Repository: rust-analyzer/rust-analyzer
Pull request #9041 (2021-05-28 20:19:28)

internal: Implement prev sibling determination for `CompletionContext `
bors r+


Patch:
diff --git a/crates/base_db/src/fixture.rs b/crates/base_db/src/fixture.rs
index 0132565e47..69ceba7356 100644
--- a/crates/base_db/src/fixture.rs
+++ b/crates/base_db/src/fixture.rs
@@ -34,19 +34,13 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
 
     fn with_position(ra_fixture: &str) -> (Self, FilePosition) {
         let (db, file_id, range_or_offset) = Self::with_range_or_offset(ra_fixture);
-        let offset = match range_or_offset {
-            RangeOrOffset::Range(_) => panic!("Expected a cursor position, got a range instead"),
-            RangeOrOffset::Offset(it) => it,
-        };
+        let offset = range_or_offset.expect_offset();
         (db, FilePosition { file_id, offset })
     }
 
     fn with_range(ra_fixture: &str) -> (Self, FileRange) {
         let (db, file_id, range_or_offset) = Self::with_range_or_offset(ra_fixture);
-        let range = match range_or_offset {
-            RangeOrOffset::Range(it) => it,
-            RangeOrOffset::Offset(_) => panic!("Expected a cursor range, got a position instead"),
-        };
+        let range = range_or_offset.expect_range();
         (db, FileRange { file_id, range })
     }
 
diff --git a/crates/ide/src/fixture.rs b/crates/ide/src/fixture.rs
index cc6641ba13..6780af6172 100644
--- a/crates/ide/src/fixture.rs
+++ b/crates/ide/src/fixture.rs
@@ -1,7 +1,7 @@
 //! Utilities for creating `Analysis` instances for tests.
 use ide_db::base_db::fixture::ChangeFixture;
 use syntax::{TextRange, TextSize};
-use test_utils::{extract_annotations, RangeOrOffset};
+use test_utils::extract_annotations;
 
 use crate::{Analysis, AnalysisHost, FileId, FilePosition, FileRange};
 
@@ -27,10 +27,7 @@ pub(crate) fn position(ra_fixture: &str) -> (Analysis, FilePosition) {
     let change_fixture = ChangeFixture::parse(ra_fixture);
     host.db.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let offset = match range_or_offset {
-        RangeOrOffset::Range(_) => panic!(),
-        RangeOrOffset::Offset(it) => it,
-    };
+    let offset = range_or_offset.expect_offset();
     (host.analysis(), FilePosition { file_id, offset })
 }
 
@@ -40,10 +37,7 @@ pub(crate) fn range(ra_fixture: &str) -> (Analysis, FileRange) {
     let change_fixture = ChangeFixture::parse(ra_fixture);
     host.db.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let range = match range_or_offset {
-        RangeOrOffset::Range(it) => it,
-        RangeOrOffset::Offset(_) => panic!(),
-    };
+    let range = range_or_offset.expect_range();
     (host.analysis(), FileRange { file_id, range })
 }
 
@@ -53,10 +47,7 @@ pub(crate) fn annotations(ra_fixture: &str) -> (Analysis, FilePosition, Vec<(Fil
     let change_fixture = ChangeFixture::parse(ra_fixture);
     host.db.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let offset = match range_or_offset {
-        RangeOrOffset::Range(_) => panic!(),
-        RangeOrOffset::Offset(it) => it,
-    };
+    let offset = range_or_offset.expect_offset();
 
     let annotations = change_fixture
         .files
diff --git a/crates/ide_completion/src/completions/keyword.rs b/crates/ide_completion/src/completions/keyword.rs
index c9673df85d..e71a04b6ec 100644
--- a/crates/ide_completion/src/completions/keyword.rs
+++ b/crates/ide_completion/src/completions/keyword.rs
@@ -48,91 +48,92 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
         cov_mark::hit!(no_keyword_completion_in_record_lit);
         return;
     }
+    let mut add_keyword = |kw, snippet| add_keyword(ctx, acc, kw, snippet);
 
     let expects_assoc_item = ctx.expects_assoc_item();
     let has_block_expr_parent = ctx.has_block_expr_parent();
     let expects_item = ctx.expects_item();
+
     if ctx.has_impl_or_trait_prev_sibling() {
-        add_keyword(ctx, acc, "where", "where ");
+        // FIXME this also incorrectly shows up after a complete trait/impl
+        add_keyword("where", "where ");
         return;
     }
     if ctx.previous_token_is(T![unsafe]) {
-        if expects_item || has_block_expr_parent {
-            add_keyword(ctx, acc, "fn", "fn $1($2) {\n    $0\n}")
+        if expects_item || expects_assoc_item || has_block_expr_parent {
+            add_keyword("fn", "fn $1($2) {\n    $0\n}")
         }
 
         if expects_item || has_block_expr_parent {
-            add_keyword(ctx, acc, "trait", "trait $1 {\n    $0\n}");
-            add_keyword(ctx, acc, "impl", "impl $1 {\n    $0\n}");
+            add_keyword("trait", "trait $1 {\n    $0\n}");
+            add_keyword("impl", "impl $1 {\n    $0\n}");
         }
 
         return;
     }
+
+    if expects_item || ctx.expects_non_trait_assoc_item() || ctx.expect_record_field() {
+        add_keyword("pub(crate)", "pub(crate) ");
+        add_keyword("pub", "pub ");
+    }
+
+    if expects_item || expects_assoc_item || has_block_expr_parent || ctx.is_match_arm {
+        add_keyword("unsafe", "unsafe ");
+    }
+
     if expects_item || expects_assoc_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "fn", "fn $1($2) {\n    $0\n}");
+        add_keyword("fn", "fn $1($2) {\n    $0\n}");
+        add_keyword("const", "const $0");
+        add_keyword("type", "type $0");
     }
+
     if expects_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "use", "use ");
-        add_keyword(ctx, acc, "impl", "impl $1 {\n    $0\n}");
-        add_keyword(ctx, acc, "trait", "trait $1 {\n    $0\n}");
+        add_keyword("use", "use $0");
+        add_keyword("impl", "impl $1 {\n    $0\n}");
+        add_keyword("trait", "trait $1 {\n    $0\n}");
+        add_keyword("static", "static $0");
+        add_keyword("extern", "extern $0");
+        add_keyword("mod", "mod $0");
     }
 
     if expects_item {
-        add_keyword(ctx, acc, "enum", "enum $1 {\n    $0\n}");
-        add_keyword(ctx, acc, "struct", "struct $0");
-        add_keyword(ctx, acc, "union", "union $1 {\n    $0\n}");
+        add_keyword("enum", "enum $1 {\n    $0\n}");
+        add_keyword("struct", "struct $0");
+        add_keyword("union", "union $1 {\n    $0\n}");
     }
 
-    if ctx.is_expr {
-        add_keyword(ctx, acc, "match", "match $1 {\n    $0\n}");
-        add_keyword(ctx, acc, "while", "while $1 {\n    $0\n}");
-        add_keyword(ctx, acc, "while let", "while let $1 = $2 {\n    $0\n}");
-        add_keyword(ctx, acc, "loop", "loop {\n    $0\n}");
-        add_keyword(ctx, acc, "if", "if $1 {\n    $0\n}");
-        add_keyword(ctx, acc, "if let", "if let $1 = $2 {\n    $0\n}");
-        add_keyword(ctx, acc, "for", "for $1 in $2 {\n    $0\n}");
+    if ctx.expects_expression() {
+        add_keyword("match", "match $1 {\n    $0\n}");
+        add_keyword("while", "while $1 {\n    $0\n}");
+        add_keyword("while let", "while let $1 = $2 {\n    $0\n}");
+        add_keyword("loop", "loop {\n    $0\n}");
+        add_keyword("if", "if $1 {\n    $0\n}");
+        add_keyword("if let", "if let $1 = $2 {\n    $0\n}");
+        add_keyword("for", "for $1 in $2 {\n    $0\n}");
     }
 
     if ctx.previous_token_is(T![if]) || ctx.previous_token_is(T![while]) || has_block_expr_parent {
-        add_keyword(ctx, acc, "let", "let ");
+        add_keyword("let", "let ");
     }
 
-    if ctx.after_if {
-        add_keyword(ctx, acc, "else", "else {\n    $0\n}");
-        add_keyword(ctx, acc, "else if", "else if $1 {\n    $0\n}");
-    }
-    if expects_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "mod", "mod $0");
+    if ctx.after_if() {
+        add_keyword("else", "else {\n    $0\n}");
+        add_keyword("else if", "else if $1 {\n    $0\n}");
     }
+
     if ctx.expects_ident_pat_or_ref_expr() {
-        add_keyword(ctx, acc, "mut", "mut ");
-    }
-    if expects_item || expects_assoc_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "const", "const ");
-        add_keyword(ctx, acc, "type", "type ");
-    }
-    if expects_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "static", "static ");
-    };
-    if expects_item || has_block_expr_parent {
-        add_keyword(ctx, acc, "extern", "extern ");
-    }
-    if expects_item || expects_assoc_item || has_block_expr_parent || ctx.is_match_arm {
-        add_keyword(ctx, acc, "unsafe", "unsafe ");
+        add_keyword("mut", "mut ");
     }
+
     if ctx.in_loop_body {
         if ctx.can_be_stmt {
-            add_keyword(ctx, acc, "continue", "continue;");
-            add_keyword(ctx, acc, "break", "break;");
+            add_keyword("continue", "continue;");
+            add_keyword("break", "break;");
         } else {
-            add_keyword(ctx, acc, "continue", "continue");
-            add_keyword(ctx, acc, "break", "break");
+            add_keyword("continue", "continue");
+            add_keyword("break", "break");
         }
     }
-    if expects_item || ctx.expects_non_trait_assoc_item() || ctx.expect_record_field() {
-        add_keyword(ctx, acc, "pub(crate)", "pub(crate) ");
-        add_keyword(ctx, acc, "pub", "pub ");
-    }
 
     if !ctx.is_trivial_path {
         return;
@@ -143,8 +144,6 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
     };
 
     add_keyword(
-        ctx,
-        acc,
         "return",
         match (ctx.can_be_stmt, fn_def.ret_type().is_some()) {
             (true, true) => "return $0;",
@@ -161,15 +160,12 @@ fn add_keyword(ctx: &CompletionContext, acc: &mut Completions, kw: &str, snippet
 
     match ctx.config.snippet_cap {
         Some(cap) => {
-            let tmp;
-            let snippet = if snippet.ends_with('}') && ctx.incomplete_let {
+            if snippet.ends_with('}') && ctx.incomplete_let {
                 cov_mark::hit!(let_semi);
-                tmp = format!("{};", snippet);
-                &tmp
+                item.insert_snippet(cap, format!("{};", snippet));
             } else {
-                snippet
-            };
-            item.insert_snippet(cap, snippet);
+                item.insert_snippet(cap, snippet);
+            }
         }
         None => {
             item.insert_text(if snippet.contains('$') { kw } else { snippet });
@@ -232,21 +228,21 @@ mod tests {
         check(
             r"m$0",
             expect![[r#"
+                kw pub(crate)
+                kw pub
+                kw unsafe
                 kw fn
+                kw const
+                kw type
                 kw use
                 kw impl
                 kw trait
+                kw static
+                kw extern
+                kw mod
                 kw enum
                 kw struct
                 kw union
-                kw mod
-                kw const
-                kw type
-                kw static
-                kw extern
-                kw unsafe
-                kw pub(crate)
-                kw pub
             "#]],
         );
     }
@@ -256,10 +252,16 @@ mod tests {
         check(
             r"fn quux() { $0 }",
             expect![[r#"
+                kw unsafe
                 kw fn
+                kw const
+                kw type
                 kw use
                 kw impl
                 kw trait
+                kw static
+                kw extern
+                kw mod
                 kw match
                 kw while
                 kw while let
@@ -268,12 +270,6 @@ mod tests {
                 kw if let
                 kw for
                 kw let
-                kw mod
-                kw const
-                kw type
-                kw static
-                kw extern
-                kw unsafe
                 kw return
             "#]],
         );
@@ -284,10 +280,16 @@ mod tests {
         check(
             r"fn quux() { if true { $0 } }",
             expect![[r#"
+                kw unsafe
                 kw fn
+                kw const
+                kw type
                 kw use
                 kw impl
                 kw trait
+                kw static
+                kw extern
+                kw mod
                 kw match
                 kw while
                 kw while let
@@ -296,12 +298,6 @@ mod tests {
                 kw if let
                 kw for
                 kw let
-                kw mod
-                kw const
-                kw type
-                kw static
-                kw extern
-                kw unsafe
                 kw return
             "#]],
         );
@@ -312,10 +308,16 @@ mod tests {
         check(
             r#"fn quux() { if true { () } $0 }"#,
             expect![[r#"
+                kw unsafe
                 kw fn
+                kw const
+                kw type
                 kw use
                 kw impl
                 kw trait
+                kw static
+                kw extern
+                kw mod
                 kw match
                 kw while
                 kw while let
@@ -326,12 +328,6 @@ mod tests {
                 kw let
                 kw else
                 kw else if
-                kw mod
-                kw const
-                kw type
-                kw static
-                kw extern
-                kw unsafe
                 kw return
             "#]],
         );
@@ -353,6 +349,7 @@ fn quux() -> i32 {
 }
 "#,
             expect![[r#"
+                kw unsafe
                 kw match
                 kw while
                 kw while let
@@ -360,7 +357,6 @@ fn quux() -> i32 {
                 kw if
                 kw if let
                 kw for
-                kw unsafe
                 kw return
             "#]],
         );
@@ -371,10 +367,10 @@ fn quux() -> i32 {
         check(
             r"trait My { $0 }",
             expect![[r#"
+                kw unsafe
                 kw fn
                 kw const
                 kw type
-                kw unsafe
             "#]],
         );
     }
@@ -384,12 +380,12 @@ fn quux() -> i32 {
         check(
             r"impl My { $0 }",
             expect![[r#"
+                kw pub(crate)
+                kw pub
+                kw unsafe
                 kw fn
                 kw const
                 kw type
-                kw unsafe
-                kw pub(crate)
-                kw pub
             "#]],
         );
     }
@@ -399,12 +395,12 @@ fn quux() -> i32 {
         check(
             r"impl My { #[foo] $0 }",
             expect![[r#"
+                kw pub(crate)
+                kw pub
+                kw unsafe
                 kw fn
                 kw const
                 kw type
-                kw unsafe
-                kw pub(crate)
-                kw pub
             "#]],
         );
     }
@@ -414,10 +410,16 @@ fn quux() -> i32 {
         check(
             r"fn my() { loop { $0 } }",
             expect![[r#"
+                kw unsafe
                 kw fn
+                kw const
+                kw type
                 kw use
                 kw impl
                 kw trait
+                kw static
+                kw extern
+                kw mod
                 kw match
                 kw while
                 kw while let
@@ -426,12 +428,6 @@ fn quux() -> i32 {
                 kw if let
                 kw for
                 kw let
-                kw mod
-                kw const
-                kw type
-                kw static
-                kw extern
-                kw unsafe
                 kw continue
                 kw break
                 kw return
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 923e35dbb9..8d6440cb23 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -17,8 +17,8 @@ use text_edit::Indel;
 
 use crate::{
     patterns::{
-        determine_location, for_is_prev2, has_prev_sibling, inside_impl_trait_block,
-        is_in_loop_body, is_match_arm, previous_token, ImmediateLocation,
+        determine_location, determine_prev_sibling, for_is_prev2, inside_impl_trait_block,
+        is_in_loop_body, is_match_arm, previous_token, ImmediateLocation, ImmediatePrevSibling,
     },
     CompletionConfig,
 };
@@ -29,12 +29,6 @@ pub(crate) enum PatternRefutability {
     Irrefutable,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub(crate) enum PrevSibling {
-    Trait,
-    Impl,
-}
-
 /// `CompletionContext` is created early during completion to figure out, where
 /// exactly is the cursor, syntax-wise.
 #[derive(Debug)]
@@ -76,6 +70,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) is_param: bool,
 
     pub(super) completion_location: Option<ImmediateLocation>,
+    pub(super) prev_sibling: Option<ImmediatePrevSibling>,
 
     /// FIXME: `ActiveParameter` is string-based, which is very very wrong
     pub(super) active_parameter: Option<ActiveParameter>,
@@ -83,7 +78,6 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) is_trivial_path: bool,
     /// If not a trivial path, the prefix (qualifier).
     pub(super) path_qual: Option<ast::Path>,
-    pub(super) after_if: bool,
     /// `true` if we are a statement or a last expr in the block.
     pub(super) can_be_stmt: bool,
     /// `true` if we expect an expression at the cursor position.
@@ -107,7 +101,6 @@ pub(crate) struct CompletionContext<'a> {
 
     // keyword patterns
     pub(super) previous_token: Option<SyntaxToken>,
-    pub(super) prev_sibling: Option<PrevSibling>,
     pub(super) in_loop_body: bool,
     pub(super) is_match_arm: bool,
     pub(super) incomplete_let: bool,
@@ -173,7 +166,6 @@ impl<'a> CompletionContext<'a> {
             is_pat_or_const: None,
             is_trivial_path: false,
             path_qual: None,
-            after_if: false,
             can_be_stmt: false,
             is_expr: false,
             is_new_item: false,
@@ -288,6 +280,10 @@ impl<'a> CompletionContext<'a> {
         matches!(self.completion_location, Some(ImmediateLocation::ItemList))
     }
 
+    pub(crate) fn expects_expression(&self) -> bool {
+        self.is_expr
+    }
+
     pub(crate) fn has_block_expr_parent(&self) -> bool {
         matches!(self.completion_location, Some(ImmediateLocation::BlockExpr))
     }
@@ -304,7 +300,14 @@ impl<'a> CompletionContext<'a> {
     }
 
     pub(crate) fn has_impl_or_trait_prev_sibling(&self) -> bool {
-        self.prev_sibling.is_some()
+        matches!(
+            self.prev_sibling,
+            Some(ImmediatePrevSibling::ImplDefType) | Some(ImmediatePrevSibling::TraitDefName)
+        )
+    }
+
+    pub(crate) fn after_if(&self) -> bool {
+        matches!(self.prev_sibling, Some(ImmediatePrevSibling::IfExpr))
     }
 
     pub(crate) fn is_path_disallowed(&self) -> bool {
@@ -316,15 +319,10 @@ impl<'a> CompletionContext<'a> {
 
     fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) {
         let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap();
-        let syntax_element = NodeOrToken::Token(fake_ident_token.clone());
+        let syntax_element = NodeOrToken::Token(fake_ident_token);
         self.previous_token = previous_token(syntax_element.clone());
         self.in_loop_body = is_in_loop_body(syntax_element.clone());
         self.is_match_arm = is_match_arm(syntax_element.clone());
-        if has_prev_sibling(syntax_element.clone(), IMPL) {
-            self.prev_sibling = Some(PrevSibling::Impl)
-        } else if has_prev_sibling(syntax_element.clone(), TRAIT) {
-            self.prev_sibling = Some(PrevSibling::Trait)
-        }
 
         self.mod_declaration_under_caret =
             find_node_at_offset::<ast::Module>(&file_with_fake_ident, offset)
@@ -338,8 +336,6 @@ impl<'a> CompletionContext<'a> {
         let fn_is_prev = self.previous_token_is(T![fn]);
         let for_is_prev2 = for_is_prev2(syntax_element.clone());
         self.no_completion_required = (fn_is_prev && !inside_impl_trait_block) || for_is_prev2;
-
-        self.completion_location = determine_location(fake_ident_token);
     }
 
     fn fill_impl_def(&mut self) {
@@ -465,6 +461,8 @@ impl<'a> CompletionContext<'a> {
             Some(it) => it,
             None => return,
         };
+        self.completion_location = determine_location(&name_like);
+        self.prev_sibling = determine_prev_sibling(&name_like);
         match name_like {
             ast::NameLike::Lifetime(lifetime) => {
                 self.classify_lifetime(original_file, lifetime, offset);
@@ -653,17 +651,6 @@ impl<'a> CompletionContext<'a> {
                 })
                 .unwrap_or(false);
             self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
-
-            if let Some(off) = name_ref.syntax().text_range().start().checked_sub(2.into()) {
-                if let Some(if_expr) =
-                    self.sema.find_node_at_offset_with_macros::<ast::IfExpr>(original_file, off)
-                {
-                    if if_expr.syntax().text_range().end() < name_ref.syntax().text_range().start()
-                    {
-                        self.after_if = true;
-                    }
-                }
-            }
         }
 
         if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) {
diff --git a/crates/ide_completion/src/patterns.rs b/crates/ide_completion/src/patterns.rs
index c8a88367d7..caf0ef39fc 100644
--- a/crates/ide_completion/src/patterns.rs
+++ b/crates/ide_completion/src/patterns.rs
@@ -4,12 +4,19 @@ use syntax::{
     algo::non_trivia_sibling,
     ast::{self, LoopBodyOwner},
     match_ast, AstNode, Direction, NodeOrToken, SyntaxElement,
-    SyntaxKind::{self, *},
+    SyntaxKind::*,
     SyntaxNode, SyntaxToken, T,
 };
 
 #[cfg(test)]
 use crate::test_utils::{check_pattern_is_applicable, check_pattern_is_not_applicable};
+/// Direct parent container of the cursor position
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub(crate) enum ImmediatePrevSibling {
+    IfExpr,
+    TraitDefName,
+    ImplDefType,
+}
 
 /// Direct parent container of the cursor position
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
@@ -24,35 +31,61 @@ pub(crate) enum ImmediateLocation {
     ItemList,
 }
 
-pub(crate) fn determine_location(tok: SyntaxToken) -> Option<ImmediateLocation> {
-    // First walk the element we are completing up to its highest node that has the same text range
-    // as the element so that we can check in what context it immediately lies. We only do this for
-    // NameRef -> Path as that's the only thing that makes sense to being "expanded" semantically.
-    // We only wanna do this if the NameRef is the last segment of the path.
-    let node = match tok.parent().and_then(ast::NameLike::cast)? {
-        ast::NameLike::NameRef(name_ref) => {
-            if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
-                let p = segment.parent_path();
-                if p.parent_path().is_none() {
-                    p.syntax()
-                        .ancestors()
-                        .take_while(|it| it.text_range() == p.syntax().text_range())
-                        .last()?
-                } else {
-                    return None;
+pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
+    let node = maximize_name_ref(name_like)?;
+    let node = match node.parent().and_then(ast::MacroCall::cast) {
+        // When a path is being typed after the name of a trait/type of an impl it is being
+        // parsed as a macro, so when the trait/impl has a block following it an we are between the
+        // name and block the macro will attach the block to itself so maximizing fails to take
+        // that into account
+        // FIXME path expr and statement have a similar problem with attrs
+        Some(call)
+            if call.excl_token().is_none()
+                && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
+                && call.semicolon_token().is_none() =>
+        {
+            call.syntax().clone()
+        }
+        _ => node,
+    };
+    let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
+    let res = match_ast! {
+        match prev_sibling {
+            ast::ExprStmt(it) => {
+                let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
+                match_ast! {
+                    match node {
+                        ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
+                        _ => return None,
+                    }
                 }
-            } else {
-                return None;
-            }
+            },
+            ast::Trait(it) => if it.assoc_item_list().is_none() {
+                    ImmediatePrevSibling::TraitDefName
+                } else {
+                    return None
+            },
+            ast::Impl(it) => if it.assoc_item_list().is_none()
+                && (it.for_token().is_none() || it.self_ty().is_some()) {
+                    ImmediatePrevSibling::ImplDefType
+                } else {
+                    return None
+            },
+            _ => return None,
         }
-        it @ ast::NameLike::Name(_) | it @ ast::NameLike::Lifetime(_) => it.syntax().clone(),
     };
+    Some(res)
+}
+
+pub(crate) fn determine_location(name_like: &ast::NameLike) -> Option<ImmediateLocation> {
+    let node = maximize_name_ref(name_like)?;
     let parent = match node.parent() {
         Some(parent) => match ast::MacroCall::cast(parent.clone()) {
             // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
             // This is usually fine as the node expansion code above already accounts for that with
             // the ancestors call, but there is one exception to this which is that when an attribute
             // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
+            // FIXME path expr and statement have a similar problem
             Some(call)
                 if call.excl_token().is_none()
                     && call.token_tree().is_none()
@@ -90,56 +123,30 @@ pub(crate) fn determine_location(tok: SyntaxToken) -> Option<ImmediateLocation>
     Some(res)
 }
 
-#[cfg(test)]
-fn check_location(code: &str, loc: ImmediateLocation) {
-    check_pattern_is_applicable(code, |e| {
-        assert_eq!(determine_location(e.into_token().expect("Expected a token")), Some(loc));
-        true
-    });
-}
-
-#[test]
-fn test_has_trait_parent() {
-    check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
-}
-
-#[test]
-fn test_has_use_parent() {
-    check_location(r"use f$0", ImmediateLocation::Use);
-}
-
-#[test]
-fn test_has_impl_parent() {
-    check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
-}
-#[test]
-fn test_has_field_list_parent() {
-    check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
-    check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
-}
-
-#[test]
-fn test_has_block_expr_parent() {
-    check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
-}
-
-#[test]
-fn test_has_ident_pat_parent() {
-    check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
-    check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
-    check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
-    check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
-}
-
-#[test]
-fn test_has_ref_expr_parent() {
-    check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
-}
-
-#[test]
-fn test_has_item_list_or_source_file_parent() {
-    check_location(r"i$0", ImmediateLocation::ItemList);
-    check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
+fn maximize_name_ref(name_like: &ast::NameLike) -> Option<SyntaxNode> {
+    // First walk the element we are completing up to its highest node that has the same text range
+    // as the element so that we can check in what context it immediately lies. We only do this for
+    // NameRef -> Path as that's the only thing that makes sense to being "expanded" semantically.
+    // We only wanna do this if the NameRef is the last segment of the path.
+    let node = match name_like {
+        ast::NameLike::NameRef(name_ref) => {
+            if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
+                let p = segment.parent_path();
+                if p.parent_path().is_none() {
+                    p.syntax()
+                        .ancestors()
+                        .take_while(|it| it.text_range() == p.syntax().text_range())
+                        .last()?
+                } else {
+                    return None;
+                }
+            } else {
+                return None;
+            }
+        }
+        it @ ast::NameLike::Name(_) | it @ ast::NameLike::Lifetime(_) => it.syntax().clone(),
+    };
+    Some(node)
 }
 
 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
@@ -191,14 +198,6 @@ fn test_for_is_prev2() {
     check_pattern_is_applicable(r"for i i$0", for_is_prev2);
 }
 
-pub(crate) fn has_prev_sibling(element: SyntaxElement, kind: SyntaxKind) -> bool {
-    previous_sibling_or_ancestor_sibling(element).filter(|it| it.kind() == kind).is_some()
-}
-#[test]
-fn test_has_impl_as_prev_sibling() {
-    check_pattern_is_applicable(r"impl A w$0 {}", |it| has_prev_sibling(it, IMPL));
-}
-
 pub(crate) fn is_in_loop_body(element: SyntaxElement) -> bool {
     element
         .ancestors()
@@ -247,3 +246,111 @@ fn previous_sibling_or_ancestor_sibling(element: SyntaxElement) -> Option<Syntax
         non_trivia_sibling(NodeOrToken::Node(prev_sibling_node), Direction::Prev)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
+        check_pattern_is_applicable(code, |e| {
+            let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
+            assert_eq!(determine_location(name), loc.into());
+            true
+        });
+    }
+
+    fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
+        check_pattern_is_applicable(code, |e| {
+            let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
+            assert_eq!(determine_prev_sibling(name), sibling.into());
+            true
+        });
+    }
+
+    #[test]
+    fn test_trait_loc() {
+        check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
+        check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
+        check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
+        check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
+        check_location(r"trait A$0 {}", None);
+        check_location(r"trait A { fn f$0 }", None);
+    }
+
+    #[test]
+    fn test_impl_loc() {
+        check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
+        check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
+        check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
+        check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
+        check_location(r"impl A$0 {}", None);
+        check_location(r"impl A { fn f$0 }", None);
+    }
+
+    #[test]
+    fn test_use_loc() {
+        check_location(r"use f$0", ImmediateLocation::Use);
+        check_location(r"use f$0;", ImmediateLocation::Use);
+        check_location(r"use f::{f$0}", None);
+        check_location(r"use {f$0}", None);
+    }
+
+    #[test]
+    fn test_record_field_loc() {
+        check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
+        check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
+        check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
+    }
+
+    #[test]
+    fn test_block_expr_loc() {
+        check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
+        check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
+    }
+
+    #[test]
+    fn test_ident_pat_loc() {
+        check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
+        check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
+        check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
+        check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
+    }
+
+    #[test]
+    fn test_ref_expr_loc() {
+        check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
+    }
+
+    #[test]
+    fn test_item_list_loc() {
+        check_location(r"i$0", ImmediateLocation::ItemList);
+        check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
+        check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
+        check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
+        check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
+        check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
+        check_location(r"mod foo$0 {}", None);
+    }
+
+    #[test]
+    fn test_impl_prev_sibling() {
+        check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
+        check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
+        check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
+        check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
+        check_prev_sibling(r"impl A for w$0 {}", None);
+        check_prev_sibling(r"impl A for w$0", None);
+    }
+
+    #[test]
+    fn test_trait_prev_sibling() {
+        check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
+        check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
+    }
+
+    #[test]
+    fn test_if_expr_prev_sibling() {
+        check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
+        check_prev_sibling(r"fn foo() { if true {}; w$0", None);
+    }
+}


Test patch:
diff --git a/crates/ide_completion/src/test_utils.rs b/crates/ide_completion/src/test_utils.rs
index 6656fd725b..93c7c872cc 100644
--- a/crates/ide_completion/src/test_utils.rs
+++ b/crates/ide_completion/src/test_utils.rs
@@ -12,7 +12,7 @@ use ide_db::{
 use itertools::Itertools;
 use stdx::{format_to, trim_indent};
 use syntax::{AstNode, NodeOrToken, SyntaxElement};
-use test_utils::{assert_eq_text, RangeOrOffset};
+use test_utils::assert_eq_text;
 
 use crate::{item::CompletionKind, CompletionConfig, CompletionItem};
 
@@ -36,10 +36,7 @@ pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
     let mut database = RootDatabase::default();
     database.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let offset = match range_or_offset {
-        RangeOrOffset::Range(_) => panic!(),
-        RangeOrOffset::Offset(it) => it,
-    };
+    let offset = range_or_offset.expect_offset();
     (database, FilePosition { file_id, offset })
 }
 
@@ -52,10 +49,11 @@ pub(crate) fn do_completion_with_config(
     code: &str,
     kind: CompletionKind,
 ) -> Vec<CompletionItem> {
-    let mut kind_completions: Vec<CompletionItem> =
-        get_all_items(config, code).into_iter().filter(|c| c.completion_kind == kind).collect();
-    kind_completions.sort_by(|l, r| l.label().cmp(r.label()));
-    kind_completions
+    get_all_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .sorted_by(|l, r| l.label().cmp(r.label()))
+        .collect()
 }
 
 pub(crate) fn completion_list(code: &str, kind: CompletionKind) -> String {
diff --git a/crates/ide_db/src/call_info/tests.rs b/crates/ide_db/src/call_info/tests.rs
index 1aeda08e5f..b585085f38 100644
--- a/crates/ide_db/src/call_info/tests.rs
+++ b/crates/ide_db/src/call_info/tests.rs
@@ -1,6 +1,5 @@
 use base_db::{fixture::ChangeFixture, FilePosition};
 use expect_test::{expect, Expect};
-use test_utils::RangeOrOffset;
 
 use crate::RootDatabase;
 
@@ -10,10 +9,7 @@ pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
     let mut database = RootDatabase::default();
     database.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let offset = match range_or_offset {
-        RangeOrOffset::Range(_) => panic!(),
-        RangeOrOffset::Offset(it) => it,
-    };
+    let offset = range_or_offset.expect_offset();
     (database, FilePosition { file_id, offset })
 }
 
diff --git a/crates/ide_db/src/traits/tests.rs b/crates/ide_db/src/traits/tests.rs
index 2a5482024d..de994407c7 100644
--- a/crates/ide_db/src/traits/tests.rs
+++ b/crates/ide_db/src/traits/tests.rs
@@ -2,7 +2,6 @@ use base_db::{fixture::ChangeFixture, FilePosition};
 use expect_test::{expect, Expect};
 use hir::Semantics;
 use syntax::ast::{self, AstNode};
-use test_utils::RangeOrOffset;
 
 use crate::RootDatabase;
 
@@ -12,10 +11,7 @@ pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
     let mut database = RootDatabase::default();
     database.apply_change(change_fixture.change);
     let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
-    let offset = match range_or_offset {
-        RangeOrOffset::Range(_) => panic!(),
-        RangeOrOffset::Offset(it) => it,
-    };
+    let offset = range_or_offset.expect_offset();
     (database, FilePosition { file_id, offset })
 }
 
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index fce4fd6bf2..bd017567ca 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -96,6 +96,21 @@ pub enum RangeOrOffset {
     Offset(TextSize),
 }
 
+impl RangeOrOffset {
+    pub fn expect_offset(self) -> TextSize {
+        match self {
+            RangeOrOffset::Offset(it) => it,
+            RangeOrOffset::Range(_) => panic!("expected an offset but got a range instead"),
+        }
+    }
+    pub fn expect_range(self) -> TextRange {
+        match self {
+            RangeOrOffset::Range(it) => it,
+            RangeOrOffset::Offset(_) => panic!("expected a range but got an offset"),
+        }
+    }
+}
+
 impl From<RangeOrOffset> for TextRange {
     fn from(selection: RangeOrOffset) -> Self {
         match selection {