Narrow variable search scopes if contained in TraitItemFunction (#196)

Author: mkaput

src/lang/defs.rs

@@ -150,12 +150,20 @@ impl SymbolDef {
     pub fn search_scope(&self, db: &AnalysisDatabase) -> SearchScope {
         match &self {
             Self::Variable(var) => {
-                match db.first_ancestor_of_kind(var.syntax_node(db), SyntaxKind::FunctionWithBody) {
-                    Some(owning_function) => SearchScope::file_span(
+                if let Some(owning_function) =
+                    iter::successors(Some(var.syntax_node(db)), SyntaxNode::parent).find(|node| {
+                        matches!(
+                            node.kind(db.upcast()),
+                            SyntaxKind::FunctionWithBody | SyntaxKind::TraitItemFunction
+                        )
+                    })
+                {
+                    SearchScope::file_span(
                         owning_function.stable_ptr().file_id(db.upcast()),
                         owning_function.span(db.upcast()),
-                    ),
-                    None => SearchScope::file(var.definition_stable_ptr.file_id(db.upcast())),
+                    )
+                } else {
+                    SearchScope::file(var.definition_stable_ptr.file_id(db.upcast()))
                 }
             }
 

tests/e2e/find_references/vars.rs

@@ -166,3 +166,28 @@ fn param_captured_by_closure() {
     }
     ")
 }
+
+#[test]
+fn var_in_trait_function_default_body() {
+    test_transform!(find_references, r#"
+    trait Foo<T> {
+        fn foo() {
+            let foobar = 42;
+            let x = foo<caret>bar + 1;
+        }
+    }
+    fn bar() {
+        let foobar = 42;
+    }
+    "#, @r"
+    trait Foo<T> {
+        fn foo() {
+            let <sel=declaration>foobar</sel> = 42;
+            let x = <sel>foobar</sel> + 1;
+        }
+    }
+    fn bar() {
+        let foobar = 42;
+    }
+    ")
+}