102 files changed, 2148 insertions, 716 deletions

diff --git a/crates/assists/src/assist_context.rs b/crates/assists/src/assist_context.rs
index 69499ea32..4f59d39a9 100644
--- a/crates/assists/src/assist_context.rs
+++ b/crates/assists/src/assist_context.rs
@@ -4,10 +4,10 @@ use std::mem;
 
 use algo::find_covering_element;
 use hir::Semantics;
-use ide_db::base_db::{FileId, FileRange};
+use ide_db::base_db::{AnchoredPathBuf, FileId, FileRange};
 use ide_db::{
     label::Label,
-    source_change::{SourceChange, SourceFileEdit},
+    source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
     RootDatabase,
 };
 use syntax::{
@@ -19,7 +19,7 @@ use text_edit::{TextEdit, TextEditBuilder};
 
 use crate::{
     assist_config::{AssistConfig, SnippetCap},
-    Assist, AssistId, AssistKind, GroupLabel, ResolvedAssist,
+    Assist, AssistId, AssistKind, GroupLabel,
 };
 
 /// `AssistContext` allows to apply an assist or check if it could be applied.
@@ -105,46 +105,23 @@ impl<'a> AssistContext<'a> {
 pub(crate) struct Assists {
     resolve: bool,
     file: FileId,
-    buf: Vec<(Assist, Option<SourceChange>)>,
+    buf: Vec<Assist>,
     allowed: Option<Vec<AssistKind>>,
 }
 
 impl Assists {
-    pub(crate) fn new_resolved(ctx: &AssistContext) -> Assists {
+    pub(crate) fn new(ctx: &AssistContext, resolve: bool) -> Assists {
         Assists {
-            resolve: true,
+            resolve,
             file: ctx.frange.file_id,
             buf: Vec::new(),
             allowed: ctx.config.allowed.clone(),
         }
     }
 
-    pub(crate) fn new_unresolved(ctx: &AssistContext) -> Assists {
-        Assists {
-            resolve: false,
-            file: ctx.frange.file_id,
-            buf: Vec::new(),
-            allowed: ctx.config.allowed.clone(),
-        }
-    }
-
-    pub(crate) fn finish_unresolved(self) -> Vec<Assist> {
-        assert!(!self.resolve);
-        self.finish()
-            .into_iter()
-            .map(|(label, edit)| {
-                assert!(edit.is_none());
-                label
-            })
-            .collect()
-    }
-
-    pub(crate) fn finish_resolved(self) -> Vec<ResolvedAssist> {
-        assert!(self.resolve);
-        self.finish()
-            .into_iter()
-            .map(|(label, edit)| ResolvedAssist { assist: label, source_change: edit.unwrap() })
-            .collect()
+    pub(crate) fn finish(mut self) -> Vec<Assist> {
+        self.buf.sort_by_key(|assist| assist.target.len());
+        self.buf
     }
 
     pub(crate) fn add(
@@ -158,7 +135,7 @@ impl Assists {
             return None;
         }
         let label = Label::new(label.into());
-        let assist = Assist { id, label, group: None, target };
+        let assist = Assist { id, label, group: None, target, source_change: None };
         self.add_impl(assist, f)
     }
 
@@ -174,11 +151,11 @@ impl Assists {
             return None;
         }
         let label = Label::new(label.into());
-        let assist = Assist { id, label, group: Some(group.clone()), target };
+        let assist = Assist { id, label, group: Some(group.clone()), target, source_change: None };
         self.add_impl(assist, f)
     }
 
-    fn add_impl(&mut self, assist: Assist, f: impl FnOnce(&mut AssistBuilder)) -> Option<()> {
+    fn add_impl(&mut self, mut assist: Assist, f: impl FnOnce(&mut AssistBuilder)) -> Option<()> {
         let source_change = if self.resolve {
             let mut builder = AssistBuilder::new(self.file);
             f(&mut builder);
@@ -186,16 +163,12 @@ impl Assists {
         } else {
             None
         };
+        assist.source_change = source_change.clone();
 
-        self.buf.push((assist, source_change));
+        self.buf.push(assist);
         Some(())
     }
 
-    fn finish(mut self) -> Vec<(Assist, Option<SourceChange>)> {
-        self.buf.sort_by_key(|(label, _edit)| label.target.len());
-        self.buf
-    }
-
     fn is_allowed(&self, id: &AssistId) -> bool {
         match &self.allowed {
             Some(allowed) => allowed.iter().any(|kind| kind.contains(id.1)),
@@ -209,6 +182,7 @@ pub(crate) struct AssistBuilder {
     file_id: FileId,
     is_snippet: bool,
     source_file_edits: Vec<SourceFileEdit>,
+    file_system_edits: Vec<FileSystemEdit>,
 }
 
 impl AssistBuilder {
@@ -218,6 +192,7 @@ impl AssistBuilder {
             file_id,
             is_snippet: false,
             source_file_edits: Vec::default(),
+            file_system_edits: Vec::default(),
         }
     }
 
@@ -282,12 +257,17 @@ impl AssistBuilder {
             algo::diff(&node, &new).into_text_edit(&mut self.edit);
         }
     }
+    pub(crate) fn create_file(&mut self, dst: AnchoredPathBuf, content: impl Into<String>) {
+        let file_system_edit =
+            FileSystemEdit::CreateFile { dst: dst.clone(), initial_contents: content.into() };
+        self.file_system_edits.push(file_system_edit);
+    }
 
     fn finish(mut self) -> SourceChange {
         self.commit();
         SourceChange {
             source_file_edits: mem::take(&mut self.source_file_edits),
-            file_system_edits: Default::default(),
+            file_system_edits: mem::take(&mut self.file_system_edits),
             is_snippet: self.is_snippet,
         }
     }
diff --git a/crates/assists/src/handlers/add_missing_impl_members.rs b/crates/assists/src/handlers/add_missing_impl_members.rs
index e413505d3..7df05b841 100644
--- a/crates/assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/assists/src/handlers/add_missing_impl_members.rs
@@ -15,7 +15,7 @@ use crate::{
 //
 // ```
 // trait Trait<T> {
-//     Type X;
+//     type X;
 //     fn foo(&self) -> T;
 //     fn bar(&self) {}
 // }
@@ -27,14 +27,16 @@ use crate::{
 // ->
 // ```
 // trait Trait<T> {
-//     Type X;
+//     type X;
 //     fn foo(&self) -> T;
 //     fn bar(&self) {}
 // }
 //
 // impl Trait<u32> for () {
+//     $0type X;
+//
 //     fn foo(&self) -> u32 {
-//         ${0:todo!()}
+//         todo!()
 //     }
 // }
 // ```
@@ -54,13 +56,13 @@ pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -
 //
 // ```
 // trait Trait {
-//     Type X;
+//     type X;
 //     fn foo(&self);
 //     fn bar(&self) {}
 // }
 //
 // impl Trait for () {
-//     Type X = ();
+//     type X = ();
 //     fn foo(&self) {}<|>
 //
 // }
@@ -68,13 +70,13 @@ pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -
 // ->
 // ```
 // trait Trait {
-//     Type X;
+//     type X;
 //     fn foo(&self);
 //     fn bar(&self) {}
 // }
 //
 // impl Trait for () {
-//     Type X = ();
+//     type X = ();
 //     fn foo(&self) {}
 //
 //     $0fn bar(&self) {}
diff --git a/crates/assists/src/handlers/extract_module_to_file.rs b/crates/assists/src/handlers/extract_module_to_file.rs
new file mode 100644
index 000000000..50bf67ef7
--- /dev/null
+++ b/crates/assists/src/handlers/extract_module_to_file.rs
@@ -0,0 +1,133 @@
+use ast::edit::IndentLevel;
+use ide_db::base_db::AnchoredPathBuf;
+use syntax::{
+    ast::{self, edit::AstNodeEdit, NameOwner},
+    AstNode,
+};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: extract_module_to_file
+//
+// This assist extract module to file.
+//
+// ```
+// mod foo {<|>
+//     fn t() {}
+// }
+// ```
+// ->
+// ```
+// mod foo;
+// ```
+pub(crate) fn extract_module_to_file(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let module_ast = ctx.find_node_at_offset::<ast::Module>()?;
+    let module_name = module_ast.name()?;
+
+    let module_def = ctx.sema.to_def(&module_ast)?;
+    let parent_module = module_def.parent(ctx.db())?;
+
+    let module_items = module_ast.item_list()?;
+    let target = module_ast.syntax().text_range();
+    let anchor_file_id = ctx.frange.file_id;
+
+    acc.add(
+        AssistId("extract_module_to_file", AssistKind::RefactorExtract),
+        "Extract module to file",
+        target,
+        |builder| {
+            let path = {
+                let dir = match parent_module.name(ctx.db()) {
+                    Some(name) if !parent_module.is_mod_rs(ctx.db()) => format!("{}/", name),
+                    _ => String::new(),
+                };
+                format!("./{}{}.rs", dir, module_name)
+            };
+            let contents = {
+                let items = module_items.dedent(IndentLevel(1)).to_string();
+                let mut items =
+                    items.trim_start_matches('{').trim_end_matches('}').trim().to_string();
+                if !items.is_empty() {
+                    items.push('\n');
+                }
+                items
+            };
+
+            builder.replace(target, format!("mod {};", module_name));
+
+            let dst = AnchoredPathBuf { anchor: anchor_file_id, path };
+            builder.create_file(dst, contents);
+        },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::check_assist;
+
+    use super::*;
+
+    #[test]
+    fn extract_from_root() {
+        check_assist(
+            extract_module_to_file,
+            r#"
+mod tests {<|>
+    #[test] fn t() {}
+}
+"#,
+            r#"
+//- /main.rs
+mod tests;
+//- /tests.rs
+#[test] fn t() {}
+"#,
+        );
+    }
+
+    #[test]
+    fn extract_from_submodule() {
+        check_assist(
+            extract_module_to_file,
+            r#"
+//- /main.rs
+mod submod;
+//- /submod.rs
+mod inner<|> {
+    fn f() {}
+}
+fn g() {}
+"#,
+            r#"
+//- /submod.rs
+mod inner;
+fn g() {}
+//- /submod/inner.rs
+fn f() {}
+"#,
+        );
+    }
+
+    #[test]
+    fn extract_from_mod_rs() {
+        check_assist(
+            extract_module_to_file,
+            r#"
+//- /main.rs
+mod submodule;
+//- /submodule/mod.rs
+mod inner<|> {
+    fn f() {}
+}
+fn g() {}
+"#,
+            r#"
+//- /submodule/mod.rs
+mod inner;
+fn g() {}
+//- /submodule/inner.rs
+fn f() {}
+"#,
+        );
+    }
+}
diff --git a/crates/assists/src/handlers/invert_if.rs b/crates/assists/src/handlers/invert_if.rs
index 91e2f5c8c..f9c33b3f7 100644
--- a/crates/assists/src/handlers/invert_if.rs
+++ b/crates/assists/src/handlers/invert_if.rs
@@ -78,6 +78,15 @@ mod tests {
     }
 
     #[test]
+    fn invert_if_remove_not_parentheses() {
+        check_assist(
+            invert_if,
+            "fn f() { i<|>f !(x == 3 || x == 4 || x == 5) { 3 * 2 } else { 1 } }",
+            "fn f() { if x == 3 || x == 4 || x == 5 { 1 } else { 3 * 2 } }",
+        )
+    }
+
+    #[test]
     fn invert_if_remove_inequality() {
         check_assist(
             invert_if,
diff --git a/crates/assists/src/handlers/remove_unused_param.rs b/crates/assists/src/handlers/remove_unused_param.rs
index 1ff5e92b0..f72dd49ed 100644
--- a/crates/assists/src/handlers/remove_unused_param.rs
+++ b/crates/assists/src/handlers/remove_unused_param.rs
@@ -2,9 +2,10 @@ use ide_db::{defs::Definition, search::Reference};
 use syntax::{
     algo::find_node_at_range,
     ast::{self, ArgListOwner},
-    AstNode, SyntaxNode, TextRange, T,
+    AstNode, SyntaxKind, SyntaxNode, TextRange, T,
 };
 use test_utils::mark;
+use SyntaxKind::WHITESPACE;
 
 use crate::{
     assist_context::AssistBuilder, utils::next_prev, AssistContext, AssistId, AssistKind, Assists,
@@ -56,7 +57,7 @@ pub(crate) fn remove_unused_param(acc: &mut Assists, ctx: &AssistContext) -> Opt
         "Remove unused parameter",
         param.syntax().text_range(),
         |builder| {
-            builder.delete(range_with_coma(param.syntax()));
+            builder.delete(range_to_remove(param.syntax()));
             for usage in fn_def.usages(&ctx.sema).all() {
                 process_usage(ctx, builder, usage, param_position);
             }
@@ -80,19 +81,34 @@ fn process_usage(
     let arg = call_expr.arg_list()?.args().nth(arg_to_remove)?;
 
     builder.edit_file(usage.file_range.file_id);
-    builder.delete(range_with_coma(arg.syntax()));
+    builder.delete(range_to_remove(arg.syntax()));
 
     Some(())
 }
 
-fn range_with_coma(node: &SyntaxNode) -> TextRange {
-    let up_to = next_prev().find_map(|dir| {
+fn range_to_remove(node: &SyntaxNode) -> TextRange {
+    let up_to_comma = next_prev().find_map(|dir| {
         node.siblings_with_tokens(dir)
             .filter_map(|it| it.into_token())
             .find(|it| it.kind() == T![,])
+            .map(|it| (dir, it))
     });
-    let up_to = up_to.map_or(node.text_range(), |it| it.text_range());
-    node.text_range().cover(up_to)
+    if let Some((dir, token)) = up_to_comma {
+        if node.next_sibling().is_some() {
+            let up_to_space = token
+                .siblings_with_tokens(dir)
+                .skip(1)
+                .take_while(|it| it.kind() == WHITESPACE)
+                .last()
+                .and_then(|it| it.into_token());
+            return node
+                .text_range()
+                .cover(up_to_space.map_or(token.text_range(), |it| it.text_range()));
+        }
+        node.text_range().cover(token.text_range())
+    } else {
+        node.text_range()
+    }
 }
 
 #[cfg(test)]
@@ -119,6 +135,57 @@ fn b() { foo(9, ) }
     }
 
     #[test]
+    fn remove_unused_first_param() {
+        check_assist(
+            remove_unused_param,
+            r#"
+fn foo(<|>x: i32, y: i32) { y; }
+fn a() { foo(1, 2) }
+fn b() { foo(1, 2,) }
+"#,
+            r#"
+fn foo(y: i32) { y; }
+fn a() { foo(2) }
+fn b() { foo(2,) }
+"#,
+        );
+    }
+
+    #[test]
+    fn remove_unused_single_param() {
+        check_assist(
+            remove_unused_param,
+            r#"
+fn foo(<|>x: i32) { 0; }
+fn a() { foo(1) }
+fn b() { foo(1, ) }
+"#,
+            r#"
+fn foo() { 0; }
+fn a() { foo() }
+fn b() { foo( ) }
+"#,
+        );
+    }
+
+    #[test]
+    fn remove_unused_surrounded_by_parms() {
+        check_assist(
+            remove_unused_param,
+            r#"
+fn foo(x: i32, <|>y: i32, z: i32) { x; }
+fn a() { foo(1, 2, 3) }
+fn b() { foo(1, 2, 3,) }
+"#,
+            r#"
+fn foo(x: i32, z: i32) { x; }
+fn a() { foo(1, 3) }
+fn b() { foo(1, 3,) }
+"#,
+        );
+    }
+
+    #[test]
     fn remove_unused_qualified_call() {
         check_assist(
             remove_unused_param,
diff --git a/crates/assists/src/lib.rs b/crates/assists/src/lib.rs
index 6e736ccb3..fdec886e9 100644
--- a/crates/assists/src/lib.rs
+++ b/crates/assists/src/lib.rs
@@ -73,45 +73,32 @@ pub struct Assist {
     /// Target ranges are used to sort assists: the smaller the target range,
     /// the more specific assist is, and so it should be sorted first.
     pub target: TextRange,
-}
-
-#[derive(Debug, Clone)]
-pub struct ResolvedAssist {
-    pub assist: Assist,
-    pub source_change: SourceChange,
+    /// Computing source change sometimes is much more costly then computing the
+    /// other fields. Additionally, the actual change is not required to show
+    /// the lightbulb UI, it only is needed when the user tries to apply an
+    /// assist. So, we compute it lazily: the API allow requesting assists with
+    /// or without source change. We could (and in fact, used to) distinguish
+    /// between resolved and unresolved assists at the type level, but this is
+    /// cumbersome, especially if you want to embed an assist into another data
+    /// structure, such as a diagnostic.
+    pub source_change: Option<SourceChange>,
 }
 
 impl Assist {
     /// Return all the assists applicable at the given position.
-    ///
-    /// Assists are returned in the "unresolved" state, that is only labels are
-    /// returned, without actual edits.
-    pub fn unresolved(db: &RootDatabase, config: &AssistConfig, range: FileRange) -> Vec<Assist> {
-        let sema = Semantics::new(db);
-        let ctx = AssistContext::new(sema, config, range);
-        let mut acc = Assists::new_unresolved(&ctx);
-        handlers::all().iter().for_each(|handler| {
-            handler(&mut acc, &ctx);
-        });
-        acc.finish_unresolved()
-    }
-
-    /// Return all the assists applicable at the given position.
-    ///
-    /// Assists are returned in the "resolved" state, that is with edit fully
-    /// computed.
-    pub fn resolved(
+    pub fn get(
         db: &RootDatabase,
         config: &AssistConfig,
+        resolve: bool,
         range: FileRange,
-    ) -> Vec<ResolvedAssist> {
+    ) -> Vec<Assist> {
         let sema = Semantics::new(db);
         let ctx = AssistContext::new(sema, config, range);
-        let mut acc = Assists::new_resolved(&ctx);
+        let mut acc = Assists::new(&ctx, resolve);
         handlers::all().iter().for_each(|handler| {
             handler(&mut acc, &ctx);
         });
-        acc.finish_resolved()
+        acc.finish()
     }
 }
 
@@ -129,6 +116,7 @@ mod handlers {
     mod convert_integer_literal;
     mod early_return;
     mod expand_glob_import;
+    mod extract_module_to_file;
     mod extract_struct_from_enum_variant;
     mod extract_variable;
     mod fill_match_arms;
@@ -179,6 +167,7 @@ mod handlers {
             convert_integer_literal::convert_integer_literal,
             early_return::convert_to_guarded_return,
             expand_glob_import::expand_glob_import,
+            extract_module_to_file::extract_module_to_file,
             extract_struct_from_enum_variant::extract_struct_from_enum_variant,
             extract_variable::extract_variable,
             fill_match_arms::fill_match_arms,
diff --git a/crates/assists/src/tests.rs b/crates/assists/src/tests.rs
index 709a34d03..21e448fb8 100644
--- a/crates/assists/src/tests.rs
+++ b/crates/assists/src/tests.rs
@@ -2,6 +2,7 @@ mod generated;
 
 use hir::Semantics;
 use ide_db::base_db::{fixture::WithFixture, FileId, FileRange, SourceDatabaseExt};
+use ide_db::source_change::FileSystemEdit;
 use ide_db::RootDatabase;
 use syntax::TextRange;
 use test_utils::{assert_eq_text, extract_offset, extract_range};
@@ -47,25 +48,29 @@ fn check_doc_test(assist_id: &str, before: &str, after: &str) {
     let before = db.file_text(file_id).to_string();
     let frange = FileRange { file_id, range: selection.into() };
 
-    let mut assist = Assist::resolved(&db, &AssistConfig::default(), frange)
+    let assist = Assist::get(&db, &AssistConfig::default(), true, frange)
         .into_iter()
-        .find(|assist| assist.assist.id.0 == assist_id)
+        .find(|assist| assist.id.0 == assist_id)
         .unwrap_or_else(|| {
             panic!(
                 "\n\nAssist is not applicable: {}\nAvailable assists: {}",
                 assist_id,
-                Assist::resolved(&db, &AssistConfig::default(), frange)
+                Assist::get(&db, &AssistConfig::default(), false, frange)
                     .into_iter()
-                    .map(|assist| assist.assist.id.0)
+                    .map(|assist| assist.id.0)
                     .collect::<Vec<_>>()
                     .join(", ")
             )
         });
 
     let actual = {
-        let change = assist.source_change.source_file_edits.pop().unwrap();
+        let source_change = assist.source_change.unwrap();
         let mut actual = before;
-        change.edit.apply(&mut actual);
+        for source_file_edit in source_change.source_file_edits {
+            if source_file_edit.file_id == file_id {
+                source_file_edit.edit.apply(&mut actual)
+            }
+        }
         actual
     };
     assert_eq_text!(&after, &actual);
@@ -86,20 +91,21 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult, assist_label:
     let sema = Semantics::new(&db);
     let config = AssistConfig::default();
     let ctx = AssistContext::new(sema, &config, frange);
-    let mut acc = Assists::new_resolved(&ctx);
+    let mut acc = Assists::new(&ctx, true);
     handler(&mut acc, &ctx);
-    let mut res = acc.finish_resolved();
+    let mut res = acc.finish();
 
     let assist = match assist_label {
-        Some(label) => res.into_iter().find(|resolved| resolved.assist.label == label),
+        Some(label) => res.into_iter().find(|resolved| resolved.label == label),
         None => res.pop(),
     };
 
     match (assist, expected) {
         (Some(assist), ExpectedResult::After(after)) => {
-            let mut source_change = assist.source_change;
+            let mut source_change = assist.source_change.unwrap();
             assert!(!source_change.source_file_edits.is_empty());
-            let skip_header = source_change.source_file_edits.len() == 1;
+            let skip_header = source_change.source_file_edits.len() == 1
+                && source_change.file_system_edits.len() == 0;
             source_change.source_file_edits.sort_by_key(|it| it.file_id);
 
             let mut buf = String::new();
@@ -115,10 +121,25 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult, assist_label:
                 buf.push_str(&text);
             }
 
+            for file_system_edit in source_change.file_system_edits.clone() {
+                match file_system_edit {
+                    FileSystemEdit::CreateFile { dst, initial_contents } => {
+                        let sr = db.file_source_root(dst.anchor);
+                        let sr = db.source_root(sr);
+                        let mut base = sr.path_for_file(&dst.anchor).unwrap().clone();
+                        base.pop();
+                        let created_file_path = format!("{}{}", base.to_string(), &dst.path[1..]);
+                        format_to!(buf, "//- {}\n", created_file_path);
+                        buf.push_str(&initial_contents);
+                    }
+                    _ => (),
+                }
+            }
+
             assert_eq_text!(after, &buf);
         }
         (Some(assist), ExpectedResult::Target(target)) => {
-            let range = assist.assist.target;
+            let range = assist.target;
             assert_eq_text!(&text_without_caret[range], target);
         }
         (Some(_), ExpectedResult::NotApplicable) => panic!("assist should not be applicable!"),
@@ -135,14 +156,11 @@ fn assist_order_field_struct() {
     let (before_cursor_pos, before) = extract_offset(before);
     let (db, file_id) = with_single_file(&before);
     let frange = FileRange { file_id, range: TextRange::empty(before_cursor_pos) };
-    let assists = Assist::resolved(&db, &AssistConfig::default(), frange);
+    let assists = Assist::get(&db, &AssistConfig::default(), false, frange);
     let mut assists = assists.iter();
 
-    assert_eq!(
-        assists.next().expect("expected assist").assist.label,
-        "Change visibility to pub(crate)"
-    );
-    assert_eq!(assists.next().expect("expected assist").assist.label, "Add `#[derive]`");
+    assert_eq!(assists.next().expect("expected assist").label, "Change visibility to pub(crate)");
+    assert_eq!(assists.next().expect("expected assist").label, "Add `#[derive]`");
 }
 
 #[test]
@@ -158,11 +176,11 @@ fn assist_order_if_expr() {
     let (range, before) = extract_range(before);
     let (db, file_id) = with_single_file(&before);
     let frange = FileRange { file_id, range };
-    let assists = Assist::resolved(&db, &AssistConfig::default(), frange);
+    let assists = Assist::get(&db, &AssistConfig::default(), false, frange);
     let mut assists = assists.iter();
 
-    assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
-    assert_eq!(assists.next().expect("expected assist").assist.label, "Replace with match");
+    assert_eq!(assists.next().expect("expected assist").label, "Extract into variable");
+    assert_eq!(assists.next().expect("expected assist").label, "Replace with match");
 }
 
 #[test]
@@ -183,27 +201,27 @@ fn assist_filter_works() {
         let mut cfg = AssistConfig::default();
         cfg.allowed = Some(vec![AssistKind::Refactor]);
 
-        let assists = Assist::resolved(&db, &cfg, frange);
+        let assists = Assist::get(&db, &cfg, false, frange);
         let mut assists = assists.iter();
 
-        assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
-        assert_eq!(assists.next().expect("expected assist").assist.label, "Replace with match");
+        assert_eq!(assists.next().expect("expected assist").label, "Extract into variable");
+        assert_eq!(assists.next().expect("expected assist").label, "Replace with match");
     }
 
     {
         let mut cfg = AssistConfig::default();
         cfg.allowed = Some(vec![AssistKind::RefactorExtract]);
-        let assists = Assist::resolved(&db, &cfg, frange);
+        let assists = Assist::get(&db, &cfg, false, frange);
         assert_eq!(assists.len(), 1);
 
         let mut assists = assists.iter();
-        assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
+        assert_eq!(assists.next().expect("expected assist").label, "Extract into variable");
     }
 
     {
         let mut cfg = AssistConfig::default();
         cfg.allowed = Some(vec![AssistKind::QuickFix]);
-        let assists = Assist::resolved(&db, &cfg, frange);
+        let assists = Assist::get(&db, &cfg, false, frange);
         assert!(assists.is_empty(), "All asserts but quickfixes should be filtered out");
     }
 }
diff --git a/crates/assists/src/tests/generated.rs b/crates/assists/src/tests/generated.rs
index cc7c4a343..d3dfe24e7 100644
--- a/crates/assists/src/tests/generated.rs
+++ b/crates/assists/src/tests/generated.rs
@@ -42,26 +42,26 @@ fn doctest_add_impl_default_members() {
         "add_impl_default_members",
         r#####"
 trait Trait {
-    Type X;
+    type X;
     fn foo(&self);
     fn bar(&self) {}
 }
 
 impl Trait for () {
-    Type X = ();
+    type X = ();
     fn foo(&self) {}<|>
 
 }
 "#####,
         r#####"
 trait Trait {
-    Type X;
+    type X;
     fn foo(&self);
     fn bar(&self) {}
 }
 
 impl Trait for () {
-    Type X = ();
+    type X = ();
     fn foo(&self) {}
 
     $0fn bar(&self) {}
@@ -76,7 +76,7 @@ fn doctest_add_impl_missing_members() {
         "add_impl_missing_members",
         r#####"
 trait Trait<T> {
-    Type X;
+    type X;
     fn foo(&self) -> T;
     fn bar(&self) {}
 }
@@ -87,14 +87,16 @@ impl Trait<u32> for () {<|>
 "#####,
         r#####"
 trait Trait<T> {
-    Type X;
+    type X;
     fn foo(&self) -> T;
     fn bar(&self) {}
 }
 
 impl Trait<u32> for () {
+    $0type X;
+
     fn foo(&self) -> u32 {
-        ${0:todo!()}
+        todo!()
     }
 }
 "#####,
@@ -236,6 +238,21 @@ fn qux(bar: Bar, baz: Baz) {}
 }
 
 #[test]
+fn doctest_extract_module_to_file() {
+    check_doc_test(
+        "extract_module_to_file",
+        r#####"
+mod foo {<|>
+    fn t() {}
+}
+"#####,
+        r#####"
+mod foo;
+"#####,
+    )
+}
+
+#[test]
 fn doctest_extract_struct_from_enum_variant() {
     check_doc_test(
         "extract_struct_from_enum_variant",
diff --git a/crates/assists/src/utils.rs b/crates/assists/src/utils.rs
index f2cacf7c8..d41084b59 100644
--- a/crates/assists/src/utils.rs
+++ b/crates/assists/src/utils.rs
@@ -232,7 +232,13 @@ fn invert_special_case(expr: &ast::Expr) -> Option<ast::Expr> {
             };
             Some(make::expr_method_call(receiver, method, arg_list))
         }
-        ast::Expr::PrefixExpr(pe) if pe.op_kind()? == ast::PrefixOp::Not => pe.expr(),
+        ast::Expr::PrefixExpr(pe) if pe.op_kind()? == ast::PrefixOp::Not => {
+            if let ast::Expr::ParenExpr(parexpr) = pe.expr()? {
+                parexpr.expr()
+            } else {
+                pe.expr()
+            }
+        }
         // FIXME:
         // ast::Expr::Literal(true | false )
         _ => None,
diff --git a/crates/completion/src/completions.rs b/crates/completion/src/completions.rs
index 1ef6b5f48..d9fe13485 100644
--- a/crates/completion/src/completions.rs
+++ b/crates/completion/src/completions.rs
@@ -19,9 +19,14 @@ use hir::{ModPath, ScopeDef, Type};
 use crate::{
     item::Builder,
     render::{
-        const_::render_const, enum_variant::render_variant, function::render_fn,
-        macro_::render_macro, render_field, render_resolution, render_tuple_field,
-        type_alias::render_type_alias, RenderContext,
+        const_::render_const,
+        enum_variant::render_variant,
+        function::render_fn,
+        macro_::render_macro,
+        pattern::{render_struct_pat, render_variant_pat},
+        render_field, render_resolution, render_tuple_field,
+        type_alias::render_type_alias,
+        RenderContext,
     },
     CompletionContext, CompletionItem,
 };
@@ -105,6 +110,28 @@ impl Completions {
         self.add(item)
     }
 
+    pub(crate) fn add_variant_pat(
+        &mut self,
+        ctx: &CompletionContext,
+        variant: hir::Variant,
+        local_name: Option<hir::Name>,
+    ) {
+        if let Some(item) = render_variant_pat(RenderContext::new(ctx), variant, local_name) {
+            self.add(item);
+        }
+    }
+
+    pub(crate) fn add_struct_pat(
+        &mut self,
+        ctx: &CompletionContext,
+        strukt: hir::Struct,
+        local_name: Option<hir::Name>,
+    ) {
+        if let Some(item) = render_struct_pat(RenderContext::new(ctx), strukt, local_name) {
+            self.add(item);
+        }
+    }
+
     pub(crate) fn add_const(&mut self, ctx: &CompletionContext, constant: hir::Const) {
         if let Some(item) = render_const(RenderContext::new(ctx), constant) {
             self.add(item);
diff --git a/crates/completion/src/completions/pattern.rs b/crates/completion/src/completions/pattern.rs
index 4d56731ec..eee31098d 100644
--- a/crates/completion/src/completions/pattern.rs
+++ b/crates/completion/src/completions/pattern.rs
@@ -2,9 +2,9 @@
 
 use crate::{CompletionContext, Completions};
 
-/// Completes constats and paths in patterns.
+/// Completes constants and paths in patterns.
 pub(crate) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
-    if !(ctx.is_pat_binding_or_const || ctx.is_irrefutable_let_pat_binding) {
+    if !(ctx.is_pat_binding_or_const || ctx.is_irrefutable_pat_binding) {
         return;
     }
     if ctx.record_pat_syntax.is_some() {
@@ -15,20 +15,21 @@ pub(crate) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
     // suggest variants + auto-imports
     ctx.scope.process_all_names(&mut |name, res| {
         let add_resolution = match &res {
-            hir::ScopeDef::ModuleDef(def) => {
-                if ctx.is_irrefutable_let_pat_binding {
-                    matches!(def, hir::ModuleDef::Adt(hir::Adt::Struct(_)))
-                } else {
-                    matches!(
-                        def,
-                        hir::ModuleDef::Adt(hir::Adt::Enum(..))
-                            | hir::ModuleDef::Adt(hir::Adt::Struct(..))
-                            | hir::ModuleDef::Variant(..)
-                            | hir::ModuleDef::Const(..)
-                            | hir::ModuleDef::Module(..)
-                    )
+            hir::ScopeDef::ModuleDef(def) => match def {
+                hir::ModuleDef::Adt(hir::Adt::Struct(strukt)) => {
+                    acc.add_struct_pat(ctx, strukt.clone(), Some(name.clone()));
+                    true
                 }
-            }
+                hir::ModuleDef::Variant(variant) if !ctx.is_irrefutable_pat_binding => {
+                    acc.add_variant_pat(ctx, variant.clone(), Some(name.clone()));
+                    true
+                }
+                hir::ModuleDef::Adt(hir::Adt::Enum(..))
+                | hir::ModuleDef::Variant(..)
+                | hir::ModuleDef::Const(..)
+                | hir::ModuleDef::Module(..) => !ctx.is_irrefutable_pat_binding,
+                _ => false,
+            },
             hir::ScopeDef::MacroDef(_) => true,
             _ => false,
         };
@@ -42,13 +43,21 @@ pub(crate) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
 mod tests {
     use expect_test::{expect, Expect};
 
-    use crate::{test_utils::completion_list, CompletionKind};
+    use crate::{
+        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_snippet(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Snippet);
+        expect.assert_eq(&actual)
+    }
+
     #[test]
     fn completes_enum_variants_and_modules() {
         check(
@@ -69,7 +78,7 @@ fn foo() {
                 en E
                 ct Z
                 st Bar
-                ev X   ()
+                ev X
                 md m
             "#]],
         );
@@ -114,4 +123,139 @@ fn foo() {
             "#]],
         );
     }
+
+    #[test]
+    fn completes_in_param() {
+        check(
+            r#"
+enum E { X }
+
+static FOO: E = E::X;
+struct Bar { f: u32 }
+
+fn foo(<|>) {
+}
+"#,
+            expect![[r#"
+                st Bar
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_pat_in_let() {
+        check_snippet(
+            r#"
+struct Bar { f: u32 }
+
+fn foo() {
+   let <|>
+}
+"#,
+            expect![[r#"
+                bn Bar Bar { f$1 }$0
+            "#]],
+        );
+    }
+
+    #[test]
+    fn completes_param_pattern() {
+        check_snippet(
+            r#"
+struct Foo { bar: String, baz: String }
+struct Bar(String, String);
+struct Baz;
+fn outer(<|>) {}
+"#,
+            expect![[r#"
+                bn Foo Foo { bar$1, baz$2 }: Foo$0
+                bn Bar Bar($1, $2): Bar$0
+            "#]],
+        )
+    }
+
+    #[test]
+    fn completes_let_pattern() {
+        check_snippet(
+            r#"
+struct Foo { bar: String, baz: String }
+struct Bar(String, String);
+struct Baz;
+fn outer() {
+    let <|>
+}
+"#,
+            expect![[r#"
+                bn Foo Foo { bar$1, baz$2 }$0
+                bn Bar Bar($1, $2)$0
+            "#]],
+        )
+    }
+
+    #[test]
+    fn completes_refutable_pattern() {
+        check_snippet(
+            r#"
+struct Foo { bar: i32, baz: i32 }
+struct Bar(String, String);
+struct Baz;
+fn outer() {
+    match () {
+        <|>
+    }
+}
+"#,
+            expect![[r#"
+                bn Foo Foo { bar$1, baz$2 }$0
+                bn Bar Bar($1, $2)$0
+            "#]],
+        )
+    }
+
+    #[test]
+    fn omits_private_fields_pat() {
+        check_snippet(
+            r#"
+mod foo {
+    pub struct Foo { pub bar: i32, baz: i32 }
+    pub struct Bar(pub String, String);
+    pub struct Invisible(String, String);
+}
+use foo::*;
+
+fn outer() {
+    match () {
+        <|>
+    }
+}
+"#,
+            expect![[r#"
+                bn Foo Foo { bar$1, .. }$0
+                bn Bar Bar($1, ..)$0
+            "#]],
+        )
+    }
+
+    #[test]
+    fn only_shows_ident_completion() {
+        check_edit(
+            "Foo",
+            r#"
+struct Foo(i32);
+fn main() {
+    match Foo(92) {
+        <|>(92) => (),
+    }
+}
+"#,
+            r#"
+struct Foo(i32);
+fn main() {
+    match Foo(92) {
+        Foo(92) => (),
+    }
+}
+"#,
+        );
+    }
 }
diff --git a/crates/completion/src/completions/qualified_path.rs b/crates/completion/src/completions/qualified_path.rs
index 1300f00b2..882c4dcbc 100644
--- a/crates/completion/src/completions/qualified_path.rs
+++ b/crates/completion/src/completions/qualified_path.rs
@@ -118,6 +118,12 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     _ => return,
                 };
 
+                if let Some(Adt::Enum(e)) = ty.as_adt() {
+                    for variant in e.variants(ctx.db) {
+                        acc.add_enum_variant(ctx, variant, None);
+                    }
+                }
+
                 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| {
@@ -752,4 +758,27 @@ fn main() {
             "#]],
         );
     }
+
+    #[test]
+    fn completes_self_enum() {
+        check(
+            r#"
+enum Foo {
+    Bar,
+    Baz,
+}
+
+impl Foo {
+    fn foo(self) {
+        Self::<|>
+    }
+}
+"#,
+            expect![[r#"
+                ev Bar    ()
+                ev Baz    ()
+                me foo(…) fn foo(self)
+            "#]],
+        );
+    }
 }
diff --git a/crates/completion/src/completions/unqualified_path.rs b/crates/completion/src/completions/unqualified_path.rs
index 099ffb4d4..d09849752 100644
--- a/crates/completion/src/completions/unqualified_path.rs
+++ b/crates/completion/src/completions/unqualified_path.rs
@@ -1,5 +1,7 @@
 //! Completion of names from the current scope, e.g. locals and imported items.
 
+use std::iter;
+
 use either::Either;
 use hir::{Adt, ModPath, ModuleDef, ScopeDef, Type};
 use ide_db::helpers::insert_use::ImportScope;
@@ -50,7 +52,9 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
 }
 
 fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &Type) {
-    if let Some(Adt::Enum(enum_data)) = ty.as_adt() {
+    if let Some(Adt::Enum(enum_data)) =
+        iter::successors(Some(ty.clone()), |ty| ty.remove_ref()).last().and_then(|ty| ty.as_adt())
+    {
         let variants = enum_data.variants(ctx.db);
 
         let module = if let Some(module) = ctx.scope.module() {
@@ -701,6 +705,7 @@ fn main() { <|> }
             "#]],
         );
     }
+
     #[test]
     fn completes_enum_variant_matcharm() {
         check(
@@ -722,6 +727,26 @@ fn main() {
     }
 
     #[test]
+    fn completes_enum_variant_matcharm_ref() {
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
+
+fn main() {
+    let foo = Foo::Quux;
+    match &foo { Qu<|> }
+}
+"#,
+            expect![[r#"
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+                en Foo
+            "#]],
+        )
+    }
+
+    #[test]
     fn completes_enum_variant_iflet() {
         check(
             r#"
diff --git a/crates/completion/src/context.rs b/crates/completion/src/context.rs
index 5cd11cf77..41de324d8 100644
--- a/crates/completion/src/context.rs
+++ b/crates/completion/src/context.rs
@@ -51,7 +51,7 @@ pub(crate) struct CompletionContext<'a> {
     /// 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,
-    pub(super) is_irrefutable_let_pat_binding: bool,
+    pub(super) is_irrefutable_pat_binding: 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).
@@ -147,7 +147,7 @@ impl<'a> CompletionContext<'a> {
             active_parameter: ActiveParameter::at(db, position),
             is_param: false,
             is_pat_binding_or_const: false,
-            is_irrefutable_let_pat_binding: false,
+            is_irrefutable_pat_binding: false,
             is_trivial_path: false,
             path_qual: None,
             after_if: false,
@@ -327,14 +327,19 @@ impl<'a> CompletionContext<'a> {
                 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;
-                            self.is_irrefutable_let_pat_binding = true;
+                if let Some(Some(pat)) = bind_pat.syntax().ancestors().find_map(|node| {
+                    match_ast! {
+                        match node {
+                            ast::LetStmt(it) => Some(it.pat()),
+                            ast::Param(it) => Some(it.pat()),
+                            _ => None,
                         }
                     }
+                }) {
+                    if pat.syntax().text_range().contains_range(bind_pat.syntax().text_range()) {
+                        self.is_pat_binding_or_const = false;
+                        self.is_irrefutable_pat_binding = true;
+                    }
                 }
             }
             if is_node::<ast::Param>(name.syntax()) {
diff --git a/crates/completion/src/render.rs b/crates/completion/src/render.rs
index 1092a4825..1ba7201a1 100644
--- a/crates/completion/src/render.rs
+++ b/crates/completion/src/render.rs
@@ -5,6 +5,7 @@ pub(crate) mod macro_;
 pub(crate) mod function;
 pub(crate) mod enum_variant;
 pub(crate) mod const_;
+pub(crate) mod pattern;
 pub(crate) mod type_alias;
 
 mod builder_ext;
@@ -159,6 +160,12 @@ impl<'a> Render<'a> {
                 let item = render_fn(self.ctx, import_to_add, Some(local_name), *func);
                 return Some(item);
             }
+            ScopeDef::ModuleDef(Variant(_))
+                if self.ctx.completion.is_pat_binding_or_const
+                    | self.ctx.completion.is_irrefutable_pat_binding =>
+            {
+                CompletionItemKind::EnumVariant
+            }
             ScopeDef::ModuleDef(Variant(var)) => {
                 let item = render_variant(self.ctx, import_to_add, Some(local_name), *var, None);
                 return Some(item);
diff --git a/crates/completion/src/render/builder_ext.rs b/crates/completion/src/render/builder_ext.rs
index ce8718bd5..d053a988b 100644
--- a/crates/completion/src/render/builder_ext.rs
+++ b/crates/completion/src/render/builder_ext.rs
@@ -34,7 +34,6 @@ impl Builder {
             return false;
         }
         if ctx.is_pattern_call {
-            mark::hit!(dont_duplicate_pattern_parens);
             return false;
         }
         if ctx.is_call {
diff --git a/crates/completion/src/render/enum_variant.rs b/crates/completion/src/render/enum_variant.rs
index 7176fd9b3..732e139ec 100644
--- a/crates/completion/src/render/enum_variant.rs
+++ b/crates/completion/src/render/enum_variant.rs
@@ -126,50 +126,5 @@ fn main() -> Option<i32> {
 }
 "#,
         );
-        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) => (),
-    }
-}
-"#,
-        );
     }
 }
diff --git a/crates/completion/src/render/pattern.rs b/crates/completion/src/render/pattern.rs
new file mode 100644
index 000000000..a3b6a3cac
--- /dev/null
+++ b/crates/completion/src/render/pattern.rs
@@ -0,0 +1,148 @@
+//! Renderer for patterns.
+
+use hir::{db::HirDatabase, HasAttrs, HasVisibility, Name, StructKind};
+use itertools::Itertools;
+
+use crate::{
+    config::SnippetCap, item::CompletionKind, render::RenderContext, CompletionItem,
+    CompletionItemKind,
+};
+
+fn visible_fields(
+    ctx: &RenderContext<'_>,
+    fields: &[hir::Field],
+    item: impl HasAttrs,
+) -> Option<(Vec<hir::Field>, bool)> {
+    let module = ctx.completion.scope.module()?;
+    let n_fields = fields.len();
+    let fields = fields
+        .into_iter()
+        .filter(|field| field.is_visible_from(ctx.db(), module))
+        .copied()
+        .collect::<Vec<_>>();
+
+    let fields_omitted =
+        n_fields - fields.len() > 0 || item.attrs(ctx.db()).by_key("non_exhaustive").exists();
+    Some((fields, fields_omitted))
+}
+
+pub(crate) fn render_struct_pat(
+    ctx: RenderContext<'_>,
+    strukt: hir::Struct,
+    local_name: Option<Name>,
+) -> Option<CompletionItem> {
+    let _p = profile::span("render_struct_pat");
+
+    let fields = strukt.fields(ctx.db());
+    let (visible_fields, fields_omitted) = visible_fields(&ctx, &fields, strukt)?;
+
+    if visible_fields.is_empty() {
+        // Matching a struct without matching its fields is pointless, unlike matching a Variant without its fields
+        return None;
+    }
+
+    let name = local_name.unwrap_or_else(|| strukt.name(ctx.db())).to_string();
+    let pat = render_pat(&ctx, &name, strukt.kind(ctx.db()), &visible_fields, fields_omitted)?;
+
+    Some(build_completion(ctx, name, pat, strukt))
+}
+
+pub(crate) fn render_variant_pat(
+    ctx: RenderContext<'_>,
+    variant: hir::Variant,
+    local_name: Option<Name>,
+) -> Option<CompletionItem> {
+    let _p = profile::span("render_variant_pat");
+
+    let fields = variant.fields(ctx.db());
+    let (visible_fields, fields_omitted) = visible_fields(&ctx, &fields, variant)?;
+
+    let name = local_name.unwrap_or_else(|| variant.name(ctx.db())).to_string();
+    let pat = render_pat(&ctx, &name, variant.kind(ctx.db()), &visible_fields, fields_omitted)?;
+
+    Some(build_completion(ctx, name, pat, variant))
+}
+
+fn build_completion(
+    ctx: RenderContext<'_>,
+    name: String,
+    pat: String,
+    item: impl HasAttrs + Copy,
+) -> CompletionItem {
+    let completion = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), name)
+        .kind(CompletionItemKind::Binding)
+        .set_documentation(ctx.docs(item))
+        .set_deprecated(ctx.is_deprecated(item))
+        .detail(&pat);
+    let completion = if let Some(snippet_cap) = ctx.snippet_cap() {
+        completion.insert_snippet(snippet_cap, pat)
+    } else {
+        completion.insert_text(pat)
+    };
+    completion.build()
+}
+
+fn render_pat(
+    ctx: &RenderContext<'_>,
+    name: &str,
+    kind: StructKind,
+    fields: &[hir::Field],
+    fields_omitted: bool,
+) -> Option<String> {
+    let mut pat = match kind {
+        StructKind::Tuple if ctx.snippet_cap().is_some() => {
+            render_tuple_as_pat(&fields, &name, fields_omitted)
+        }
+        StructKind::Record => {
+            render_record_as_pat(ctx.db(), ctx.snippet_cap(), &fields, &name, fields_omitted)
+        }
+        _ => return None,
+    };
+
+    if ctx.completion.is_param {
+        pat.push(':');
+        pat.push(' ');
+        pat.push_str(&name);
+    }
+    if ctx.snippet_cap().is_some() {
+        pat.push_str("$0");
+    }
+    Some(pat)
+}
+
+fn render_record_as_pat(
+    db: &dyn HirDatabase,
+    snippet_cap: Option<SnippetCap>,
+    fields: &[hir::Field],
+    name: &str,
+    fields_omitted: bool,
+) -> String {
+    let fields = fields.iter();
+    if snippet_cap.is_some() {
+        format!(
+            "{name} {{ {}{} }}",
+            fields
+                .enumerate()
+                .map(|(idx, field)| format!("{}${}", field.name(db), idx + 1))
+                .format(", "),
+            if fields_omitted { ", .." } else { "" },
+            name = name
+        )
+    } else {
+        format!(
+            "{name} {{ {}{} }}",
+            fields.map(|field| field.name(db)).format(", "),
+            if fields_omitted { ", .." } else { "" },
+            name = name
+        )
+    }
+}
+
+fn render_tuple_as_pat(fields: &[hir::Field], name: &str, fields_omitted: bool) -> String {
+    format!(
+        "{name}({}{})",
+        fields.iter().enumerate().map(|(idx, _)| format!("${}", idx + 1)).format(", "),
+        if fields_omitted { ", .." } else { "" },
+        name = name
+    )
+}
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index d6c7e71ea..b7ded3478 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -9,7 +9,7 @@ use hir_def::{
     adt::StructKind,
     adt::VariantData,
     builtin_type::BuiltinType,
-    expr::{BindingAnnotation, Pat, PatId},
+    expr::{BindingAnnotation, LabelId, Pat, PatId},
     import_map,
     item_tree::ItemTreeNode,
     lang_item::LangItemTarget,
@@ -374,8 +374,6 @@ impl Module {
         let crate_def_map = db.crate_def_map(self.id.krate);
         crate_def_map.add_diagnostics(db.upcast(), self.id.local_id, sink);
         for decl in self.declarations(db) {
-            decl.diagnostics(db, sink);
-
             match decl {
                 crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
                 crate::ModuleDef::Module(m) => {
@@ -384,7 +382,9 @@ impl Module {
                         m.diagnostics(db, sink)
                     }
                 }
-                _ => (),
+                _ => {
+                    decl.diagnostics(db, sink);
+                }
             }
         }
 
@@ -511,6 +511,10 @@ impl Struct {
         db.struct_data(self.id).repr.clone()
     }
 
+    pub fn kind(self, db: &dyn HirDatabase) -> StructKind {
+        self.variant_data(db).kind()
+    }
+
     fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
         db.struct_data(self.id).variant_data.clone()
     }
@@ -1202,6 +1206,34 @@ impl Local {
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct Label {
+    pub(crate) parent: DefWithBodyId,
+    pub(crate) label_id: LabelId,
+}
+
+impl Label {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.parent(db).module(db)
+    }
+
+    pub fn parent(self, _db: &dyn HirDatabase) -> DefWithBody {
+        self.parent.into()
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        let body = db.body(self.parent.into());
+        body[self.label_id].name.clone()
+    }
+
+    pub fn source(self, db: &dyn HirDatabase) -> InFile<ast::Label> {
+        let (_body, source_map) = db.body_with_source_map(self.parent.into());
+        let src = source_map.label_syntax(self.label_id);
+        let root = src.file_syntax(db.upcast());
+        src.map(|ast| ast.to_node(&root))
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum GenericParam {
     TypeParam(TypeParam),
     LifetimeParam(LifetimeParam),
@@ -1268,7 +1300,6 @@ impl LifetimeParam {
     }
 }
 
-// FIXME: rename from `ImplDef` to `Impl`
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Impl {
     pub(crate) id: ImplId,
diff --git a/crates/hir/src/from_id.rs b/crates/hir/src/from_id.rs
index 8e0c571b8..a0792b9a6 100644
--- a/crates/hir/src/from_id.rs
+++ b/crates/hir/src/from_id.rs
@@ -4,12 +4,15 @@
 //! are splitting the hir.
 
 use hir_def::{
-    expr::PatId, item_scope::ItemInNs, AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId,
-    GenericDefId, ModuleDefId, VariantId,
+    expr::{LabelId, PatId},
+    item_scope::ItemInNs,
+    AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, GenericDefId, ModuleDefId,
+    VariantId,
 };
 
 use crate::{
-    Adt, AssocItem, DefWithBody, Field, GenericDef, Local, MacroDef, ModuleDef, Variant, VariantDef,
+    Adt, AssocItem, DefWithBody, Field, GenericDef, Label, Local, MacroDef, ModuleDef, Variant,
+    VariantDef,
 };
 
 macro_rules! from_id {
@@ -228,6 +231,12 @@ impl From<(DefWithBodyId, PatId)> for Local {
     }
 }
 
+impl From<(DefWithBodyId, LabelId)> for Label {
+    fn from((parent, label_id): (DefWithBodyId, LabelId)) -> Self {
+        Label { parent, label_id }
+    }
+}
+
 impl From<MacroDef> for ItemInNs {
     fn from(macro_def: MacroDef) -> Self {
         ItemInNs::Macros(macro_def.into())
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index bdd270c58..7ac9fd507 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -35,8 +35,8 @@ pub use crate::{
     code_model::{
         Access, Adt, AsAssocItem, AssocItem, AssocItemContainer, Callable, CallableKind, Const,
         Crate, CrateDependency, DefWithBody, Enum, Field, FieldSource, Function, GenericDef,
-        HasVisibility, Impl, LifetimeParam, Local, MacroDef, Module, ModuleDef, ScopeDef, Static,
-        Struct, Trait, Type, TypeAlias, TypeParam, Union, Variant, VariantDef,
+        HasVisibility, Impl, Label, LifetimeParam, Local, MacroDef, Module, ModuleDef, ScopeDef,
+        Static, Struct, Trait, Type, TypeAlias, TypeParam, Union, Variant, VariantDef,
     },
     has_source::HasSource,
     semantics::{PathResolution, Semantics, SemanticsScope},
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 25ebf73d8..67cd16e31 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -15,7 +15,7 @@ use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet};
 use syntax::{
     algo::find_node_at_offset,
-    ast::{self, GenericParamsOwner},
+    ast::{self, GenericParamsOwner, LoopBodyOwner},
     match_ast, AstNode, SyntaxNode, SyntaxToken, TextSize,
 };
 
@@ -25,8 +25,8 @@ use crate::{
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, SourceAnalyzer},
-    AssocItem, Callable, Crate, Field, Function, HirFileId, Impl, InFile, LifetimeParam, Local,
-    MacroDef, Module, ModuleDef, Name, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam,
+    AssocItem, Callable, Crate, Field, Function, HirFileId, Impl, InFile, Label, LifetimeParam,
+    Local, MacroDef, Module, ModuleDef, Name, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam,
     VariantDef,
 };
 
@@ -182,6 +182,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_lifetime_param(lifetime)
     }
 
+    pub fn resolve_label(&self, lifetime: &ast::Lifetime) -> Option<Label> {
+        self.imp.resolve_label(lifetime)
+    }
+
     pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
         self.imp.type_of_expr(expr)
     }
@@ -425,6 +429,28 @@ impl<'db> SemanticsImpl<'db> {
         ToDef::to_def(self, src)
     }
 
+    fn resolve_label(&self, lifetime: &ast::Lifetime) -> Option<Label> {
+        let text = lifetime.text();
+        let label = lifetime.syntax().ancestors().find_map(|syn| {
+            let label = match_ast! {
+                match syn {
+                    ast::ForExpr(it) => it.label(),
+                    ast::WhileExpr(it) => it.label(),
+                    ast::LoopExpr(it) => it.label(),
+                    ast::EffectExpr(it) => it.label(),
+                    _ => None,
+                }
+            };
+            label.filter(|l| {
+                l.lifetime()
+                    .and_then(|lt| lt.lifetime_ident_token())
+                    .map_or(false, |lt| lt.text() == text)
+            })
+        })?;
+        let src = self.find_file(label.syntax().clone()).with_value(label);
+        ToDef::to_def(self, src)
+    }
+
     fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
         self.analyze(expr.syntax()).type_of_expr(self.db, expr)
     }
@@ -720,6 +746,7 @@ to_def_impls![
     (crate::LifetimeParam, ast::LifetimeParam, lifetime_param_to_def),
     (crate::MacroDef, ast::MacroRules, macro_rules_to_def),
     (crate::Local, ast::IdentPat, bind_pat_to_def),
+    (crate::Label, ast::Label, label_to_def),
 ];
 
 fn find_root(node: &SyntaxNode) -> SyntaxNode {
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 3efca5baa..424e6e8a9 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -4,7 +4,7 @@ use base_db::FileId;
 use hir_def::{
     child_by_source::ChildBySource,
     dyn_map::DynMap,
-    expr::PatId,
+    expr::{LabelId, PatId},
     keys::{self, Key},
     ConstId, DefWithBodyId, EnumId, EnumVariantId, FieldId, FunctionId, GenericDefId, ImplId,
     LifetimeParamId, ModuleId, StaticId, StructId, TraitId, TypeAliasId, TypeParamId, UnionId,
@@ -108,12 +108,21 @@ impl SourceToDefCtx<'_, '_> {
         &mut self,
         src: InFile<ast::IdentPat>,
     ) -> Option<(DefWithBodyId, PatId)> {
-        let container = self.find_pat_container(src.as_ref().map(|it| it.syntax()))?;
+        let container = self.find_pat_or_label_container(src.as_ref().map(|it| it.syntax()))?;
         let (_body, source_map) = self.db.body_with_source_map(container);
         let src = src.map(ast::Pat::from);
         let pat_id = source_map.node_pat(src.as_ref())?;
         Some((container, pat_id))
     }
+    pub(super) fn label_to_def(
+        &mut self,
+        src: InFile<ast::Label>,
+    ) -> Option<(DefWithBodyId, LabelId)> {
+        let container = self.find_pat_or_label_container(src.as_ref().map(|it| it.syntax()))?;
+        let (_body, source_map) = self.db.body_with_source_map(container);
+        let label_id = source_map.node_label(src.as_ref())?;
+        Some((container, label_id))
+    }
 
     fn to_def<Ast: AstNode + 'static, ID: Copy + 'static>(
         &mut self,
@@ -237,7 +246,7 @@ impl SourceToDefCtx<'_, '_> {
         None
     }
 
-    fn find_pat_container(&mut self, src: InFile<&SyntaxNode>) -> Option<DefWithBodyId> {
+    fn find_pat_or_label_container(&mut self, src: InFile<&SyntaxNode>) -> Option<DefWithBodyId> {
         for container in src.cloned().ancestors_with_macros(self.db.upcast()).skip(1) {
             let res: DefWithBodyId = match_ast! {
                 match (container.value) {
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 998b82601..d07004b9d 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -26,7 +26,7 @@ pub(crate) use lower::LowerCtx;
 use crate::{
     attr::{Attrs, RawAttrs},
     db::DefDatabase,
-    expr::{Expr, ExprId, Pat, PatId},
+    expr::{Expr, ExprId, Label, LabelId, Pat, PatId},
     item_scope::BuiltinShadowMode,
     item_scope::ItemScope,
     nameres::CrateDefMap,
@@ -226,6 +226,7 @@ pub(crate) struct Mark {
 pub struct Body {
     pub exprs: Arena<Expr>,
     pub pats: Arena<Pat>,
+    pub labels: Arena<Label>,
     /// The patterns for the function's parameters. While the parameter types are
     /// part of the function signature, the patterns are not (they don't change
     /// the external type of the function).
@@ -244,6 +245,8 @@ pub type ExprSource = InFile<ExprPtr>;
 pub type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>;
 pub type PatSource = InFile<PatPtr>;
 
+pub type LabelPtr = AstPtr<ast::Label>;
+pub type LabelSource = InFile<LabelPtr>;
 /// An item body together with the mapping from syntax nodes to HIR expression
 /// IDs. This is needed to go from e.g. a position in a file to the HIR
 /// expression containing it; but for type inference etc., we want to operate on
@@ -261,6 +264,8 @@ pub struct BodySourceMap {
     expr_map_back: ArenaMap<ExprId, Result<ExprSource, SyntheticSyntax>>,
     pat_map: FxHashMap<PatSource, PatId>,
     pat_map_back: ArenaMap<PatId, Result<PatSource, SyntheticSyntax>>,
+    label_map: FxHashMap<LabelSource, LabelId>,
+    label_map_back: ArenaMap<LabelId, LabelSource>,
     field_map: FxHashMap<(ExprId, usize), InFile<AstPtr<ast::RecordExprField>>>,
     expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>,
 
@@ -334,6 +339,14 @@ impl Index<PatId> for Body {
     }
 }
 
+impl Index<LabelId> for Body {
+    type Output = Label;
+
+    fn index(&self, label: LabelId) -> &Label {
+        &self.labels[label]
+    }
+}
+
 impl BodySourceMap {
     pub fn expr_syntax(&self, expr: ExprId) -> Result<ExprSource, SyntheticSyntax> {
         self.expr_map_back[expr].clone()
@@ -363,6 +376,15 @@ impl BodySourceMap {
         self.pat_map.get(&src).cloned()
     }
 
+    pub fn label_syntax(&self, label: LabelId) -> LabelSource {
+        self.label_map_back[label].clone()
+    }
+
+    pub fn node_label(&self, node: InFile<&ast::Label>) -> Option<LabelId> {
+        let src = node.map(|it| AstPtr::new(it));
+        self.label_map.get(&src).cloned()
+    }
+
     pub fn field_syntax(&self, expr: ExprId, field: usize) -> InFile<AstPtr<ast::RecordExprField>> {
         self.field_map[&(expr, field)].clone()
     }
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index 0f404be1b..17c72779b 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -22,13 +22,14 @@ use test_utils::mark;
 
 use crate::{
     adt::StructKind,
-    body::{Body, BodySourceMap, Expander, PatPtr, SyntheticSyntax},
+    body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
     builtin_type::{BuiltinFloat, BuiltinInt},
     db::DefDatabase,
     diagnostics::{InactiveCode, MacroError, UnresolvedProcMacro},
     expr::{
-        dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal,
-        LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
+        dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Label,
+        LabelId, Literal, LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField,
+        Statement,
     },
     item_scope::BuiltinShadowMode,
     item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
@@ -72,6 +73,7 @@ pub(super) fn lower(
         body: Body {
             exprs: Arena::default(),
             pats: Arena::default(),
+            labels: Arena::default(),
             params: Vec::new(),
             body_expr: dummy_expr_id(),
             item_scope: Default::default(),
@@ -175,6 +177,18 @@ impl ExprCollector<'_> {
         id
     }
 
+    fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
+        let src = self.expander.to_source(ptr);
+        let id = self.make_label(label, src.clone());
+        self.source_map.label_map.insert(src, id);
+        id
+    }
+    fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
+        let id = self.body.labels.alloc(label);
+        self.source_map.label_map_back.insert(id, src);
+        id
+    }
+
     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
         let syntax_ptr = AstPtr::new(&expr);
         if self.check_cfg(&expr).is_none() {
@@ -228,37 +242,40 @@ impl ExprCollector<'_> {
                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
                 }
                 // FIXME: we need to record these effects somewhere...
-                ast::Effect::Label(label) => match e.block_expr() {
-                    Some(block) => {
-                        let res = self.collect_block(block);
-                        match &mut self.body.exprs[res] {
-                            Expr::Block { label: block_label, .. } => {
-                                *block_label = label.lifetime().map(|t| Name::new_lifetime(&t))
+                ast::Effect::Label(label) => {
+                    let label = self.collect_label(label);
+                    match e.block_expr() {
+                        Some(block) => {
+                            let res = self.collect_block(block);
+                            match &mut self.body.exprs[res] {
+                                Expr::Block { label: block_label, .. } => {
+                                    *block_label = Some(label);
+                                }
+                                _ => unreachable!(),
                             }
-                            _ => unreachable!(),
+                            res
                         }
-                        res
+                        None => self.missing_expr(),
                     }
-                    None => self.missing_expr(),
-                },
+                }
                 // FIXME: we need to record these effects somewhere...
                 ast::Effect::Async(_) => {
                     let body = self.collect_block_opt(e.block_expr());
                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
                 }
+                ast::Effect::Const(_) => {
+                    let body = self.collect_block_opt(e.block_expr());
+                    self.alloc_expr(Expr::Const { body }, syntax_ptr)
+                }
             },
             ast::Expr::BlockExpr(e) => self.collect_block(e),
             ast::Expr::LoopExpr(e) => {
+                let label = e.label().map(|label| self.collect_label(label));
                 let body = self.collect_block_opt(e.loop_body());
-                self.alloc_expr(
-                    Expr::Loop {
-                        body,
-                        label: e.label().and_then(|l| l.lifetime()).map(|l| Name::new_lifetime(&l)),
-                    },
-                    syntax_ptr,
-                )
+                self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
             }
             ast::Expr::WhileExpr(e) => {
+                let label = e.label().map(|label| self.collect_label(label));
                 let body = self.collect_block_opt(e.loop_body());
 
                 let condition = match e.condition() {
@@ -279,42 +296,20 @@ impl ExprCollector<'_> {
                             ];
                             let match_expr =
                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
-                            return self.alloc_expr(
-                                Expr::Loop {
-                                    body: match_expr,
-                                    label: e
-                                        .label()
-                                        .and_then(|l| l.lifetime())
-                                        .map(|l| Name::new_lifetime(&l)),
-                                },
-                                syntax_ptr,
-                            );
+                            return self
+                                .alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr);
                         }
                     },
                 };
 
-                self.alloc_expr(
-                    Expr::While {
-                        condition,
-                        body,
-                        label: e.label().and_then(|l| l.lifetime()).map(|l| Name::new_lifetime(&l)),
-                    },
-                    syntax_ptr,
-                )
+                self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
             }
             ast::Expr::ForExpr(e) => {
+                let label = e.label().map(|label| self.collect_label(label));
                 let iterable = self.collect_expr_opt(e.iterable());
                 let pat = self.collect_pat_opt(e.pat());
                 let body = self.collect_block_opt(e.loop_body());
-                self.alloc_expr(
-                    Expr::For {
-                        iterable,
-                        pat,
-                        body,
-                        label: e.label().and_then(|l| l.lifetime()).map(|l| Name::new_lifetime(&l)),
-                    },
-                    syntax_ptr,
-                )
+                self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
             }
             ast::Expr::CallExpr(e) => {
                 let callee = self.collect_expr_opt(e.expr());
@@ -814,6 +809,13 @@ impl ExprCollector<'_> {
         }
     }
 
+    fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
+        let label = Label {
+            name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
+        };
+        self.alloc_label(label, AstPtr::new(&ast_label))
+    }
+
     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
         let pattern = match &pat {
             ast::Pat::IdentPat(bp) => {
@@ -932,6 +934,14 @@ impl ExprCollector<'_> {
                 let inner = self.collect_pat_opt(boxpat.pat());
                 Pat::Box { inner }
             }
+            ast::Pat::ConstBlockPat(const_block_pat) => {
+                if let Some(expr) = const_block_pat.block_expr() {
+                    let expr_id = self.collect_block(expr);
+                    Pat::ConstBlock(expr_id)
+                } else {
+                    Pat::Missing
+                }
+            }
             // FIXME: implement
             ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
         };
diff --git a/crates/hir_def/src/expr.rs b/crates/hir_def/src/expr.rs
index e5d740a36..6a481769d 100644
--- a/crates/hir_def/src/expr.rs
+++ b/crates/hir_def/src/expr.rs
@@ -30,6 +30,12 @@ pub(crate) fn dummy_expr_id() -> ExprId {
 pub type PatId = Idx<Pat>;
 
 #[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Label {
+    pub name: Name,
+}
+pub type LabelId = Idx<Label>;
+
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub enum Literal {
     String(String),
     ByteString(Vec<u8>),
@@ -52,22 +58,22 @@ pub enum Expr {
     Block {
         statements: Vec<Statement>,
         tail: Option<ExprId>,
-        label: Option<Name>,
+        label: Option<LabelId>,
     },
     Loop {
         body: ExprId,
-        label: Option<Name>,
+        label: Option<LabelId>,
     },
     While {
         condition: ExprId,
         body: ExprId,
-        label: Option<Name>,
+        label: Option<LabelId>,
     },
     For {
         iterable: ExprId,
         pat: PatId,
         body: ExprId,
-        label: Option<Name>,
+        label: Option<LabelId>,
     },
     Call {
         callee: ExprId,
@@ -114,6 +120,9 @@ pub enum Expr {
     Async {
         body: ExprId,
     },
+    Const {
+        body: ExprId,
+    },
     Cast {
         expr: ExprId,
         type_ref: TypeRef,
@@ -253,7 +262,10 @@ impl Expr {
                     f(*expr);
                 }
             }
-            Expr::TryBlock { body } | Expr::Unsafe { body } | Expr::Async { body } => f(*body),
+            Expr::TryBlock { body }
+            | Expr::Unsafe { body }
+            | Expr::Async { body }
+            | Expr::Const { body } => f(*body),
             Expr::Loop { body, .. } => f(*body),
             Expr::While { condition, body, .. } => {
                 f(*condition);
@@ -399,12 +411,18 @@ pub enum Pat {
     TupleStruct { path: Option<Path>, args: Vec<PatId>, ellipsis: Option<usize> },
     Ref { pat: PatId, mutability: Mutability },
     Box { inner: PatId },
+    ConstBlock(ExprId),
 }
 
 impl Pat {
     pub fn walk_child_pats(&self, mut f: impl FnMut(PatId)) {
         match self {
-            Pat::Range { .. } | Pat::Lit(..) | Pat::Path(..) | Pat::Wild | Pat::Missing => {}
+            Pat::Range { .. }
+            | Pat::Lit(..)
+            | Pat::Path(..)
+            | Pat::ConstBlock(..)
+            | Pat::Wild
+            | Pat::Missing => {}
             Pat::Bind { subpat, .. } => {
                 subpat.iter().copied().for_each(f);
             }
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 41134d23b..bb8fca009 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -62,6 +62,7 @@ pub struct GenericParams {
 pub enum WherePredicate {
     TypeBound { target: WherePredicateTypeTarget, bound: TypeBound },
     Lifetime { target: LifetimeRef, bound: LifetimeRef },
+    ForLifetime { lifetimes: Box<[Name]>, target: WherePredicateTypeTarget, bound: TypeBound },
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -69,7 +70,6 @@ pub enum WherePredicateTypeTarget {
     TypeRef(TypeRef),
     /// For desugared where predicates that can directly refer to a type param.
     TypeParam(LocalTypeParamId),
-    // FIXME: ForLifetime(Vec<LifetimeParamId>, TypeRef)
 }
 
 #[derive(Default)]
@@ -234,7 +234,7 @@ impl GenericParams {
         for bound in
             node.type_bound_list().iter().flat_map(|type_bound_list| type_bound_list.bounds())
         {
-            self.add_where_predicate_from_bound(lower_ctx, bound, target.clone());
+            self.add_where_predicate_from_bound(lower_ctx, bound, None, target.clone());
         }
     }
 
@@ -279,8 +279,25 @@ impl GenericParams {
             } else {
                 continue;
             };
+
+            let lifetimes: Option<Box<_>> = pred.generic_param_list().map(|param_list| {
+                // Higher-Ranked Trait Bounds
+                param_list
+                    .lifetime_params()
+                    .map(|lifetime_param| {
+                        lifetime_param
+                            .lifetime()
+                            .map_or_else(Name::missing, |lt| Name::new_lifetime(&lt))
+                    })
+                    .collect()
+            });
             for bound in pred.type_bound_list().iter().flat_map(|l| l.bounds()) {
-                self.add_where_predicate_from_bound(lower_ctx, bound, target.clone());
+                self.add_where_predicate_from_bound(
+                    lower_ctx,
+                    bound,
+                    lifetimes.as_ref(),
+                    target.clone(),
+                );
             }
         }
     }
@@ -289,6 +306,7 @@ impl GenericParams {
         &mut self,
         lower_ctx: &LowerCtx,
         bound: ast::TypeBound,
+        hrtb_lifetimes: Option<&Box<[Name]>>,
         target: Either<TypeRef, LifetimeRef>,
     ) {
         if bound.question_mark_token().is_some() {
@@ -297,9 +315,16 @@ impl GenericParams {
         }
         let bound = TypeBound::from_ast(lower_ctx, bound);
         let predicate = match (target, bound) {
-            (Either::Left(type_ref), bound) => WherePredicate::TypeBound {
-                target: WherePredicateTypeTarget::TypeRef(type_ref),
-                bound,
+            (Either::Left(type_ref), bound) => match hrtb_lifetimes {
+                Some(hrtb_lifetimes) => WherePredicate::ForLifetime {
+                    lifetimes: hrtb_lifetimes.clone(),
+                    target: WherePredicateTypeTarget::TypeRef(type_ref),
+                    bound,
+                },
+                None => WherePredicate::TypeBound {
+                    target: WherePredicateTypeTarget::TypeRef(type_ref),
+                    bound,
+                },
             },
             (Either::Right(lifetime), TypeBound::Lifetime(bound)) => {
                 WherePredicate::Lifetime { target: lifetime, bound }
diff --git a/crates/hir_def/src/nameres/mod_resolution.rs b/crates/hir_def/src/nameres/mod_resolution.rs
index b4ccd4488..af3262439 100644
--- a/crates/hir_def/src/nameres/mod_resolution.rs
+++ b/crates/hir_def/src/nameres/mod_resolution.rs
@@ -79,7 +79,7 @@ impl ModDir {
         for candidate in candidate_files.iter() {
             let path = AnchoredPath { anchor: file_id, path: candidate.as_str() };
             if let Some(file_id) = db.resolve_path(path) {
-                let is_mod_rs = candidate.ends_with("mod.rs");
+                let is_mod_rs = candidate.ends_with("/mod.rs");
 
                 let (dir_path, root_non_dir_owner) = if is_mod_rs || attr_path.is_some() {
                     (DirPath::empty(), false)
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index dddbbcdac..6382521fb 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -563,6 +563,7 @@ mod tests {
 
                 let args = macro_call.token_tree().unwrap();
                 let parsed_args = mbe::ast_to_token_tree(&args).unwrap().0;
+                let call_id = AstId::new(file_id.into(), ast_id_map.ast_id(&macro_call));
 
                 let arg_id = db.intern_eager_expansion({
                     EagerCallLoc {
@@ -570,7 +571,7 @@ mod tests {
                         fragment: FragmentKind::Expr,
                         subtree: Arc::new(parsed_args.clone()),
                         krate,
-                        file_id: file_id.into(),
+                        call: call_id,
                     }
                 });
 
@@ -580,7 +581,7 @@ mod tests {
                     fragment,
                     subtree: Arc::new(subtree),
                     krate,
-                    file_id: file_id.into(),
+                    call: call_id,
                 };
 
                 let id: MacroCallId = db.intern_eager_expansion(eager).into();
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index 4477d867f..077de3727 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -5,7 +5,7 @@ use std::sync::Arc;
 use base_db::{salsa, SourceDatabase};
 use mbe::{ExpandError, ExpandResult, MacroRules};
 use parser::FragmentKind;
-use syntax::{algo::diff, AstNode, GreenNode, Parse, SyntaxKind::*, SyntaxNode};
+use syntax::{algo::diff, ast::NameOwner, AstNode, GreenNode, Parse, SyntaxKind::*, SyntaxNode};
 
 use crate::{
     ast_id_map::AstIdMap, BuiltinDeriveExpander, BuiltinFnLikeExpander, EagerCallLoc, EagerMacroId,
@@ -129,11 +129,11 @@ fn ast_id_map(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<AstIdMap> {
 fn macro_def(db: &dyn AstDatabase, id: MacroDefId) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
     match id.kind {
         MacroDefKind::Declarative => {
-            let macro_call = match id.ast_id?.to_node(db) {
+            let macro_rules = match id.ast_id?.to_node(db) {
                 syntax::ast::Macro::MacroRules(mac) => mac,
                 syntax::ast::Macro::MacroDef(_) => return None,
             };
-            let arg = macro_call.token_tree()?;
+            let arg = macro_rules.token_tree()?;
             let (tt, tmap) = mbe::ast_to_token_tree(&arg).or_else(|| {
                 log::warn!("fail on macro_def to token tree: {:#?}", arg);
                 None
@@ -141,7 +141,8 @@ fn macro_def(db: &dyn AstDatabase, id: MacroDefId) -> Option<Arc<(TokenExpander,
             let rules = match MacroRules::parse(&tt) {
                 Ok(it) => it,
                 Err(err) => {
-                    log::warn!("fail on macro_def parse: error: {:#?} {:#?}", err, tt);
+                    let name = macro_rules.name().map(|n| n.to_string()).unwrap_or_default();
+                    log::warn!("fail on macro_def parse ({}): {:?} {:#?}", name, err, tt);
                     return None;
                 }
             };
diff --git a/crates/hir_expand/src/eager.rs b/crates/hir_expand/src/eager.rs
index 0229a836e..6354b090d 100644
--- a/crates/hir_expand/src/eager.rs
+++ b/crates/hir_expand/src/eager.rs
@@ -110,6 +110,9 @@ pub fn expand_eager_macro(
         || err("malformed macro invocation"),
     )?;
 
+    let ast_map = db.ast_id_map(macro_call.file_id);
+    let call_id = InFile::new(macro_call.file_id, ast_map.ast_id(&macro_call.value));
+
     // Note:
     // When `lazy_expand` is called, its *parent* file must be already exists.
     // Here we store an eager macro id for the argument expanded subtree here
@@ -120,7 +123,7 @@ pub fn expand_eager_macro(
             fragment: FragmentKind::Expr,
             subtree: Arc::new(parsed_args.clone()),
             krate,
-            file_id: macro_call.file_id,
+            call: call_id,
         }
     });
     let arg_file_id: MacroCallId = arg_id.into();
@@ -141,13 +144,8 @@ pub fn expand_eager_macro(
         let res = eager.expand(db, arg_id, &subtree);
 
         let (subtree, fragment) = diagnostic_sink.expand_result_option(res)?;
-        let eager = EagerCallLoc {
-            def,
-            fragment,
-            subtree: Arc::new(subtree),
-            krate,
-            file_id: macro_call.file_id,
-        };
+        let eager =
+            EagerCallLoc { def, fragment, subtree: Arc::new(subtree), krate, call: call_id };
 
         Ok(db.intern_eager_expansion(eager))
     } else {
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index d486186e5..3fa1b1d77 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -83,7 +83,7 @@ impl HirFileId {
                     }
                     MacroCallId::EagerMacro(id) => {
                         let loc = db.lookup_intern_eager_expansion(id);
-                        loc.file_id
+                        loc.call.file_id
                     }
                 };
                 file_id.original_file(db)
@@ -103,7 +103,7 @@ impl HirFileId {
                 }
                 MacroCallId::EagerMacro(id) => {
                     let loc = db.lookup_intern_eager_expansion(id);
-                    loc.file_id
+                    loc.call.file_id
                 }
             };
         }
@@ -114,17 +114,16 @@ impl HirFileId {
     pub fn call_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
         match self.0 {
             HirFileIdRepr::FileId(_) => None,
-            HirFileIdRepr::MacroFile(macro_file) => {
-                let lazy_id = match macro_file.macro_call_id {
-                    MacroCallId::LazyMacro(id) => id,
-                    MacroCallId::EagerMacro(_id) => {
-                        // FIXME: handle call node for eager macro
-                        return None;
-                    }
-                };
-                let loc = db.lookup_intern_macro(lazy_id);
-                Some(loc.kind.node(db))
-            }
+            HirFileIdRepr::MacroFile(macro_file) => match macro_file.macro_call_id {
+                MacroCallId::LazyMacro(lazy_id) => {
+                    let loc: MacroCallLoc = db.lookup_intern_macro(lazy_id);
+                    Some(loc.kind.node(db))
+                }
+                MacroCallId::EagerMacro(id) => {
+                    let loc: EagerCallLoc = db.lookup_intern_eager_expansion(id);
+                    Some(loc.call.with_value(loc.call.to_node(db).syntax().clone()))
+                }
+            },
         }
     }
 
@@ -304,7 +303,7 @@ pub struct EagerCallLoc {
     pub(crate) fragment: FragmentKind,
     pub(crate) subtree: Arc<tt::Subtree>,
     pub(crate) krate: CrateId,
-    pub(crate) file_id: HirFileId,
+    pub(crate) call: AstId<ast::MacroCall>,
 }
 
 /// ExpansionInfo mainly describes how to map text range between src and expanded macro
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 289e812fe..965c1780a 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -17,9 +17,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.43", default-features = false }
-chalk-ir = "0.43"
-chalk-recursive = "0.43"
+chalk-solve = { version = "0.45", default-features = false }
+chalk-ir = "0.45"
+chalk-recursive = "0.45"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 hir_def = { path = "../hir_def", version = "0.0.0" }
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 2cdce2cef..70a3f3075 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -143,7 +143,7 @@ impl<'a> InferenceContext<'a> {
                     self.breakables.push(BreakableContext {
                         may_break: false,
                         break_ty: break_ty.clone(),
-                        label: label.clone(),
+                        label: label.map(|label| self.body[label].name.clone()),
                     });
                     let ty = self.infer_block(statements, *tail, &Expectation::has_type(break_ty));
                     let ctxt = self.breakables.pop().expect("breakable stack broken");
@@ -155,7 +155,7 @@ impl<'a> InferenceContext<'a> {
                 }
                 None => self.infer_block(statements, *tail, expected),
             },
-            Expr::Unsafe { body } => self.infer_expr(*body, expected),
+            Expr::Unsafe { body } | Expr::Const { body } => self.infer_expr(*body, expected),
             Expr::TryBlock { body } => {
                 let _inner = self.infer_expr(*body, expected);
                 // FIXME should be std::result::Result<{inner}, _>
@@ -172,7 +172,7 @@ impl<'a> InferenceContext<'a> {
                 self.breakables.push(BreakableContext {
                     may_break: false,
                     break_ty: self.table.new_type_var(),
-                    label: label.clone(),
+                    label: label.map(|label| self.body[label].name.clone()),
                 });
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
 
@@ -191,7 +191,7 @@ impl<'a> InferenceContext<'a> {
                 self.breakables.push(BreakableContext {
                     may_break: false,
                     break_ty: Ty::Unknown,
-                    label: label.clone(),
+                    label: label.map(|label| self.body[label].name.clone()),
                 });
                 // while let is desugared to a match loop, so this is always simple while
                 self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
@@ -207,7 +207,7 @@ impl<'a> InferenceContext<'a> {
                 self.breakables.push(BreakableContext {
                     may_break: false,
                     break_ty: Ty::Unknown,
-                    label: label.clone(),
+                    label: label.map(|label| self.body[label].name.clone()),
                 });
                 let pat_ty =
                     self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
index b70ec55eb..d974f805b 100644
--- a/crates/hir_ty/src/infer/pat.rs
+++ b/crates/hir_ty/src/infer/pat.rs
@@ -243,6 +243,9 @@ impl<'a> InferenceContext<'a> {
                 }
                 None => Ty::Unknown,
             },
+            Pat::ConstBlock(expr) => {
+                self.infer_expr(*expr, &Expectation::has_type(expected.clone()))
+            }
             Pat::Missing => Ty::Unknown,
         };
         // use a new type variable if we got Ty::Unknown here
@@ -264,8 +267,9 @@ fn is_non_ref_pat(body: &hir_def::body::Body, pat: PatId) -> bool {
         | Pat::Range { .. }
         | Pat::Slice { .. } => true,
         Pat::Or(pats) => pats.iter().all(|p| is_non_ref_pat(body, *p)),
-        // FIXME: Path/Lit might actually evaluate to ref, but inference is unimplemented.
+        // FIXME: ConstBlock/Path/Lit might actually evaluate to ref, but inference is unimplemented.
         Pat::Path(..) => true,
+        Pat::ConstBlock(..) => true,
         Pat::Lit(expr) => match body[*expr] {
             Expr::Literal(Literal::String(..)) => false,
             _ => true,
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 8392cb770..8da56cd11 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -675,7 +675,8 @@ impl GenericPredicate {
         where_predicate: &'a WherePredicate,
     ) -> impl Iterator<Item = GenericPredicate> + 'a {
         match where_predicate {
-            WherePredicate::TypeBound { target, bound } => {
+            WherePredicate::ForLifetime { target, bound, .. }
+            | WherePredicate::TypeBound { target, bound } => {
                 let self_ty = match target {
                     WherePredicateTypeTarget::TypeRef(type_ref) => Ty::from_hir(ctx, type_ref),
                     WherePredicateTypeTarget::TypeParam(param_id) => {
@@ -888,14 +889,13 @@ pub(crate) fn generic_predicates_for_param_query(
         .where_predicates_in_scope()
         // we have to filter out all other predicates *first*, before attempting to lower them
         .filter(|pred| match pred {
-            WherePredicate::TypeBound {
-                target: WherePredicateTypeTarget::TypeRef(type_ref),
-                ..
-            } => Ty::from_hir_only_param(&ctx, type_ref) == Some(param_id),
-            WherePredicate::TypeBound {
-                target: WherePredicateTypeTarget::TypeParam(local_id),
-                ..
-            } => *local_id == param_id.local_id,
+            WherePredicate::ForLifetime { target, .. }
+            | WherePredicate::TypeBound { target, .. } => match target {
+                WherePredicateTypeTarget::TypeRef(type_ref) => {
+                    Ty::from_hir_only_param(&ctx, type_ref) == Some(param_id)
+                }
+                WherePredicateTypeTarget::TypeParam(local_id) => *local_id == param_id.local_id,
+            },
             WherePredicate::Lifetime { .. } => false,
         })
         .flat_map(|pred| {
diff --git a/crates/hir_ty/src/tests/patterns.rs b/crates/hir_ty/src/tests/patterns.rs
index 5a5f48fd0..2053d8f56 100644
--- a/crates/hir_ty/src/tests/patterns.rs
+++ b/crates/hir_ty/src/tests/patterns.rs
@@ -774,3 +774,33 @@ fn foo(tuple: Tuple) {
         "#]],
     );
 }
+
+#[test]
+fn const_block_pattern() {
+    check_infer(
+        r#"
+struct Foo(usize);
+fn foo(foo: Foo) {
+    match foo {
+        const { Foo(15 + 32) } => {},
+        _ => {}
+    }
+}"#,
+        expect![[r#"
+            26..29 'foo': Foo
+            36..115 '{     ...   } }': ()
+            42..113 'match ...     }': ()
+            48..51 'foo': Foo
+            62..84 'const ... 32) }': Foo
+            68..84 '{ Foo(... 32) }': Foo
+            70..73 'Foo': Foo(usize) -> Foo
+            70..82 'Foo(15 + 32)': Foo
+            74..76 '15': usize
+            74..81 '15 + 32': usize
+            79..81 '32': usize
+            88..90 '{}': ()
+            100..101 '_': Foo
+            105..107 '{}': ()
+        "#]],
+    );
+}
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index a569223b4..a61282d5a 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -1894,6 +1894,7 @@ fn effects_smoke_test() {
             let x = unsafe { 92 };
             let y = async { async { () }.await };
             let z = try { () };
+            let w = const { 92 };
             let t = 'a: { 92 };
         }
 
@@ -1905,7 +1906,7 @@ fn effects_smoke_test() {
         }
         "#,
         expect![[r#"
-            16..136 '{     ...2 }; }': ()
+            16..162 '{     ...2 }; }': ()
             26..27 'x': i32
             30..43 'unsafe { 92 }': i32
             37..43 '{ 92 }': i32
@@ -1921,9 +1922,13 @@ fn effects_smoke_test() {
             99..109 'try { () }': {unknown}
             103..109 '{ () }': ()
             105..107 '()': ()
-            119..120 't': i32
-            127..133 '{ 92 }': i32
-            129..131 '92': i32
+            119..120 'w': i32
+            123..135 'const { 92 }': i32
+            129..135 '{ 92 }': i32
+            131..133 '92': i32
+            145..146 't': i32
+            153..159 '{ 92 }': i32
+            155..157 '92': i32
         "#]],
     )
 }
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index 69eae6f79..2196af677 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -56,8 +56,13 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     fn adt_datum(&self, struct_id: AdtId) -> Arc<StructDatum> {
         self.db.struct_datum(self.krate, struct_id)
     }
-    fn adt_repr(&self, _struct_id: AdtId) -> rust_ir::AdtRepr {
-        rust_ir::AdtRepr { repr_c: false, repr_packed: false }
+    fn adt_repr(&self, _struct_id: AdtId) -> Arc<rust_ir::AdtRepr<Interner>> {
+        // FIXME: keep track of these
+        Arc::new(rust_ir::AdtRepr { c: false, packed: false, int: None })
+    }
+    fn discriminant_type(&self, _ty: chalk_ir::Ty<Interner>) -> chalk_ir::Ty<Interner> {
+        // FIXME: keep track of this
+        chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Uint(chalk_ir::UintTy::U32)).intern(&Interner)
     }
     fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum> {
         self.db.impl_datum(self.krate, impl_id)
@@ -457,6 +462,7 @@ fn well_known_trait_from_lang_attr(name: &str) -> Option<WellKnownTrait> {
         "fn" => WellKnownTrait::Fn,
         "unsize" => WellKnownTrait::Unsize,
         "coerce_unsized" => WellKnownTrait::CoerceUnsized,
+        "discriminant_kind" => WellKnownTrait::DiscriminantKind,
         _ => return None,
     })
 }
@@ -473,6 +479,7 @@ fn lang_attr_from_well_known_trait(attr: WellKnownTrait) -> &'static str {
         WellKnownTrait::Unsize => "unsize",
         WellKnownTrait::Unpin => "unpin",
         WellKnownTrait::CoerceUnsized => "coerce_unsized",
+        WellKnownTrait::DiscriminantKind => "discriminant_kind",
     }
 }
 
diff --git a/crates/hir_ty/src/utils.rs b/crates/hir_ty/src/utils.rs
index af880c065..65b79df0d 100644
--- a/crates/hir_ty/src/utils.rs
+++ b/crates/hir_ty/src/utils.rs
@@ -5,7 +5,9 @@ use std::sync::Arc;
 use hir_def::{
     adt::VariantData,
     db::DefDatabase,
-    generics::{GenericParams, TypeParamData, TypeParamProvenance, WherePredicateTypeTarget},
+    generics::{
+        GenericParams, TypeParamData, TypeParamProvenance, WherePredicate, WherePredicateTypeTarget,
+    },
     path::Path,
     resolver::{HasResolver, TypeNs},
     type_ref::TypeRef,
@@ -27,7 +29,8 @@ fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
         .where_predicates
         .iter()
         .filter_map(|pred| match pred {
-            hir_def::generics::WherePredicate::TypeBound { target, bound } => match target {
+            WherePredicate::ForLifetime { target, bound, .. }
+            | WherePredicate::TypeBound { target, bound } => match target {
                 WherePredicateTypeTarget::TypeRef(TypeRef::Path(p))
                     if p == &Path::from(name![Self]) =>
                 {
@@ -38,7 +41,7 @@ fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
                 }
                 _ => None,
             },
-            hir_def::generics::WherePredicate::Lifetime { .. } => None,
+            WherePredicate::Lifetime { .. } => None,
         })
         .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path.mod_path()) {
             Some(TypeNs::TraitId(t)) => Some(t),
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 049f808dc..038273750 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -248,35 +248,7 @@ mod tests {
     ///  * 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
-    pub(super) fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
-        let after = trim_indent(ra_fixture_after);
-
-        let (analysis, file_position) = fixture::position(ra_fixture_before);
-        let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), file_position.file_id)
-            .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.contains_inclusive(file_position.offset),
-            "diagnostic fix range {:?} does not touch cursor position {:?}",
-            fix.fix_trigger_range,
-            file_position.offset
-        );
-    }
-
-    /// Similar to `check_fix`, but applies all the available fixes.
-    fn check_fixes(ra_fixture_before: &str, ra_fixture_after: &str) {
+    pub(crate) fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
         let after = trim_indent(ra_fixture_after);
 
         let (analysis, file_position) = fixture::position(ra_fixture_before);
@@ -286,10 +258,12 @@ mod tests {
             .pop()
             .unwrap();
         let fix = diagnostic.fix.unwrap();
-        let target_file_contents = analysis.file_text(file_position.file_id).unwrap();
         let actual = {
-            let mut actual = target_file_contents.to_string();
+            let file_id = fix.source_change.source_file_edits.first().unwrap().file_id;
+            let mut actual = analysis.file_text(file_id).unwrap().to_string();
+
             // Go from the last one to the first one, so that ranges won't be affected by previous edits.
+            // FIXME: https://github.com/rust-analyzer/rust-analyzer/issues/4901#issuecomment-644675309
             for edit in fix.source_change.source_file_edits.iter().rev() {
                 edit.edit.apply(&mut actual);
             }
@@ -305,29 +279,6 @@ mod tests {
         );
     }
 
-    /// 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) = fixture::position(ra_fixture_before);
-        let current_file_id = file_pos.file_id;
-        let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), current_file_id)
-            .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.
     pub(crate) fn check_no_diagnostics(ra_fixture: &str) {
@@ -619,6 +570,7 @@ fn test_fn() {
                                                 ),
                                                 path: "foo.rs",
                                             },
+                                            initial_contents: "",
                                         },
                                     ],
                                     is_snippet: false,
@@ -763,25 +715,25 @@ struct Foo {
 
     #[test]
     fn test_add_field_in_other_file_from_usage() {
-        check_apply_diagnostic_fix_in_other_file(
-            r"
-            //- /main.rs
-            mod foo;
+        check_fix(
+            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
-            }
-            ",
+fn main() {
+    foo::Foo { bar: 3, <|>baz: false};
+}
+//- /foo.rs
+struct Foo {
+    bar: i32
+}
+"#,
+            r#"
+struct Foo {
+    bar: i32,
+    pub(crate) baz: bool
+}
+"#,
         )
     }
 
@@ -801,7 +753,7 @@ struct Foo {
 
     #[test]
     fn test_rename_incorrect_case() {
-        check_fixes(
+        check_fix(
             r#"
 pub struct test_struct<|> { one: i32 }
 
@@ -818,7 +770,7 @@ pub fn some_fn(val: TestStruct) -> TestStruct {
 "#,
         );
 
-        check_fixes(
+        check_fix(
             r#"
 pub fn some_fn(NonSnakeCase<|>: u8) -> u8 {
     NonSnakeCase
@@ -831,7 +783,7 @@ pub fn some_fn(non_snake_case: u8) -> u8 {
 "#,
         );
 
-        check_fixes(
+        check_fix(
             r#"
 pub fn SomeFn<|>(val: u8) -> u8 {
     if val != 0 { SomeFn(val - 1) } else { val }
@@ -844,7 +796,7 @@ pub fn some_fn(val: u8) -> u8 {
 "#,
         );
 
-        check_fixes(
+        check_fix(
             r#"
 fn some_fn() {
     let whatAWeird_Formatting<|> = 10;
@@ -873,7 +825,7 @@ fn foo() {
 
     #[test]
     fn test_rename_incorrect_case_struct_method() {
-        check_fixes(
+        check_fix(
             r#"
 pub struct TestStruct;
 
@@ -894,4 +846,17 @@ impl TestStruct {
 "#,
         );
     }
+
+    #[test]
+    fn test_single_incorrect_case_diagnostic_in_function_name_issue_6970() {
+        let input = r#"fn FOO<|>() {}"#;
+        let expected = r#"fn foo() {}"#;
+
+        let (analysis, file_position) = fixture::position(input);
+        let diagnostics =
+            analysis.diagnostics(&DiagnosticsConfig::default(), file_position.file_id).unwrap();
+        assert_eq!(diagnostics.len(), 1);
+
+        check_fix(input, expected);
+    }
 }
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index e8b896623..d79f5c170 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -40,6 +40,7 @@ impl DiagnosticWithFix for UnresolvedModule {
                     anchor: self.file.original_file(sema.db),
                     path: self.candidate.clone(),
                 },
+                initial_contents: "".to_string(),