26 files changed, 7186 insertions, 463 deletions

diff --git a/crates/ide_completion/Cargo.toml b/crates/ide_completion/Cargo.toml
index c09101ccb..585ecca50 100644
--- a/crates/ide_completion/Cargo.toml
+++ b/crates/ide_completion/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 itertools = "0.10.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
@@ -21,11 +22,11 @@ text_edit = { path = "../text_edit", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 # completions crate should depend only on the top-level `hir` package. if you need
 # something from some `hir_xxx` subpackage, reexport the API via `hir`.
 hir = { path = "../hir", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide_completion/src/completions/attribute.rs b/crates/ide_completion/src/completions/attribute.rs
index 3a5bc4381..e846678b4 100644
--- a/crates/ide_completion/src/completions/attribute.rs
+++ b/crates/ide_completion/src/completions/attribute.rs
@@ -39,20 +39,21 @@ pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext)
 }
 
 fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attribute: &ast::Attr) {
-    for attr_completion in ATTRIBUTES {
+    let is_inner = attribute.kind() == ast::AttrKind::Inner;
+    for attr_completion in ATTRIBUTES.iter().filter(|compl| is_inner || !compl.prefer_inner) {
         let mut item = CompletionItem::new(
             CompletionKind::Attribute,
             ctx.source_range(),
             attr_completion.label,
-        )
-        .kind(CompletionItemKind::Attribute);
+        );
+        item.kind(CompletionItemKind::Attribute);
 
         if let Some(lookup) = attr_completion.lookup {
-            item = item.lookup_by(lookup);
+            item.lookup_by(lookup);
         }
 
         if let Some((snippet, cap)) = attr_completion.snippet.zip(ctx.config.snippet_cap) {
-            item = item.insert_snippet(cap, snippet);
+            item.insert_snippet(cap, snippet);
         }
 
         if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
@@ -167,16 +168,20 @@ fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input:
             );
             let lookup = components.join(", ");
             let label = components.iter().rev().join(", ");
-            CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label)
-                .lookup_by(lookup)
-                .kind(CompletionItemKind::Attribute)
-                .add_to(acc)
+            let mut item =
+                CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label);
+            item.lookup_by(lookup).kind(CompletionItemKind::Attribute);
+            item.add_to(acc);
         }
 
         for custom_derive_name in get_derive_names_in_scope(ctx).difference(&existing_derives) {
-            CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), custom_derive_name)
-                .kind(CompletionItemKind::Attribute)
-                .add_to(acc)
+            let mut item = CompletionItem::new(
+                CompletionKind::Attribute,
+                ctx.source_range(),
+                custom_derive_name,
+            );
+            item.kind(CompletionItemKind::Attribute);
+            item.add_to(acc);
         }
     }
 }
@@ -192,14 +197,13 @@ fn complete_lint(
             .into_iter()
             .filter(|completion| !existing_lints.contains(completion.label))
         {
-            CompletionItem::new(
+            let mut item = CompletionItem::new(
                 CompletionKind::Attribute,
                 ctx.source_range(),
                 lint_completion.label,
-            )
-            .kind(CompletionItemKind::Attribute)
-            .detail(lint_completion.description)
-            .add_to(acc)
+            );
+            item.kind(CompletionItemKind::Attribute).detail(lint_completion.description);
+            item.add_to(acc)
         }
     }
 }
diff --git a/crates/ide_completion/src/completions/dot.rs b/crates/ide_completion/src/completions/dot.rs
index 084d7721d..5ee9a9f07 100644
--- a/crates/ide_completion/src/completions/dot.rs
+++ b/crates/ide_completion/src/completions/dot.rs
@@ -2,7 +2,6 @@
 
 use hir::{HasVisibility, Type};
 use rustc_hash::FxHashSet;
-use test_utils::mark;
 
 use crate::{context::CompletionContext, Completions};
 
@@ -19,7 +18,7 @@ pub(crate) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     };
 
     if ctx.is_call {
-        mark::hit!(test_no_struct_field_completion_for_method_call);
+        cov_mark::hit!(test_no_struct_field_completion_for_method_call);
     } else {
         complete_fields(acc, ctx, &receiver_ty);
     }
@@ -62,7 +61,6 @@ fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &T
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{test_utils::completion_list, CompletionKind};
 
@@ -122,7 +120,7 @@ impl A {
 
     #[test]
     fn test_no_struct_field_completion_for_method_call() {
-        mark::check!(test_no_struct_field_completion_for_method_call);
+        cov_mark::check!(test_no_struct_field_completion_for_method_call);
         check(
             r#"
 struct A { the_field: u32 }
diff --git a/crates/ide_completion/src/completions/flyimport.rs b/crates/ide_completion/src/completions/flyimport.rs
index da8375af9..391a11c91 100644
--- a/crates/ide_completion/src/completions/flyimport.rs
+++ b/crates/ide_completion/src/completions/flyimport.rs
@@ -21,6 +21,46 @@
 //! ```
 //!
 //! Also completes associated items, that require trait imports.
+//! If any unresolved and/or partially-qualified path predeces the input, it will be taken into account.
+//! Currently, only the imports with their import path ending with the whole qialifier will be proposed
+//! (no fuzzy matching for qualifier).
+//!
+//! ```
+//! mod foo {
+//!     pub mod bar {
+//!         pub struct Item;
+//!
+//!         impl Item {
+//!             pub const TEST_ASSOC: usize = 3;
+//!         }
+//!     }
+//! }
+//!
+//! fn main() {
+//!     bar::Item::TEST_A$0
+//! }
+//! ```
+//! ->
+//! ```
+//! use foo::bar;
+//!
+//! mod foo {
+//!     pub mod bar {
+//!         pub struct Item;
+//!
+//!         impl Item {
+//!             pub const TEST_ASSOC: usize = 3;
+//!         }
+//!     }
+//! }
+//!
+//! fn main() {
+//!     bar::Item::TEST_ASSOC
+//! }
+//! ```
+//!
+//! NOTE: currently, if an assoc item comes from a trait that's not currently imported and it also has an unresolved and/or partially-qualified path,
+//! no imports will be proposed.
 //!
 //! .Fuzzy search details
 //!
@@ -48,14 +88,13 @@
 //! Note that having this flag set to `true` does not guarantee that the feature is enabled: your client needs to have the corredponding
 //! capability enabled.
 
-use hir::{AsAssocItem, ModPath, ScopeDef};
+use hir::ModPath;
 use ide_db::helpers::{
     import_assets::{ImportAssets, ImportCandidate},
     insert_use::ImportScope,
 };
-use rustc_hash::FxHashSet;
+use itertools::Itertools;
 use syntax::{AstNode, SyntaxNode, T};
-use test_utils::mark;
 
 use crate::{
     context::CompletionContext,
@@ -93,50 +132,26 @@ pub(crate) fn import_on_the_fly(acc: &mut Completions, ctx: &CompletionContext)
         &ctx.sema,
     )?;
 
-    let scope_definitions = scope_definitions(ctx);
-    let mut all_mod_paths = import_assets
-        .search_for_imports(&ctx.sema, ctx.config.insert_use.prefix_kind)
-        .into_iter()
-        .map(|(mod_path, item_in_ns)| {
-            let scope_item = match item_in_ns {
-                hir::ItemInNs::Types(id) => ScopeDef::ModuleDef(id.into()),
-                hir::ItemInNs::Values(id) => ScopeDef::ModuleDef(id.into()),
-                hir::ItemInNs::Macros(id) => ScopeDef::MacroDef(id.into()),
-            };
-            (mod_path, scope_item)
-        })
-        .filter(|(_, proposed_def)| !scope_definitions.contains(proposed_def))
-        .collect::<Vec<_>>();
-    all_mod_paths.sort_by_cached_key(|(mod_path, _)| {
-        compute_fuzzy_completion_order_key(mod_path, &user_input_lowercased)
-    });
-
-    acc.add_all(all_mod_paths.into_iter().filter_map(|(import_path, definition)| {
-        let import_for_trait_assoc_item = match definition {
-            ScopeDef::ModuleDef(module_def) => module_def
-                .as_assoc_item(ctx.db)
-                .and_then(|assoc| assoc.containing_trait(ctx.db))
-                .is_some(),
-            _ => false,
-        };
-        let import_edit = ImportEdit {
-            import_path,
-            import_scope: import_scope.clone(),
-            import_for_trait_assoc_item,
-        };
-        render_resolution_with_import(RenderContext::new(ctx), import_edit, &definition)
-    }));
+    acc.add_all(
+        import_assets
+            .search_for_imports(&ctx.sema, ctx.config.insert_use.prefix_kind)
+            .into_iter()
+            .sorted_by_key(|located_import| {
+                compute_fuzzy_completion_order_key(
+                    &located_import.import_path,
+                    &user_input_lowercased,
+                )
+            })
+            .filter_map(|import| {
+                render_resolution_with_import(
+                    RenderContext::new(ctx),
+                    ImportEdit { import, scope: import_scope.clone() },
+                )
+            }),
+    );
     Some(())
 }
 
-fn scope_definitions(ctx: &CompletionContext) -> FxHashSet<ScopeDef> {
-    let mut scope_definitions = FxHashSet::default();
-    ctx.scope.process_all_names(&mut |_, scope_def| {
-        scope_definitions.insert(scope_def);
-    });
-    scope_definitions
-}
-
 pub(crate) fn position_for_import<'a>(
     ctx: &'a CompletionContext,
     import_candidate: Option<&ImportCandidate>,
@@ -161,23 +176,30 @@ fn import_assets(ctx: &CompletionContext, fuzzy_name: String) -> Option<ImportAs
             current_module,
             ctx.sema.type_of_expr(dot_receiver)?,
             fuzzy_name,
+            dot_receiver.syntax().clone(),
         )
     } else {
         let fuzzy_name_length = fuzzy_name.len();
+        let approximate_node = match current_module.definition_source(ctx.db).value {
+            hir::ModuleSource::SourceFile(s) => s.syntax().clone(),
+            hir::ModuleSource::Module(m) => m.syntax().clone(),
+            hir::ModuleSource::BlockExpr(b) => b.syntax().clone(),
+        };
         let assets_for_path = ImportAssets::for_fuzzy_path(
             current_module,
             ctx.path_qual.clone(),
             fuzzy_name,
             &ctx.sema,
-        );
+            approximate_node,
+        )?;
 
-        if matches!(assets_for_path.as_ref()?.import_candidate(), ImportCandidate::Path(_))
+        if matches!(assets_for_path.import_candidate(), ImportCandidate::Path(_))
             && fuzzy_name_length < 2
         {
-            mark::hit!(ignore_short_input_for_path);
+            cov_mark::hit!(ignore_short_input_for_path);
             None
         } else {
-            assets_for_path
+            Some(assets_for_path)
         }
     }
 }
@@ -186,12 +208,12 @@ fn compute_fuzzy_completion_order_key(
     proposed_mod_path: &ModPath,
     user_input_lowercased: &str,
 ) -> usize {
-    mark::hit!(certain_fuzzy_order_test);
-    let proposed_import_name = match proposed_mod_path.segments().last() {
+    cov_mark::hit!(certain_fuzzy_order_test);
+    let import_name = match proposed_mod_path.segments().last() {
         Some(name) => name.to_string().to_lowercase(),
         None => return usize::MAX,
     };
-    match proposed_import_name.match_indices(user_input_lowercased).next() {
+    match import_name.match_indices(user_input_lowercased).next() {
         Some((first_matching_index, _)) => first_matching_index,
         None => usize::MAX,
     }
@@ -200,7 +222,6 @@ fn compute_fuzzy_completion_order_key(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         item::CompletionKind,
@@ -295,7 +316,7 @@ fn main() {
 
     #[test]
     fn short_paths_are_ignored() {
-        mark::check!(ignore_short_input_for_path);
+        cov_mark::check!(ignore_short_input_for_path);
 
         check(
             r#"
@@ -319,7 +340,7 @@ fn main() {
 
     #[test]
     fn fuzzy_completions_come_in_specific_order() {
-        mark::check!(certain_fuzzy_order_test);
+        cov_mark::check!(certain_fuzzy_order_test);
         check(
             r#"
 //- /lib.rs crate:dep
@@ -775,4 +796,155 @@ fn main() {
 }"#,
         );
     }
+
+    #[test]
+    fn unresolved_qualifier() {
+        let fixture = r#"
+mod foo {
+    pub mod bar {
+        pub mod baz {
+            pub struct Item;
+        }
+    }
+}
+
+fn main() {
+    bar::baz::Ite$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        st foo::bar::baz::Item
+        "#]],
+        );
+
+        check_edit(
+            "Item",
+            fixture,
+            r#"
+        use foo::bar;
+
+        mod foo {
+            pub mod bar {
+                pub mod baz {
+                    pub struct Item;
+                }
+            }
+        }
+
+        fn main() {
+            bar::baz::Item
+        }"#,
+        );
+    }
+
+    #[test]
+    fn unresolved_assoc_item_container() {
+        let fixture = r#"
+mod foo {
+    pub struct Item;
+
+    impl Item {
+        pub const TEST_ASSOC: usize = 3;
+    }
+}
+
+fn main() {
+    Item::TEST_A$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        ct TEST_ASSOC (foo::Item)
+        "#]],
+        );
+
+        check_edit(
+            "TEST_ASSOC",
+            fixture,
+            r#"
+use foo::Item;
+
+mod foo {
+    pub struct Item;
+
+    impl Item {
+        pub const TEST_ASSOC: usize = 3;
+    }
+}
+
+fn main() {
+    Item::TEST_ASSOC
+}"#,
+        );
+    }
+
+    #[test]
+    fn unresolved_assoc_item_container_with_path() {
+        let fixture = r#"
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Item::TEST_A$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        ct TEST_ASSOC (foo::bar::Item)
+    "#]],
+        );
+
+        check_edit(
+            "TEST_ASSOC",
+            fixture,
+            r#"
+use foo::bar;
+
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Item::TEST_ASSOC
+}"#,
+        );
+    }
+
+    #[test]
+    fn fuzzy_unresolved_path() {
+        check(
+            r#"
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Ass$0
+}"#,
+            expect![[]],
+        )
+    }
 }
diff --git a/crates/ide_completion/src/completions/fn_param.rs b/crates/ide_completion/src/completions/fn_param.rs
index 38e33a93e..0243dce56 100644
--- a/crates/ide_completion/src/completions/fn_param.rs
+++ b/crates/ide_completion/src/completions/fn_param.rs
@@ -25,9 +25,12 @@ pub(crate) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
             return;
         }
         func.param_list().into_iter().flat_map(|it| it.params()).for_each(|param| {
-            let text = param.syntax().text().to_string();
-            params.entry(text).or_insert(param);
-        })
+            if let Some(pat) = param.pat() {
+                let text = param.syntax().text().to_string();
+                let lookup = pat.syntax().text().to_string();
+                params.entry(text).or_insert(lookup);
+            }
+        });
     };
 
     for node in ctx.token.parent().ancestors() {
@@ -50,18 +53,11 @@ pub(crate) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
         };
     }
 
-    params
-        .into_iter()
-        .filter_map(|(label, param)| {
-            let lookup = param.pat()?.syntax().text().to_string();
-            Some((label, lookup))
-        })
-        .for_each(|(label, lookup)| {
-            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
-                .kind(CompletionItemKind::Binding)
-                .lookup_by(lookup)
-                .add_to(acc)
-        });
+    params.into_iter().for_each(|(label, lookup)| {
+        let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label);
+        item.kind(CompletionItemKind::Binding).lookup_by(lookup);
+        item.add_to(acc)
+    });
 }
 
 #[cfg(test)]
diff --git a/crates/ide_completion/src/completions/keyword.rs b/crates/ide_completion/src/completions/keyword.rs
index eb81f9765..b635e0ca3 100644
--- a/crates/ide_completion/src/completions/keyword.rs
+++ b/crates/ide_completion/src/completions/keyword.rs
@@ -1,7 +1,8 @@
 //! Completes keywords.
 
+use std::iter;
+
 use syntax::SyntaxKind;
-use test_utils::mark;
 
 use crate::{CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions};
 
@@ -11,29 +12,30 @@ pub(crate) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
 
     if ctx.use_item_syntax.is_some() {
         if ctx.path_qual.is_none() {
-            CompletionItem::new(CompletionKind::Keyword, source_range, "crate::")
-                .kind(CompletionItemKind::Keyword)
-                .insert_text("crate::")
-                .add_to(acc);
+            let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "crate::");
+            item.kind(CompletionItemKind::Keyword).insert_text("crate::");
+            item.add_to(acc);
+        }
+        let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "self");
+        item.kind(CompletionItemKind::Keyword);
+        item.add_to(acc);
+        if iter::successors(ctx.path_qual.clone(), |p| p.qualifier())
+            .all(|p| p.segment().and_then(|s| s.super_token()).is_some())
+        {
+            let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "super::");
+            item.kind(CompletionItemKind::Keyword).insert_text("super::");
+            item.add_to(acc);
         }
-        CompletionItem::new(CompletionKind::Keyword, source_range, "self")
-            .kind(CompletionItemKind::Keyword)
-            .add_to(acc);
-        CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
-            .kind(CompletionItemKind::Keyword)
-            .insert_text("super::")
-            .add_to(acc);
     }
 
     // Suggest .await syntax for types that implement Future trait
     if let Some(receiver) = &ctx.dot_receiver {
         if let Some(ty) = ctx.sema.type_of_expr(receiver) {
             if ty.impls_future(ctx.db) {
-                CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
-                    .kind(CompletionItemKind::Keyword)
-                    .detail("expr.await")
-                    .insert_text("await")
-                    .add_to(acc);
+                let mut item =
+                    CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await");
+                item.kind(CompletionItemKind::Keyword).detail("expr.await").insert_text("await");
+                item.add_to(acc);
             }
         };
     }
@@ -41,11 +43,11 @@ pub(crate) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
 
 pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionContext) {
     if ctx.token.kind() == SyntaxKind::COMMENT {
-        mark::hit!(no_keyword_completion_in_comments);
+        cov_mark::hit!(no_keyword_completion_in_comments);
         return;
     }
     if ctx.record_lit_syntax.is_some() {
-        mark::hit!(no_keyword_completion_in_record_lit);
+        cov_mark::hit!(no_keyword_completion_in_record_lit);
         return;
     }
 
@@ -85,6 +87,7 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
     if ctx.is_expr {
         add_keyword(ctx, acc, "match", "match $0 {}");
         add_keyword(ctx, acc, "while", "while $0 {}");
+        add_keyword(ctx, acc, "while let", "while let $1 = $0 {}");
         add_keyword(ctx, acc, "loop", "loop {$0}");
         add_keyword(ctx, acc, "if", "if $0 {}");
         add_keyword(ctx, acc, "if let", "if let $1 = $0 {}");
@@ -159,29 +162,31 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
 }
 
 fn add_keyword(ctx: &CompletionContext, acc: &mut Completions, kw: &str, snippet: &str) {
-    let builder = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw)
-        .kind(CompletionItemKind::Keyword);
-    let builder = match ctx.config.snippet_cap {
+    let mut item = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw);
+    item.kind(CompletionItemKind::Keyword);
+
+    match ctx.config.snippet_cap {
         Some(cap) => {
             let tmp;
             let snippet = if snippet.ends_with('}') && ctx.incomplete_let {
-                mark::hit!(let_semi);
+                cov_mark::hit!(let_semi);
                 tmp = format!("{};", snippet);
                 &tmp
             } else {
                 snippet
             };
-            builder.insert_snippet(cap, snippet)
+            item.insert_snippet(cap, snippet);
+        }
+        None => {
+            item.insert_text(if snippet.contains('$') { kw } else { snippet });
         }
-        None => builder.insert_text(if snippet.contains('$') { kw } else { snippet }),
     };
-    acc.add(builder.build());
+    item.add_to(acc);
 }
 
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list},
@@ -204,9 +209,17 @@ mod tests {
             "#]],
         );
 
+        // FIXME: `self` shouldn't be shown here and the check below
         check(
             r"use a::$0",
             expect![[r#"
+            kw self
+        "#]],
+        );
+
+        check(
+            r"use super::$0",
+            expect![[r#"
                 kw self
                 kw super::
             "#]],
@@ -215,9 +228,8 @@ mod tests {
         check(
             r"use a::{b, $0}",
             expect![[r#"
-                kw self
-                kw super::
-            "#]],
+            kw self
+        "#]],
         );
     }
 
@@ -256,6 +268,7 @@ mod tests {
                 kw trait
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -283,6 +296,7 @@ mod tests {
                 kw trait
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -310,6 +324,7 @@ mod tests {
                 kw trait
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -344,6 +359,7 @@ fn quux() -> i32 {
             expect![[r#"
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -393,6 +409,7 @@ fn quux() -> i32 {
                 kw trait
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -475,7 +492,7 @@ fn quux() -> i32 {
 
     #[test]
     fn no_keyword_completion_in_comments() {
-        mark::check!(no_keyword_completion_in_comments);
+        cov_mark::check!(no_keyword_completion_in_comments);
         check(
             r#"
 fn test() {
@@ -552,6 +569,7 @@ pub mod future {
             expect![[r#"
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -579,7 +597,7 @@ struct Foo {
 
     #[test]
     fn skip_struct_initializer() {
-        mark::check!(no_keyword_completion_in_record_lit);
+        cov_mark::check!(no_keyword_completion_in_record_lit);
         check(
             r#"
 struct Foo {
@@ -611,6 +629,7 @@ fn foo() {
             expect![[r#"
                 kw match
                 kw while
+                kw while let
                 kw loop
                 kw if
                 kw if let
@@ -622,7 +641,7 @@ fn foo() {
 
     #[test]
     fn let_semi() {
-        mark::check!(let_semi);
+        cov_mark::check!(let_semi);
         check_edit(
             "match",
             r#"
diff --git a/crates/ide_completion/src/completions/mod_.rs b/crates/ide_completion/src/completions/mod_.rs
index 352fc7c77..4f9415736 100644
--- a/crates/ide_completion/src/completions/mod_.rs
+++ b/crates/ide_completion/src/completions/mod_.rs
@@ -80,9 +80,9 @@ pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Op
             if mod_under_caret.semicolon_token().is_none() {
                 label.push(';');
             }
-            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), &label)
-                .kind(SymbolKind::Module)
-                .add_to(acc)
+            let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), &label);
+            item.kind(SymbolKind::Module);
+            item.add_to(acc)
         });
 
     Some(())
diff --git a/crates/ide_completion/src/completions/postfix.rs b/crates/ide_completion/src/completions/postfix.rs
index 9c34ed0b6..ac69b720a 100644
--- a/crates/ide_completion/src/completions/postfix.rs
+++ b/crates/ide_completion/src/completions/postfix.rs
@@ -187,6 +187,16 @@ pub(crate) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         ctx,
         cap,
         &dot_receiver,
+        "err",
+        "Err(expr)",
+        &format!("Err({})", receiver_text),
+    )
+    .add_to(acc);
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
         "some",
         "Some(expr)",
         &format!("Some({})", receiver_text),
@@ -287,10 +297,9 @@ fn postfix_snippet(
         let delete_range = TextRange::new(receiver_range.start(), ctx.source_range().end());
         TextEdit::replace(delete_range, snippet.to_string())
     };
-    CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label)
-        .detail(detail)
-        .kind(CompletionItemKind::Snippet)
-        .snippet_edit(cap, edit)
+    let mut item = CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label);
+    item.detail(detail).kind(CompletionItemKind::Snippet).snippet_edit(cap, edit);
+    item
 }
 
 #[cfg(test)]
@@ -325,6 +334,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -357,6 +367,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -380,6 +391,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -408,6 +420,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
diff --git a/crates/ide_completion/src/completions/qualified_path.rs b/crates/ide_completion/src/completions/qualified_path.rs
index 2afa6979e..df74b739e 100644
--- a/crates/ide_completion/src/completions/qualified_path.rs
+++ b/crates/ide_completion/src/completions/qualified_path.rs
@@ -3,7 +3,6 @@
 use hir::{Adt, HasVisibility, PathResolution, ScopeDef};
 use rustc_hash::FxHashSet;
 use syntax::AstNode;
-use test_utils::mark;
 
 use crate::{CompletionContext, Completions};
 
@@ -39,7 +38,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                         if let Some(name_ref) = ctx.name_ref_syntax.as_ref() {
                             if name_ref.syntax().text() == name.to_string().as_str() {
                                 // for `use self::foo$0`, don't suggest `foo` as a completion
-                                mark::hit!(dont_complete_current_use);
+                                cov_mark::hit!(dont_complete_current_use);
                                 continue;
                             }
                         }
@@ -81,9 +80,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                         return None;
                     }
                     match item {
-                        hir::AssocItem::Function(func) => {
-                            acc.add_function(ctx, func, None);
-                        }
+                        hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
                         hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
                         hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
                     }
@@ -110,9 +107,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     continue;
                 }
                 match item {
-                    hir::AssocItem::Function(func) => {
-                        acc.add_function(ctx, func, None);
-                    }
+                    hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
                     hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
                     hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
                 }
@@ -143,9 +138,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                     // them.
                     if seen.insert(item) {
                         match item {
-                            hir::AssocItem::Function(func) => {
-                                acc.add_function(ctx, func, None);
-                            }
+                            hir::AssocItem::Function(func) => acc.add_function(ctx, func, None),
                             hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
                             hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
                         }
@@ -161,7 +154,6 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list},
@@ -180,7 +172,7 @@ mod tests {
 
     #[test]
     fn dont_complete_current_use() {
-        mark::check!(dont_complete_current_use);
+        cov_mark::check!(dont_complete_current_use);
         check(r#"use self::foo$0;"#, expect![[""]]);
     }
 
diff --git a/crates/ide_completion/src/completions/record.rs b/crates/ide_completion/src/completions/record.rs
index 0a7927eb8..2f95b8687 100644
--- a/crates/ide_completion/src/completions/record.rs
+++ b/crates/ide_completion/src/completions/record.rs
@@ -22,16 +22,13 @@ pub(crate) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) ->
                 let completion_text = completion_text
                     .strip_prefix(ctx.token.to_string().as_str())
                     .unwrap_or(completion_text);
-                acc.add(
-                    CompletionItem::new(
-                        CompletionKind::Snippet,
-                        ctx.source_range(),
-                        "..Default::default()",
-                    )
-                    .insert_text(completion_text)
-                    .kind(SymbolKind::Field)
-                    .build(),
+                let mut item = CompletionItem::new(
+                    CompletionKind::Snippet,
+                    ctx.source_range(),
+                    "..Default::default()",
                 );
+                item.insert_text(completion_text).kind(SymbolKind::Field);
+                item.add_to(acc);
             }
 
             missing_fields
diff --git a/crates/ide_completion/src/completions/snippet.rs b/crates/ide_completion/src/completions/snippet.rs
index df17a15c5..7f7830976 100644
--- a/crates/ide_completion/src/completions/snippet.rs
+++ b/crates/ide_completion/src/completions/snippet.rs
@@ -8,9 +8,9 @@ use crate::{
 };
 
 fn snippet(ctx: &CompletionContext, cap: SnippetCap, label: &str, snippet: &str) -> Builder {
-    CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label)
-        .insert_snippet(cap, snippet)
-        .kind(CompletionItemKind::Snippet)
+    let mut item = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label);
+    item.insert_snippet(cap, snippet).kind(CompletionItemKind::Snippet);
+    item
 }
 
 pub(crate) fn complete_expr_snippet(acc: &mut Completions, ctx: &CompletionContext) {
@@ -35,7 +35,7 @@ pub(crate) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionConte
         None => return,
     };
 
-    snippet(
+    let mut item = snippet(
         ctx,
         cap,
         "tmod (Test module)",
@@ -49,11 +49,11 @@ mod tests {
         $0
     }
 }",
-    )
-    .lookup_by("tmod")
-    .add_to(acc);
+    );
+    item.lookup_by("tmod");
+    item.add_to(acc);
 
-    snippet(
+    let mut item = snippet(
         ctx,
         cap,
         "tfn (Test function)",
@@ -62,11 +62,12 @@ mod tests {
 fn ${1:feature}() {
     $0
 }",
-    )
-    .lookup_by("tfn")
-    .add_to(acc);
+    );
+    item.lookup_by("tfn");
+    item.add_to(acc);
 
-    snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}").add_to(acc);
+    let item = snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}");
+    item.add_to(acc);
 }
 
 #[cfg(test)]
diff --git a/crates/ide_completion/src/completions/trait_impl.rs b/crates/ide_completion/src/completions/trait_impl.rs
index b999540b8..5a7361f8e 100644
--- a/crates/ide_completion/src/completions/trait_impl.rs
+++ b/crates/ide_completion/src/completions/trait_impl.rs
@@ -145,9 +145,8 @@ fn add_function_impl(
         format!("fn {}(..)", fn_name)
     };
 
-    let builder = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
-        .lookup_by(fn_name)
-        .set_documentation(func.docs(ctx.db));
+    let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label);
+    item.lookup_by(fn_name).set_documentation(func.docs(ctx.db));
 
     let completion_kind = if func.self_param(ctx.db).is_some() {
         CompletionItemKind::Method
@@ -161,15 +160,15 @@ fn add_function_impl(
         match ctx.config.snippet_cap {
             Some(cap) => {
                 let snippet = format!("{} {{\n    $0\n}}", function_decl);
-                builder.snippet_edit(cap, TextEdit::replace(range, snippet))
+                item.snippet_edit(cap, TextEdit::replace(range, snippet));
             }
             None => {
                 let header = format!("{} {{", function_decl);
-                builder.text_edit(TextEdit::replace(range, header))
+                item.text_edit(TextEdit::replace(range, header));
             }
-        }
-        .kind(completion_kind)
-        .add_to(acc);
+        };
+        item.kind(completion_kind);
+        item.add_to(acc);
     }
 }
 
@@ -185,12 +184,12 @@ fn add_type_alias_impl(
 
     let range = TextRange::new(type_def_node.text_range().start(), ctx.source_range().end());
 
-    CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
-        .text_edit(TextEdit::replace(range, snippet))
+    let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone());
+    item.text_edit(TextEdit::replace(range, snippet))
         .lookup_by(alias_name)
         .kind(SymbolKind::TypeAlias)
-        .set_documentation(type_alias.docs(ctx.db))
-        .add_to(acc);
+        .set_documentation(type_alias.docs(ctx.db));
+    item.add_to(acc);
 }
 
 fn add_const_impl(
@@ -208,12 +207,13 @@ fn add_const_impl(
             let range =
                 TextRange::new(const_def_node.text_range().start(), ctx.source_range().end());
 
-            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
-                .text_edit(TextEdit::replace(range, snippet))
+            let mut item =
+                CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone());
+            item.text_edit(TextEdit::replace(range, snippet))
                 .lookup_by(const_name)
                 .kind(SymbolKind::Const)
-                .set_documentation(const_.docs(ctx.db))
-                .add_to(acc);
+                .set_documentation(const_.docs(ctx.db));
+            item.add_to(acc);
         }
     }
 }
diff --git a/crates/ide_completion/src/completions/unqualified_path.rs b/crates/ide_completion/src/completions/unqualified_path.rs
index e9d0ff665..044dfd160 100644
--- a/crates/ide_completion/src/completions/unqualified_path.rs
+++ b/crates/ide_completion/src/completions/unqualified_path.rs
@@ -2,7 +2,6 @@
 
 use hir::ScopeDef;
 use syntax::AstNode;
-use test_utils::mark;
 
 use crate::{CompletionContext, Completions};
 
@@ -30,13 +29,13 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
 
     ctx.scope.process_all_names(&mut |name, res| {
         if let ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) = res {
-            mark::hit!(skip_lifetime_completion);
+            cov_mark::hit!(skip_lifetime_completion);
             return;
         }
         if ctx.use_item_syntax.is_some() {
             if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
                 if name_ref.syntax().text() == name.to_string().as_str() {
-                    mark::hit!(self_fulfilling_completion);
+                    cov_mark::hit!(self_fulfilling_completion);
                     return;
                 }
             }
@@ -48,7 +47,6 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list_with_config, TEST_CONFIG},
@@ -66,7 +64,7 @@ mod tests {
 
     #[test]
     fn self_fulfilling_completion() {
-        mark::check!(self_fulfilling_completion);
+        cov_mark::check!(self_fulfilling_completion);
         check(
             r#"
 use foo$0
@@ -185,7 +183,7 @@ fn quux() {
 
     #[test]
     fn completes_if_prefix_is_keyword() {
-        mark::check!(completes_if_prefix_is_keyword);
+        cov_mark::check!(completes_if_prefix_is_keyword);
         check_edit(
             "wherewolf",
             r#"
@@ -223,7 +221,7 @@ fn main() {
 
     #[test]
     fn does_not_complete_lifetimes() {
-        mark::check!(skip_lifetime_completion);
+        cov_mark::check!(skip_lifetime_completion);
         check(
             r#"fn quux<'a>() { $0 }"#,
             expect![[r#"
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 3db357855..17d9a3adf 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -7,7 +7,7 @@ use syntax::{
     algo::find_node_at_offset, ast, match_ast, AstNode, NodeOrToken, SyntaxKind::*, SyntaxNode,
     SyntaxToken, TextRange, TextSize,
 };
-use test_utils::mark;
+
 use text_edit::Indel;
 
 use crate::{
@@ -240,7 +240,7 @@ impl<'a> CompletionContext<'a> {
         // check kind of macro-expanded token, but use range of original token
         let kind = self.token.kind();
         if kind == IDENT || kind == UNDERSCORE || kind.is_keyword() {
-            mark::hit!(completes_if_prefix_is_keyword);
+            cov_mark::hit!(completes_if_prefix_is_keyword);
             self.original_token.text_range()
         } else {
             TextRange::empty(self.position.offset)
diff --git a/crates/ide_completion/src/generated_lint_completions.rs b/crates/ide_completion/src/generated_lint_completions.rs
index 87df7f1c9..0d405350d 100644
--- a/crates/ide_completion/src/generated_lint_completions.rs
+++ b/crates/ide_completion/src/generated_lint_completions.rs
@@ -1,5 +1,6380 @@
 //! Generated file, do not edit by hand, see `xtask/src/codegen`
 
 use crate::completions::attribute::LintCompletion;