10 files changed, 736 insertions, 89 deletions

diff --git a/crates/ra_ide/src/completion/complete_attribute.rs b/crates/ra_ide/src/completion/complete_attribute.rs
index 8bf952798..f17266221 100644
--- a/crates/ra_ide/src/completion/complete_attribute.rs
+++ b/crates/ra_ide/src/completion/complete_attribute.rs
@@ -3,25 +3,29 @@
 //! This module uses a bit of static metadata to provide completions
 //! for built-in attributes.
 
-use super::completion_context::CompletionContext;
-use super::completion_item::{CompletionItem, CompletionItemKind, CompletionKind, Completions};
-use ra_syntax::{
-    ast::{Attr, AttrKind},
-    AstNode,
+use ra_syntax::{ast, AstNode, SyntaxKind};
+use rustc_hash::FxHashSet;
+
+use crate::completion::{
+    completion_context::CompletionContext,
+    completion_item::{CompletionItem, CompletionItemKind, CompletionKind, Completions},
 };
 
-pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) {
-    if !ctx.is_attribute {
-        return;
-    }
+pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
+    let attribute = ctx.attribute_under_caret.as_ref()?;
 
-    let is_inner = ctx
-        .original_token
-        .ancestors()
-        .find_map(Attr::cast)
-        .map(|attr| attr.kind() == AttrKind::Inner)
-        .unwrap_or(false);
+    match (attribute.path(), attribute.input()) {
+        (Some(path), Some(ast::AttrInput::TokenTree(token_tree)))
+            if path.to_string() == "derive" =>
+        {
+            complete_derive(acc, ctx, 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,
@@ -37,7 +41,7 @@ pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext)
             _ => {}
         }
 
-        if is_inner || !attr_completion.should_be_inner {
+        if attribute.kind() == ast::AttrKind::Inner || !attr_completion.should_be_inner {
             acc.add(item);
         }
     }
@@ -126,6 +130,106 @@ const ATTRIBUTES: &[AttrCompletion] = &[
     },
 ];
 
+fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
+    if let Ok(existing_derives) = parse_derive_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 parse_derive_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)
+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"] },
+];
+
 #[cfg(test)]
 mod tests {
     use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
@@ -136,6 +240,170 @@ mod tests {
     }
 
     #[test]
+    fn empty_derive_completion() {
+        assert_debug_snapshot!(
+            do_attr_completion(
+                    r"
+                    #[derive(<|>)]
+                    struct Test {}
+                    ",
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "Clone",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Clone",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Copy, Clone",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Copy, Clone",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Debug",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Debug",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Default",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Default",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Eq, PartialEq",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Eq, PartialEq",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Hash",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Hash",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Ord, PartialOrd, Eq, PartialEq",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "Ord, PartialOrd, Eq, PartialEq",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "PartialEq",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "PartialEq",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "PartialOrd, PartialEq",
+                source_range: 30..30,
+                delete: 30..30,
+                insert: "PartialOrd, PartialEq",
+                kind: Attribute,
+            },
+        ]
+            "###
+        );
+    }
+
+    #[test]
+    fn no_completion_for_incorrect_derive() {
+        assert_debug_snapshot!(
+            do_attr_completion(
+                r"
+                    #[derive{<|>)]
+                    struct Test {}
+                    ",
+            ),
+            @"[]"
+        );
+    }
+
+    #[test]
+    fn derive_with_input_completion() {
+        assert_debug_snapshot!(
+            do_attr_completion(
+                    r"
+                    #[derive(serde::Serialize, PartialEq, <|>)]
+                    struct Test {}
+                    ",
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "Clone",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Clone",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Copy, Clone",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Copy, Clone",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Debug",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Debug",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Default",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Default",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Eq",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Eq",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Hash",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Hash",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "Ord, PartialOrd, Eq",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "Ord, PartialOrd, Eq",
+                kind: Attribute,
+            },
+            CompletionItem {
+                label: "PartialOrd",
+                source_range: 59..59,
+                delete: 59..59,
+                insert: "PartialOrd",
+                kind: Attribute,
+            },
+        ]
+            "###
+        );
+    }
+
+    #[test]
     fn test_attribute_completion() {
         assert_debug_snapshot!(
         do_attr_completion(
diff --git a/crates/ra_ide/src/completion/complete_postfix.rs b/crates/ra_ide/src/completion/complete_postfix.rs
index 6a0f0c72e..f2a52a407 100644
--- a/crates/ra_ide/src/completion/complete_postfix.rs
+++ b/crates/ra_ide/src/completion/complete_postfix.rs
@@ -14,6 +14,7 @@ use crate::{
     },
     CompletionItem,
 };
+use ra_assists::utils::TryEnum;
 
 pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.config.enable_postfix_completions {
@@ -37,8 +38,53 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         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);
 
-    if receiver_ty.is_bool() || receiver_ty.is_unknown() {
+                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,
@@ -58,7 +104,6 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         )
         .add_to(acc);
     }
-
     // !&&&42 is a compiler error, ergo process it before considering the references
     postfix_snippet(ctx, cap, &dot_receiver, "not", "!expr", &format!("!{}", receiver_text))
         .add_to(acc);
@@ -80,16 +125,45 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     let dot_receiver = include_references(dot_receiver);
     let receiver_text =
         get_receiver_text(&dot_receiver, ctx.dot_receiver_is_ambiguous_float_literal);
-
-    postfix_snippet(
-        ctx,
-        cap,
-        &dot_receiver,
-        "match",
-        "match expr {}",
-        &format!("match {} {{\n    ${{1:_}} => {{$0\\}},\n}}", receiver_text),
-    )
-    .add_to(acc);
+    match try_enum {
+        Some(try_enum) => {
+            match try_enum {
+                TryEnum::Result => {
+                    postfix_snippet(
+                    ctx,
+                    cap,
+                    &dot_receiver,
+                    "match",
+                    "match expr {}",
+                    &format!("match {} {{\n    Ok(${{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,
@@ -236,6 +310,164 @@ mod tests {
     }
 
     #[test]
+    fn postfix_completion_works_for_option() {
+        assert_debug_snapshot!(
+            do_postfix_completion(
+                r#"
+                enum Option<T> {
+                    Some(T),
+                    None,
+                }
+
+                fn main() {
+                    let bar = Option::Some(true);
+                    bar.<|>
+                }
+                "#,
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "box",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "Box::new(bar)",
+                detail: "Box::new(expr)",
+            },
+            CompletionItem {
+                label: "dbg",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "dbg!(bar)",
+                detail: "dbg!(expr)",
+            },
+            CompletionItem {
+                label: "ifl",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "if let Some($1) = bar {\n    $0\n}",
+                detail: "if let Some {}",
+            },
+            CompletionItem {
+                label: "match",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "match bar {\n    Some(${1:_}) => {$2\\},\n    None => {$0\\},\n}",
+                detail: "match expr {}",
+            },
+            CompletionItem {
+                label: "not",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "!bar",
+                detail: "!expr",
+            },
+            CompletionItem {
+                label: "ref",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "&bar",
+                detail: "&expr",
+            },
+            CompletionItem {
+                label: "refm",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "&mut bar",
+                detail: "&mut expr",
+            },
+            CompletionItem {
+                label: "while",
+                source_range: 210..210,
+                delete: 206..210,
+                insert: "while let Some($1) = bar {\n    $0\n}",
+                detail: "while let Some {}",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn postfix_completion_works_for_result() {
+        assert_debug_snapshot!(
+            do_postfix_completion(
+                r#"
+                enum Result<T, E> {
+                    Ok(T),
+                    Err(E),
+                }
+
+                fn main() {
+                    let bar = Result::Ok(true);
+                    bar.<|>
+                }
+                "#,
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "box",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "Box::new(bar)",
+                detail: "Box::new(expr)",
+            },
+            CompletionItem {
+                label: "dbg",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "dbg!(bar)",
+                detail: "dbg!(expr)",
+            },
+            CompletionItem {
+                label: "ifl",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "if let Ok($1) = bar {\n    $0\n}",
+                detail: "if let Ok {}",
+            },
+            CompletionItem {
+                label: "match",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "match bar {\n    Ok(${1:_}) => {$2\\},\n    Err(${3:_}) => {$0\\},\n}",
+                detail: "match expr {}",
+            },
+            CompletionItem {
+                label: "not",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "!bar",
+                detail: "!expr",
+            },
+            CompletionItem {
+                label: "ref",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "&bar",
+                detail: "&expr",
+            },
+            CompletionItem {
+                label: "refm",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "&mut bar",
+                detail: "&mut expr",
+            },
+            CompletionItem {
+                label: "while",
+                source_range: 211..211,
+                delete: 207..211,
+                insert: "while let Ok($1) = bar {\n    $0\n}",
+                detail: "while let Ok {}",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
     fn some_postfix_completions_ignored() {
         assert_debug_snapshot!(
             do_postfix_completion(
diff --git a/crates/ra_ide/src/completion/complete_qualified_path.rs b/crates/ra_ide/src/completion/complete_qualified_path.rs
index aa56a5cd8..02ac0166b 100644
--- a/crates/ra_ide/src/completion/complete_qualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_qualified_path.rs
@@ -2,20 +2,25 @@
 
 use hir::{Adt, HasVisibility, PathResolution, ScopeDef};
 use ra_syntax::AstNode;
-use test_utils::tested_by;
+use rustc_hash::FxHashSet;
+use test_utils::mark;
 
 use crate::completion::{CompletionContext, Completions};
-use rustc_hash::FxHashSet;
 
 pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionContext) {
     let path = match &ctx.path_prefix {
         Some(path) => path.clone(),
-        _ => return,
+        None => return,
     };
+
+    if ctx.attribute_under_caret.is_some() {
+        return;
+    }
+
     let scope = ctx.scope();
     let context_module = scope.module();
 
-    let res = match scope.resolve_hir_path(&path) {
+    let res = match scope.resolve_hir_path_qualifier(&path) {
         Some(res) => res,
         None => return,
     };
@@ -35,7 +40,7 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                         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
-                                tested_by!(dont_complete_current_use);
+                                mark::hit!(dont_complete_current_use);
                                 continue;
                             }
                         }
@@ -79,7 +84,7 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                 });
 
                 // Iterate assoc types separately
-                ty.iterate_impl_items(ctx.db, krate, |item| {
+                ty.iterate_assoc_items(ctx.db, krate, |item| {
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
                         return None;
                     }
@@ -142,7 +147,7 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 
 #[cfg(test)]
 mod tests {
-    use test_utils::covers;
+    use test_utils::mark;
 
     use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
     use insta::assert_debug_snapshot;
@@ -153,7 +158,7 @@ mod tests {
 
     #[test]
     fn dont_complete_current_use() {
-        covers!(dont_complete_current_use);
+        mark::check!(dont_complete_current_use);
         let completions = do_completion(r"use self::foo<|>;", CompletionKind::Reference);
         assert!(completions.is_empty());
     }
@@ -221,6 +226,34 @@ mod tests {
     }
 
     #[test]
+    fn completes_mod_with_same_name_as_function() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r"
+                use self::my::<|>;
+
+                mod my {
+                    pub struct Bar;
+                }
+
+                fn my() {}
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "Bar",
+                source_range: 31..31,
+                delete: 31..31,
+                insert: "Bar",
+                kind: Struct,
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
     fn path_visibility() {
         assert_debug_snapshot!(
             do_reference_completion(
@@ -1325,4 +1358,18 @@ mod tests {
         "###
         );
     }
+
+    #[test]
+    fn dont_complete_attr() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r"
+                mod foo { pub struct Foo; }
+                #[foo::<|>]
+                fn f() {}
+                "
+            ),
+            @r###"[]"###
+        )
+    }
 }
diff --git a/crates/ra_ide/src/completion/complete_snippet.rs b/crates/ra_ide/src/completion/complete_snippet.rs
index a3f5d1b6a..0568d9ccf 100644
--- a/crates/ra_ide/src/completion/complete_snippet.rs
+++ b/crates/ra_ide/src/completion/complete_snippet.rs
@@ -36,6 +36,24 @@ pub(super) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionConte
     snippet(
         ctx,
         cap,
+        "Test module",
+        "\
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ${1:test_name}() {
+        $0
+    }
+}",
+    )
+    .lookup_by("tmod")
+    .add_to(acc);
+
+    snippet(
+        ctx,
+        cap,
         "Test function",
         "\
 #[test]
@@ -118,6 +136,14 @@ mod tests {
                 lookup: "tfn",
             },
             CompletionItem {
+                label: "Test module",
+                source_range: 78..78,
+                delete: 78..78,
+                insert: "#[cfg(test)]\nmod tests {\n    use super::*;\n\n    #[test]\n    fn ${1:test_name}() {\n        $0\n    }\n}",
+                kind: Snippet,
+                lookup: "tmod",
+            },
+            CompletionItem {
                 label: "macro_rules",
                 source_range: 78..78,
                 delete: 78..78,
diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index ee32d1ff6..039df03e0 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -32,7 +32,7 @@
 //! ```
 
 use hir::{self, Docs, HasSource};
-use ra_assists::utils::get_missing_impl_items;
+use ra_assists::utils::get_missing_assoc_items;
 use ra_syntax::{
     ast::{self, edit, ImplDef},
     AstNode, SyntaxKind, SyntaxNode, TextRange, T,
@@ -50,7 +50,7 @@ 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_impl_items(&ctx.sema, &impl_def).iter().for_each(|item| match item {
+                get_missing_assoc_items(&ctx.sema, &impl_def).iter().for_each(|item| match item {
                     hir::AssocItem::Function(fn_item) => {
                         add_function_impl(&trigger, acc, ctx, &fn_item)
                     }
@@ -64,34 +64,40 @@ pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext
             }
 
             SyntaxKind::FN_DEF => {
-                for missing_fn in get_missing_impl_items(&ctx.sema, &impl_def).iter().filter_map(
-                    |item| match item {
-                        hir::AssocItem::Function(fn_item) => Some(fn_item),
-                        _ => None,
-                    },
-                ) {
+                for missing_fn in
+                    get_missing_assoc_items(&ctx.sema, &impl_def).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_DEF => {
-                for missing_fn in get_missing_impl_items(&ctx.sema, &impl_def).iter().filter_map(
-                    |item| match item {
-                        hir::AssocItem::TypeAlias(type_item) => Some(type_item),
-                        _ => None,
-                    },
-                ) {
+                for missing_fn in
+                    get_missing_assoc_items(&ctx.sema, &impl_def).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_DEF => {
-                for missing_fn in get_missing_impl_items(&ctx.sema, &impl_def).iter().filter_map(
-                    |item| match item {
-                        hir::AssocItem::Const(const_item) => Some(const_item),
-                        _ => None,
-                    },
-                ) {
+                for missing_fn in
+                    get_missing_assoc_items(&ctx.sema, &impl_def).iter().filter_map(|item| {
+                        match item {
+                            hir::AssocItem::Const(const_item) => Some(const_item),
+                            _ => None,
+                        }
+                    })
+                {
                     add_const_impl(&trigger, acc, ctx, &missing_fn);
                 }
             }
diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index a6a5568de..db791660a 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -1,16 +1,19 @@
 //! Completion of names from the current scope, e.g. locals and imported items.
 
 use hir::ScopeDef;
-use test_utils::tested_by;
+use test_utils::mark;
 
 use crate::completion::{CompletionContext, Completions};
 use hir::{Adt, ModuleDef, Type};
 use ra_syntax::AstNode;
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
-    if (!ctx.is_trivial_path && !ctx.is_pat_binding_or_const)
-        || ctx.record_lit_syntax.is_some()
+    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;
     }
@@ -27,7 +30,7 @@ pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         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() {
-                    tested_by!(self_fulfilling_completion);
+                    mark::hit!(self_fulfilling_completion);
                     return;
                 }
             }
@@ -63,7 +66,7 @@ fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &T
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
-    use test_utils::covers;
+    use test_utils::mark;
 
     use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
 
@@ -73,7 +76,7 @@ mod tests {
 
     #[test]
     fn self_fulfilling_completion() {
-        covers!(self_fulfilling_completion);
+        mark::check!(self_fulfilling_completion);
         assert_debug_snapshot!(
             do_reference_completion(
                 r#"
@@ -1369,4 +1372,18 @@ mod tests {
         "###
         )
     }
+
+    #[test]
+    fn dont_complete_attr() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r"
+                struct Foo;
+                #[<|>]
+                fn f() {}
+                "
+            ),
+            @r###"[]"###
+        )
+    }
 }
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index 118fceb2e..da336973c 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -9,7 +9,7 @@ use ra_syntax::{
     SyntaxKind::*,
     SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
-use ra_text_edit::AtomTextEdit;
+use ra_text_edit::Indel;
 
 use crate::{call_info::ActiveParameter, completion::CompletionConfig, FilePosition};
 
@@ -34,7 +34,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) record_pat_syntax: Option<ast::RecordPat>,
     pub(super) record_field_syntax: Option<ast::RecordField>,
     pub(super) impl_def: Option<ast::ImplDef>,
-    /// FIXME: `ActiveParameter` is string-based, which is very wrong
+    /// 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.
@@ -58,7 +58,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) is_macro_call: bool,
     pub(super) is_path_type: bool,
     pub(super) has_type_args: bool,
-    pub(super) is_attribute: bool,
+    pub(super) attribute_under_caret: Option<ast::Attr>,
 }
 
 impl<'a> CompletionContext<'a> {
@@ -76,7 +76,7 @@ impl<'a> CompletionContext<'a> {
         // actual completion.
         let file_with_fake_ident = {
             let parse = db.parse(position.file_id);
-            let edit = AtomTextEdit::insert(position.offset, "intellijRulezz".to_string());
+            let edit = Indel::insert(position.offset, "intellijRulezz".to_string());
             parse.reparse(&edit).tree()
         };
         let fake_ident_token =
@@ -116,7 +116,7 @@ impl<'a> CompletionContext<'a> {
             is_path_type: false,
             has_type_args: false,
             dot_receiver_is_ambiguous_float_literal: false,
-            is_attribute: false,
+            attribute_under_caret: None,
         };
 
         let mut original_file = original_file.syntax().clone();
@@ -200,6 +200,7 @@ impl<'a> CompletionContext<'a> {
                 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) {
@@ -318,7 +319,6 @@ impl<'a> CompletionContext<'a> {
                 .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_attribute = path.syntax().parent().and_then(ast::Attr::cast).is_some();
 
             self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
             self.has_type_args = segment.type_arg_list().is_some();
@@ -344,7 +344,7 @@ impl<'a> CompletionContext<'a> {
                                 stmt.syntax().text_range() == name_ref.syntax().text_range(),
                             );
                         }
-                        if let Some(block) = ast::Block::cast(node) {
+                        if let Some(block) = ast::BlockExpr::cast(node) {
                             return Some(
                                 block.expr().map(|e| e.syntax().text_range())
                                     == Some(name_ref.syntax().text_range()),
diff --git a/crates/ra_ide/src/completion/completion_item.rs b/crates/ra_ide/src/completion/completion_item.rs
index 5936fb8f7..cfb7c1e38 100644
--- a/crates/ra_ide/src/completion/completion_item.rs
+++ b/crates/ra_ide/src/completion/completion_item.rs
@@ -2,11 +2,12 @@
 
 use std::fmt;
 
-use super::completion_config::SnippetCap;
 use hir::Documentation;
 use ra_syntax::TextRange;
 use ra_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.
@@ -62,8 +63,8 @@ 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().as_atoms().len() == 1 {
-            let atom = &self.text_edit().as_atoms()[0];
+        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 {
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 2edb130cf..440ffa31d 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -3,7 +3,7 @@
 use hir::{Docs, HasAttrs, HasSource, HirDisplay, ModPath, ScopeDef, StructKind, Type};
 use ra_syntax::ast::NameOwner;
 use stdx::SepBy;
-use test_utils::tested_by;
+use test_utils::mark;
 
 use crate::{
     completion::{
@@ -17,12 +17,11 @@ use crate::{
 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 ty = ty.display(ctx.db).to_string();
         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.clone())
+                .detail(ty.display(ctx.db).to_string())
                 .set_documentation(field.docs(ctx.db))
                 .set_deprecated(is_deprecated);
 
@@ -107,6 +106,12 @@ impl Completions {
             }
         };
 
+        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 {
@@ -116,7 +121,7 @@ impl Completions {
                     _ => false,
                 };
                 if has_non_default_type_params {
-                    tested_by!(inserts_angle_brackets_for_generics);
+                    mark::hit!(inserts_angle_brackets_for_generics);
                     completion_item = completion_item
                         .lookup_by(local_name.clone())
                         .label(format!("{}<…>", local_name))
@@ -171,7 +176,7 @@ impl Completions {
             }
             None if needs_bang => builder.insert_text(format!("{}!", name)),
             _ => {
-                tested_by!(dont_insert_macro_call_parens_unncessary);
+                mark::hit!(dont_insert_macro_call_parens_unncessary);
                 builder.insert_text(name)
             }
         };
@@ -319,19 +324,20 @@ impl Completions {
 
 pub(crate) fn compute_score(
     ctx: &CompletionContext,
-    // FIXME: this definitely should be a `Type`
-    ty: &str,
+    ty: &Type,
     name: &str,
 ) -> Option<CompletionScore> {
+    // FIXME: this should not fall back to string equality.
+    let ty = &ty.display(ctx.db).to_string();
     let (active_name, active_type) = if let Some(record_field) = &ctx.record_field_syntax {
-        tested_by!(test_struct_field_completion_in_record_lit);
+        mark::hit!(test_struct_field_completion_in_record_lit);
         let (struct_field, _local) = ctx.sema.resolve_record_field(record_field)?;
         (
             struct_field.name(ctx.db).to_string(),
             struct_field.signature_ty(ctx.db).display(ctx.db).to_string(),
         )
     } else if let Some(active_parameter) = &ctx.active_parameter {
-        tested_by!(test_struct_field_completion_in_func_call);
+        mark::hit!(test_struct_field_completion_in_func_call);
         (active_parameter.name.clone(), active_parameter.ty.clone())
     } else {
         return None;
@@ -392,7 +398,7 @@ impl Builder {
             None => return self,
         };
         // If not an import, add parenthesis automatically.
-        tested_by!(inserts_parens_for_function_calls);
+        mark::hit!(inserts_parens_for_function_calls);
 
         let (snippet, label) = if params.is_empty() {
             (format!("{}()$0", name), format!("{}()", name))
@@ -451,7 +457,7 @@ fn guess_macro_braces(macro_name: &str, docs: &str) -> (&'static str, &'static s
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
-    use test_utils::covers;
+    use test_utils::mark;
 
     use crate::completion::{
         test_utils::{do_completion, do_completion_with_options},
@@ -601,7 +607,7 @@ mod tests {
 
     #[test]
     fn inserts_parens_for_function_calls() {
-        covers!(inserts_parens_for_function_calls);
+        mark::check!(inserts_parens_for_function_calls);
         assert_debug_snapshot!(
             do_reference_completion(
                 r"
@@ -986,7 +992,7 @@ mod tests {
 
     #[test]
     fn inserts_angle_brackets_for_generics() {
-        covers!(inserts_angle_brackets_for_generics);
+        mark::check!(inserts_angle_brackets_for_generics);
         assert_debug_snapshot!(
             do_reference_completion(
                 r"
@@ -1109,7 +1115,7 @@ mod tests {
 
     #[test]
     fn dont_insert_macro_call_parens_unncessary() {
-        covers!(dont_insert_macro_call_parens_unncessary);
+        mark::check!(dont_insert_macro_call_parens_unncessary);
         assert_debug_snapshot!(
             do_reference_completion(
                 r"
@@ -1175,7 +1181,7 @@ mod tests {
 
     #[test]
     fn test_struct_field_completion_in_func_call() {
-        covers!(test_struct_field_completion_in_func_call);
+        mark::check!(test_struct_field_completion_in_func_call);
         assert_debug_snapshot!(
         do_reference_completion(
                 r"
@@ -1265,7 +1271,7 @@ mod tests {
 
     #[test]
     fn test_struct_field_completion_in_record_lit() {
-        covers!(test_struct_field_completion_in_record_lit);
+        mark::check!(test_struct_field_completion_in_record_lit);
         assert_debug_snapshot!(
         do_reference_completion(
                 r"
@@ -1405,4 +1411,48 @@ mod tests {
         "###
         );
     }
+
+    #[test]
+    fn prioritize_exact_ref_match() {
+        assert_debug_snapshot!(
+        do_reference_completion(
+                r"
+                    struct WorldSnapshot { _f: () };
+                    fn go(world: &WorldSnapshot) {
+                        go(w<|>)
+                    }
+                    ",
+        ),
+            @r###"
+        [
+            CompletionItem {
+                label: "WorldSnapshot",
+                source_range: 132..133,
+                delete: 132..133,
+                insert: "WorldSnapshot",
+                kind: Struct,
+            },
+            CompletionItem {
+                label: "go(…)",
+                source_range: 132..133,
+                delete: 132..133,
+                insert: "go(${1:world})$0",
+                kind: Function,
+                lookup: "go",
+                detail: "fn go(world: &WorldSnapshot)",
+                trigger_call_info: true,
+            },
+            CompletionItem {
+                label: "world",
+                source_range: 132..133,
+                delete: 132..133,
+                insert: "world",
+                kind: Binding,
+                detail: "&WorldSnapshot",
+                score: TypeAndNameMatch,
+            },
+        ]
+        "###
+        );
+    }
 }
diff --git a/crates/ra_ide/src/completion/test_utils.rs b/crates/ra_ide/src/completion/test_utils.rs
index eb90b5279..bf22452a2 100644
--- a/crates/ra_ide/src/completion/test_utils.rs
+++ b/crates/ra_ide/src/completion/test_utils.rs
@@ -20,7 +20,7 @@ pub(crate) fn do_completion_with_options(
     } else {
         single_file_with_position(code)
     };
-    let completions = analysis.completions(position, options).unwrap().unwrap();
+    let completions = analysis.completions(options, position).unwrap().unwrap();
     let completion_items: Vec<CompletionItem> = completions.into();
     let mut kind_completions: Vec<CompletionItem> =
         completion_items.into_iter().filter(|c| c.completion_kind == kind).collect();