foo() {
+                println!("2 + 2 = {}", 4);
+            }
+        }"#
+    );
+}"##
+        .trim(),
+        expect_file!["crates/ide/test_data/highlight_injection.html"],
+        false,
+    );
+}
+
+#[test]
+fn ranges_sorted() {
+    let (analysis, file_id) = single_file(
+        r#"
+#[foo(bar = "bar")]
+macro_rules! test {}
+}"#
+        .trim(),
+    );
+    let _ = analysis.highlight(file_id).unwrap();
+}
+
+#[test]
+fn test_string_highlighting() {
+    // The format string detection is based on macro-expansion,
+    // thus, we have to copy the macro definition from `std`
+    check_highlighting(
+        r#"
+macro_rules! println {
+    ($($arg:tt)*) => ({
+        $crate::io::_print($crate::format_args_nl!($($arg)*));
+    })
+}
+#[rustc_builtin_macro]
+macro_rules! format_args_nl {
+    ($fmt:expr) => {{ /* compiler built-in */ }};
+    ($fmt:expr, $($args:tt)*) => {{ /* compiler built-in */ }};
+}
+
+fn main() {
+    // from https://doc.rust-lang.org/std/fmt/index.html
+    println!("Hello");                 // => "Hello"
+    println!("Hello, {}!", "world");   // => "Hello, world!"
+    println!("The number is {}", 1);   // => "The number is 1"
+    println!("{:?}", (3, 4));          // => "(3, 4)"
+    println!("{value}", value=4);      // => "4"
+    println!("{} {}", 1, 2);           // => "1 2"
+    println!("{:04}", 42);             // => "0042" with leading zerosV
+    println!("{1} {} {0} {}", 1, 2);   // => "2 1 1 2"
+    println!("{argument}", argument = "test");   // => "test"
+    println!("{name} {}", 1, name = 2);          // => "2 1"
+    println!("{a} {c} {b}", a="a", b='b', c=3);  // => "a 3 b"
+    println!("{{{}}}", 2);                       // => "{2}"
+    println!("Hello {:5}!", "x");
+    println!("Hello {:1$}!", "x", 5);
+    println!("Hello {1:0$}!", 5, "x");
+    println!("Hello {:width$}!", "x", width = 5);
+    println!("Hello {:<5}!", "x");
+    println!("Hello {:-<5}!", "x");
+    println!("Hello {:^5}!", "x");
+    println!("Hello {:>5}!", "x");
+    println!("Hello {:+}!", 5);
+    println!("{:#x}!", 27);
+    println!("Hello {:05}!", 5);
+    println!("Hello {:05}!", -5);
+    println!("{:#010x}!", 27);
+    println!("Hello {0} is {1:.5}", "x", 0.01);
+    println!("Hello {1} is {2:.0$}", 5, "x", 0.01);
+    println!("Hello {0} is {2:.1$}", "x", 5, 0.01);
+    println!("Hello {} is {:.*}",    "x", 5, 0.01);
+    println!("Hello {} is {2:.*}",   "x", 5, 0.01);
+    println!("Hello {} is {number:.prec$}", "x", prec = 5, number = 0.01);
+    println!("{}, `{name:.*}` has 3 fractional digits", "Hello", 3, name=1234.56);
+    println!("{}, `{name:.*}` has 3 characters", "Hello", 3, name="1234.56");
+    println!("{}, `{name:>8.*}` has 3 right-aligned characters", "Hello", 3, name="1234.56");
+    println!("Hello {{}}");
+    println!("{{ Hello");
+
+    println!(r"Hello, {}!", "world");
+
+    // escape sequences
+    println!("Hello\nWorld");
+    println!("\u{48}\x65\x6C\x6C\x6F World");
+
+    println!("{\x41}", A = 92);
+    println!("{ничоси}", ничоси = 92);
+}"#
+        .trim(),
+        expect_file!["crates/ide/test_data/highlight_strings.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_unsafe_highlighting() {
+    check_highlighting(
+        r#"
+unsafe fn unsafe_fn() {}
+
+union Union {
+    a: u32,
+    b: f32,
+}
+
+struct HasUnsafeFn;
+
+impl HasUnsafeFn {
+    unsafe fn unsafe_method(&self) {}
+}
+
+struct TypeForStaticMut {
+    a: u8
+}
+
+static mut global_mut: TypeForStaticMut = TypeForStaticMut { a: 0 };
+
+#[repr(packed)]
+struct Packed {
+    a: u16,
+}
+
+trait DoTheAutoref {
+    fn calls_autoref(&self);
+}
+
+impl DoTheAutoref for u16 {
+    fn calls_autoref(&self) {}
+}
+
+fn main() {
+    let x = &5 as *const _ as *const usize;
+    let u = Union { b: 0 };
+    unsafe {
+        // unsafe fn and method calls
+        unsafe_fn();
+        let b = u.b;
+        match u {
+            Union { b: 0 } => (),
+            Union { a } => (),
+        }
+        HasUnsafeFn.unsafe_method();
+
+        // unsafe deref
+        let y = *x;
+
+        // unsafe access to a static mut
+        let a = global_mut.a;
+
+        // unsafe ref of packed fields
+        let packed = Packed { a: 0 };
+        let a = &packed.a;
+        let ref a = packed.a;
+        let Packed { ref a } = packed;
+        let Packed { a: ref _a } = packed;
+
+        // unsafe auto ref of packed field
+        packed.a.calls_autoref();
+    }
+}
+"#
+        .trim(),
+        expect_file!["crates/ide/test_data/highlight_unsafe.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_highlight_doctest() {
+    check_highlighting(
+        r#"
+/// ```
+/// let _ = "early doctests should not go boom";
+/// ```
+struct Foo {
+    bar: bool,
+}
+
+impl Foo {
+    pub const bar: bool = true;
+
+    /// Constructs a new `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # #![allow(unused_mut)]
+    /// let mut foo: Foo = Foo::new();
+    /// ```
+    pub const fn new() -> Foo {
+        Foo { bar: true }
+    }
+
+    /// `bar` method on `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use x::y;
+    ///
+    /// let foo = Foo::new();
+    ///
+    /// // calls bar on foo
+    /// assert!(foo.bar());
+    ///
+    /// let bar = foo.bar || Foo::bar;
+    ///
+    /// /* multi-line
+    ///        comment */
+    ///
+    /// let multi_line_string = "Foo
+    ///   bar
+    ///          ";
+    ///
+    /// ```
+    ///
+    /// ```rust,no_run
+    /// let foobar = Foo::new().bar();
+    /// ```
+    ///
+    /// ```sh
+    /// echo 1
+    /// ```
+    pub fn foo(&self) -> bool {
+        true
+    }
+}
+
+/// ```
+/// noop!(1);
+/// ```
+macro_rules! noop {
+    ($expr:expr) => {
+        $expr
+    }
+}
+"#
+        .trim(),
+        expect_file!["crates/ide/test_data/highlight_doctest.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_extern_crate() {
+    check_highlighting(
+        r#"
+        //- /main.rs
+        extern crate std;
+        extern crate alloc as abc;
+        //- /std/lib.rs
+        pub struct S;
+        //- /alloc/lib.rs
+        pub struct A
+        "#,
+        expect_file!["crates/ide/test_data/highlight_extern_crate.html"],
+        false,
+    );
+}
+
+/// Highlights the code given by the `ra_fixture` argument, renders the
+/// result as HTML, and compares it with the HTML file given as `snapshot`.
+/// Note that the `snapshot` file is overwritten by the rendered HTML.
+fn check_highlighting(ra_fixture: &str, expect: ExpectFile, rainbow: bool) {
+    let (analysis, file_id) = single_file(ra_fixture);
+    let actual_html = &analysis.highlight_as_html(file_id, rainbow).unwrap();
+    expect.assert_eq(actual_html)
+}
diff --git a/crates/ide/src/syntax_tree.rs b/crates/ide/src/syntax_tree.rs
new file mode 100644
index 000000000..f80044959
--- /dev/null
+++ b/crates/ide/src/syntax_tree.rs
@@ -0,0 +1,359 @@
+use base_db::{FileId, SourceDatabase};
+use ide_db::RootDatabase;
+use syntax::{
+    algo, AstNode, NodeOrToken, SourceFile,
+    SyntaxKind::{RAW_STRING, STRING},
+    SyntaxToken, TextRange, TextSize,
+};
+
+// Feature: Show Syntax Tree
+//
+// Shows the parse tree of the current file. It exists mostly for debugging
+// rust-analyzer itself.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Show Syntax Tree**
+// |===
+pub(crate) fn syntax_tree(
+    db: &RootDatabase,
+    file_id: FileId,
+    text_range: Option<TextRange>,
+) -> String {
+    let parse = db.parse(file_id);
+    if let Some(text_range) = text_range {
+        let node = match algo::find_covering_element(parse.tree().syntax(), text_range) {
+            NodeOrToken::Node(node) => node,
+            NodeOrToken::Token(token) => {
+                if let Some(tree) = syntax_tree_for_string(&token, text_range) {
+                    return tree;
+                }
+                token.parent()
+            }
+        };
+
+        format!("{:#?}", node)
+    } else {
+        format!("{:#?}", parse.tree().syntax())
+    }
+}
+
+/// Attempts parsing the selected contents of a string literal
+/// as rust syntax and returns its syntax tree
+fn syntax_tree_for_string(token: &SyntaxToken, text_range: TextRange) -> Option<String> {
+    // When the range is inside a string
+    // we'll attempt parsing it as rust syntax
+    // to provide the syntax tree of the contents of the string
+    match token.kind() {
+        STRING | RAW_STRING => syntax_tree_for_token(token, text_range),
+        _ => None,
+    }
+}
+
+fn syntax_tree_for_token(node: &SyntaxToken, text_range: TextRange) -> Option<String> {
+    // Range of the full node
+    let node_range = node.text_range();
+    let text = node.text().to_string();
+
+    // We start at some point inside the node
+    // Either we have selected the whole string
+    // or our selection is inside it
+    let start = text_range.start() - node_range.start();
+
+    // how many characters we have selected
+    let len = text_range.len();
+
+    let node_len = node_range.len();
+
+    let start = start;
+
+    // We want to cap our length
+    let len = len.min(node_len);
+
+    // Ensure our slice is inside the actual string
+    let end =
+        if start + len < TextSize::of(&text) { start + len } else { TextSize::of(&text) - start };
+
+    let text = &text[TextRange::new(start, end)];
+
+    // Remove possible extra string quotes from the start
+    // and the end of the string
+    let text = text
+        .trim_start_matches('r')
+        .trim_start_matches('#')
+        .trim_start_matches('"')
+        .trim_end_matches('#')
+        .trim_end_matches('"')
+        .trim()
+        // Remove custom markers
+        .replace("<|>", "");
+
+    let parsed = SourceFile::parse(&text);
+
+    // If the "file" parsed without errors,
+    // return its syntax
+    if parsed.errors().is_empty() {
+        return Some(format!("{:#?}", parsed.tree().syntax()));
+    }
+
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use test_utils::assert_eq_text;
+
+    use crate::mock_analysis::{analysis_and_range, single_file};
+
+    #[test]
+    fn test_syntax_tree_without_range() {
+        // Basic syntax
+        let (analysis, file_id) = single_file(r#"fn foo() {}"#);
+        let syn = analysis.syntax_tree(file_id, None).unwrap();
+
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "}"
+"#
+            .trim()
+        );
+
+        let (analysis, file_id) = single_file(
+            r#"
+fn test() {
+    assert!("
+    fn foo() {
+    }
+    ", "");
+}"#
+            .trim(),
+        );
+        let syn = analysis.syntax_tree(file_id, None).unwrap();
+
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "test"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n    "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "assert"
+          [email protected] "!"
+          [email protected]
+            [email protected] "("
+            [email protected] "\"\n    fn foo() {\n     ..."
+            [email protected] ","
+            [email protected] " "
+            [email protected] "\"\""
+            [email protected] ")"
+        [email protected] ";"
+      [email protected] "\n"
+      [email protected] "}"
+"#
+            .trim()
+        );
+    }
+
+    #[test]
+    fn test_syntax_tree_with_range() {
+        let (analysis, range) = analysis_and_range(r#"<|>fn foo() {}<|>"#.trim());
+        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
+
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected] "fn"
+  [email protected] " "
+  [email protected]
+    [email protected] "foo"
+  [email protected]
+    [email protected] "("
+    [email protected] ")"
+  [email protected] " "
+  [email protected]
+    [email protected] "{"
+    [email protected] "}"
+"#
+            .trim()
+        );
+
+        let (analysis, range) = analysis_and_range(
+            r#"fn test() {
+    <|>assert!("
+    fn foo() {
+    }
+    ", "");<|>
+}"#
+            .trim(),
+        );
+        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
+
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected] "assert"
+    [email protected] "!"
+    [email protected]
+      [email protected] "("
+      [email protected] "\"\n    fn foo() {\n     ..."
+      [email protected] ","
+      [email protected] " "
+      [email protected] "\"\""
+      [email protected] ")"
+  [email protected] ";"
+"#
+            .trim()
+        );
+    }
+
+    #[test]
+    fn test_syntax_tree_inside_string() {
+        let (analysis, range) = analysis_and_range(
+            r#"fn test() {
+    assert!("
+<|>fn foo() {
+}<|>
+fn bar() {
+}
+    ", "");
+}"#
+            .trim(),
+        );
+        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+"#
+            .trim()
+        );
+
+        // With a raw string
+        let (analysis, range) = analysis_and_range(
+            r###"fn test() {
+    assert!(r#"
+<|>fn foo() {
+}<|>
+fn bar() {
+}
+    "#, "");
+}"###
+                .trim(),
+        );
+        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+"#
+            .trim()
+        );
+
+        // With a raw string
+        let (analysis, range) = analysis_and_range(
+            r###"fn test() {
+    assert!(r<|>#"
+fn foo() {
+}
+fn bar() {
+}"<|>#, "");
+}"###
+                .trim(),
+        );
+        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
+        assert_eq_text!(
+            syn.trim(),
+            r#"
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "bar"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+"#
+            .trim()
+        );
+    }
+}
diff --git a/crates/ide/src/typing.rs b/crates/ide/src/typing.rs
new file mode 100644
index 000000000..899ce5f26
--- /dev/null
+++ b/crates/ide/src/typing.rs
@@ -0,0 +1,364 @@
+//! This module handles auto-magic editing actions applied together with users
+//! edits. For example, if the user typed
+//!
+//! ```text
+//!     foo
+//!         .bar()
+//!         .baz()
+//!     |   // <- cursor is here
+//! ```
+//!
+//! and types `.` next, we want to indent the dot.
+//!
+//! Language server executes such typing assists synchronously. That is, they
+//! block user's typing and should be pretty fast for this reason!
+
+mod on_enter;
+
+use base_db::{FilePosition, SourceDatabase};
+use ide_db::{source_change::SourceFileEdit, RootDatabase};
+use syntax::{
+    algo::find_node_at_offset,
+    ast::{self, edit::IndentLevel, AstToken},
+    AstNode, SourceFile,
+    SyntaxKind::{FIELD_EXPR, METHOD_CALL_EXPR},
+    TextRange, TextSize,
+};
+
+use text_edit::TextEdit;
+
+use crate::SourceChange;
+
+pub(crate) use on_enter::on_enter;
+
+pub(crate) const TRIGGER_CHARS: &str = ".=>";
+
+// Feature: On Typing Assists
+//
+// Some features trigger on typing certain characters:
+//
+// - typing `let =` tries to smartly add `;` if `=` is followed by an existing expression
+// - typing `.` in a chain method call auto-indents
+pub(crate) fn on_char_typed(
+    db: &RootDatabase,
+    position: FilePosition,
+    char_typed: char,
+) -> Option<SourceChange> {
+    assert!(TRIGGER_CHARS.contains(char_typed));
+    let file = &db.parse(position.file_id).tree();
+    assert_eq!(file.syntax().text().char_at(position.offset), Some(char_typed));
+    let edit = on_char_typed_inner(file, position.offset, char_typed)?;
+    Some(SourceFileEdit { file_id: position.file_id, edit }.into())
+}
+
+fn on_char_typed_inner(file: &SourceFile, offset: TextSize, char_typed: char) -> Option<TextEdit> {
+    assert!(TRIGGER_CHARS.contains(char_typed));
+    match char_typed {
+        '.' => on_dot_typed(file, offset),
+        '=' => on_eq_typed(file, offset),
+        '>' => on_arrow_typed(file, offset),
+        _ => unreachable!(),
+    }
+}
+
+/// Returns an edit which should be applied after `=` was typed. Primarily,
+/// this works when adding `let =`.
+// FIXME: use a snippet completion instead of this hack here.
+fn on_eq_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
+    assert_eq!(file.syntax().text().char_at(offset), Some('='));
+    let let_stmt: ast::LetStmt = find_node_at_offset(file.syntax(), offset)?;
+    if let_stmt.semicolon_token().is_some() {
+        return None;
+    }
+    if let Some(expr) = let_stmt.initializer() {
+        let expr_range = expr.syntax().text_range();
+        if expr_range.contains(offset) && offset != expr_range.start() {
+            return None;
+        }
+        if file.syntax().text().slice(offset..expr_range.start()).contains_char('\n') {
+            return None;
+        }
+    } else {
+        return None;
+    }
+    let offset = let_stmt.syntax().text_range().end();
+    Some(TextEdit::insert(offset, ";".to_string()))
+}
+
+/// Returns an edit which should be applied when a dot ('.') is typed on a blank line, indenting the line appropriately.
+fn on_dot_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
+    assert_eq!(file.syntax().text().char_at(offset), Some('.'));
+    let whitespace =
+        file.syntax().token_at_offset(offset).left_biased().and_then(ast::Whitespace::cast)?;
+
+    let current_indent = {
+        let text = whitespace.text();
+        let newline = text.rfind('\n')?;
+        &text[newline + 1..]
+    };
+    let current_indent_len = TextSize::of(current_indent);
+
+    let parent = whitespace.syntax().parent();
+    // Make sure dot is a part of call chain
+    if !matches!(parent.kind(), FIELD_EXPR | METHOD_CALL_EXPR) {
+        return None;
+    }
+    let prev_indent = IndentLevel::from_node(&parent);
+    let target_indent = format!("    {}", prev_indent);
+    let target_indent_len = TextSize::of(&target_indent);
+    if current_indent_len == target_indent_len {
+        return None;
+    }
+
+    Some(TextEdit::replace(TextRange::new(offset - current_indent_len, offset), target_indent))
+}
+
+/// Adds a space after an arrow when `fn foo() { ... }` is turned into `fn foo() -> { ... }`
+fn on_arrow_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
+    let file_text = file.syntax().text();
+    assert_eq!(file_text.char_at(offset), Some('>'));
+    let after_arrow = offset + TextSize::of('>');
+    if file_text.char_at(after_arrow) != Some('{') {
+        return None;
+    }
+    if find_node_at_offset::<ast::RetType>(file.syntax(), offset).is_none() {
+        return None;
+    }
+
+    Some(TextEdit::insert(after_arrow, " ".to_string()))
+}
+
+#[cfg(test)]
+mod tests {
+    use test_utils::{assert_eq_text, extract_offset};
+
+    use super::*;
+
+    fn do_type_char(char_typed: char, before: &str) -> Option<String> {
+        let (offset, before) = extract_offset(before);
+        let edit = TextEdit::insert(offset, char_typed.to_string());
+        let mut before = before.to_string();
+        edit.apply(&mut before);
+        let parse = SourceFile::parse(&before);
+        on_char_typed_inner(&parse.tree(), offset, char_typed).map(|it| {
+            it.apply(&mut before);
+            before.to_string()
+        })
+    }
+
+    fn type_char(char_typed: char, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let actual = do_type_char(char_typed, ra_fixture_before)
+            .unwrap_or_else(|| panic!("typing `{}` did nothing", char_typed));
+
+        assert_eq_text!(ra_fixture_after, &actual);
+    }
+
+    fn type_char_noop(char_typed: char, before: &str) {
+        let file_change = do_type_char(char_typed, before);
+        assert!(file_change.is_none())
+    }
+
+    #[test]
+    fn test_on_eq_typed() {
+        //     do_check(r"
+        // fn foo() {
+        //     let foo =<|>
+        // }
+        // ", r"
+        // fn foo() {
+        //     let foo =;
+        // }
+        // ");
+        type_char(
+            '=',
+            r"
+fn foo() {
+    let foo <|> 1 + 1
+}
+",
+            r"
+fn foo() {
+    let foo = 1 + 1;
+}
+",
+        );
+        //     do_check(r"
+        // fn foo() {
+        //     let foo =<|>
+        //     let bar = 1;
+        // }
+        // ", r"
+        // fn foo() {
+        //     let foo =;
+        //     let bar = 1;
+        // }
+        // ");
+    }
+
+    #[test]
+    fn indents_new_chain_call() {
+        type_char(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                <|>
+            }
+            ",
+            r"
+            fn main() {
+                xs.foo()
+                    .
+            }
+            ",
+        );
+        type_char_noop(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                    <|>
+            }
+            ",
+        )
+    }
+
+    #[test]
+    fn indents_new_chain_call_with_semi() {
+        type_char(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                <|>;
+            }
+            ",
+            r"
+            fn main() {
+                xs.foo()
+                    .;
+            }
+            ",
+        );
+        type_char_noop(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                    <|>;
+            }
+            ",
+        )
+    }
+
+    #[test]
+    fn indents_new_chain_call_with_let() {
+        type_char(
+            '.',
+            r#"
+fn main() {
+    let _ = foo
+    <|>
+    bar()
+}
+"#,
+            r#"
+fn main() {
+    let _ = foo
+        .
+    bar()
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn indents_continued_chain_call() {
+        type_char(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                    .first()
+                <|>
+            }
+            ",
+            r"
+            fn main() {
+                xs.foo()
+                    .first()
+                    .
+            }
+            ",
+        );
+        type_char_noop(
+            '.',
+            r"
+            fn main() {
+                xs.foo()
+                    .first()
+                    <|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn indents_middle_of_chain_call() {
+        type_char(
+            '.',
+            r"
+            fn source_impl() {
+                let var = enum_defvariant_list().unwrap()
+                <|>
+                    .nth(92)
+                    .unwrap();
+            }
+            ",
+            r"
+            fn source_impl() {
+                let var = enum_defvariant_list().unwrap()
+                    .
+                    .nth(92)
+                    .unwrap();
+            }
+            ",
+        );
+        type_char_noop(
+            '.',
+            r"
+            fn source_impl() {
+                let var = enum_defvariant_list().unwrap()
+                    <|>
+                    .nth(92)
+                    .unwrap();
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn dont_indent_freestanding_dot() {
+        type_char_noop(
+            '.',
+            r"
+            fn main() {
+                <|>
+            }
+            ",
+        );
+        type_char_noop(
+            '.',
+            r"
+            fn main() {
+            <|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn adds_space_after_return_type() {
+        type_char('>', "fn foo() -<|>{ 92 }", "fn foo() -> { 92 }")
+    }
+}
diff --git a/crates/ide/src/typing/on_enter.rs b/crates/ide/src/typing/on_enter.rs
new file mode 100644
index 000000000..f7d46146c
--- /dev/null
+++ b/crates/ide/src/typing/on_enter.rs
@@ -0,0 +1,256 @@
+//! Handles the `Enter` key press. At the momently, this only continues
+//! comments, but should handle indent some time in the future as well.
+
+use base_db::{FilePosition, SourceDatabase};
+use ide_db::RootDatabase;
+use syntax::{
+    ast::{self, AstToken},
+    AstNode, SmolStr, SourceFile,
+    SyntaxKind::*,
+    SyntaxToken, TextRange, TextSize, TokenAtOffset,
+};
+use test_utils::mark;
+use text_edit::TextEdit;
+
+// Feature: On Enter
+//
+// rust-analyzer can override kbd:[Enter] key to make it smarter:
+//
+// - kbd:[Enter] inside triple-slash comments automatically inserts `///`
+// - kbd:[Enter] in the middle or after a trailing space in `//` inserts `//`
+//
+// This action needs to be assigned to shortcut explicitly.
+//
+// VS Code::
+//
+// Add the following to `keybindings.json`:
+// [source,json]
+// ----
+// {
+//   "key": "Enter",
+//   "command": "rust-analyzer.onEnter",
+//   "when": "editorTextFocus && !suggestWidgetVisible && editorLangId == rust"
+// }
+// ----
+pub(crate) fn on_enter(db: &RootDatabase, position: FilePosition) -> Option<TextEdit> {
+    let parse = db.parse(position.file_id);
+    let file = parse.tree();
+    let comment = file
+        .syntax()
+        .token_at_offset(position.offset)
+        .left_biased()
+        .and_then(ast::Comment::cast)?;
+
+    if comment.kind().shape.is_block() {
+        return None;
+    }
+
+    let prefix = comment.prefix();
+    let comment_range = comment.syntax().text_range();
+    if position.offset < comment_range.start() + TextSize::of(prefix) {
+        return None;
+    }
+
+    let mut remove_last_space = false;
+    // Continuing single-line non-doc comments (like this one :) ) is annoying
+    if prefix == "//" && comment_range.end() == position.offset {
+        if comment.text().ends_with(' ') {
+            mark::hit!(continues_end_of_line_comment_with_space);
+            remove_last_space = true;
+        } else if !followed_by_comment(&comment) {
+            return None;
+        }
+    }
+
+    let indent = node_indent(&file, comment.syntax())?;
+    let inserted = format!("\n{}{} $0", indent, prefix);
+    let delete = if remove_last_space {
+        TextRange::new(position.offset - TextSize::of(' '), position.offset)
+    } else {
+        TextRange::empty(position.offset)
+    };
+    let edit = TextEdit::replace(delete, inserted);
+    Some(edit)
+}
+
+fn followed_by_comment(comment: &ast::Comment) -> bool {
+    let ws = match comment.syntax().next_token().and_then(ast::Whitespace::cast) {
+        Some(it) => it,
+        None => return false,
+    };
+    if ws.spans_multiple_lines() {
+        return false;
+    }
+    ws.syntax().next_token().and_then(ast::Comment::cast).is_some()
+}
+
+fn node_indent(file: &SourceFile, token: &SyntaxToken) -> Option<SmolStr> {
+    let ws = match file.syntax().token_at_offset(token.text_range().start()) {
+        TokenAtOffset::Between(l, r) => {
+            assert!(r == *token);
+            l
+        }
+        TokenAtOffset::Single(n) => {
+            assert!(n == *token);
+            return Some("".into());
+        }
+        TokenAtOffset::None => unreachable!(),
+    };
+    if ws.kind() != WHITESPACE {
+        return None;
+    }
+    let text = ws.text();
+    let pos = text.rfind('\n').map(|it| it + 1).unwrap_or(0);
+    Some(text[pos..].into())
+}
+
+#[cfg(test)]
+mod tests {
+    use stdx::trim_indent;
+    use test_utils::{assert_eq_text, mark};
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn apply_on_enter(before: &str) -> Option<String> {
+        let (analysis, position) = analysis_and_position(&before);
+        let result = analysis.on_enter(position).unwrap()?;
+
+        let mut actual = analysis.file_text(position.file_id).unwrap().to_string();
+        result.apply(&mut actual);
+        Some(actual)
+    }
+
+    fn do_check(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let actual = apply_on_enter(ra_fixture_before).unwrap();
+        assert_eq_text!(ra_fixture_after, &actual);
+    }
+
+    fn do_check_noop(ra_fixture_text: &str) {
+        assert!(apply_on_enter(ra_fixture_text).is_none())
+    }
+
+    #[test]
+    fn continues_doc_comment() {
+        do_check(
+            r"
+/// Some docs<|>
+fn foo() {
+}
+",
+            r"
+/// Some docs
+/// $0
+fn foo() {
+}
+",
+        );
+
+        do_check(
+            r"
+impl S {
+    /// Some<|> docs.
+    fn foo() {}
+}
+",
+            r"
+impl S {
+    /// Some
+    /// $0 docs.
+    fn foo() {}
+}
+",
+        );
+
+        do_check(
+            r"
+///<|> Some docs
+fn foo() {
+}
+",
+            r"
+///
+/// $0 Some docs
+fn foo() {
+}
+",
+        );
+    }
+
+    #[test]
+    fn does_not_continue_before_doc_comment() {
+        do_check_noop(r"<|>//! docz");
+    }
+
+    #[test]
+    fn continues_code_comment_in_the_middle_of_line() {
+        do_check(
+            r"
+fn main() {
+    // Fix<|> me
+    let x = 1 + 1;
+}
+",
+            r"
+fn main() {
+    // Fix
+    // $0 me
+    let x = 1 + 1;
+}
+",
+        );
+    }
+
+    #[test]
+    fn continues_code_comment_in_the_middle_several_lines() {
+        do_check(
+            r"
+fn main() {
+    // Fix<|>
+    // me
+    let x = 1 + 1;
+}
+",
+            r"
+fn main() {
+    // Fix
+    // $0
+    // me
+    let x = 1 + 1;
+}
+",
+        );
+    }
+
+    #[test]
+    fn does_not_continue_end_of_line_comment() {
+        do_check_noop(
+            r"
+fn main() {
+    // Fix me<|>
+    let x = 1 + 1;
+}
+",
+        );
+    }
+
+    #[test]
+    fn continues_end_of_line_comment_with_space() {
+        mark::check!(continues_end_of_line_comment_with_space);
+        do_check(
+            r#"
+fn main() {
+    // Fix me <|>
+    let x = 1 + 1;
+}
+"#,
+            r#"
+fn main() {
+    // Fix me
+    // $0
+    let x = 1 + 1;
+}
+"#,
+        );
+    }
+}