goto where trait method impl

crates/ide/src/goto_definition.rs

@@ -1,7 +1,7 @@
 use std::convert::TryInto;
 
 use crate::{doc_links::token_as_doc_comment, FilePosition, NavigationTarget, RangeInfo, TryToNav};
-use hir::{AsAssocItem, Semantics};
+use hir::{AsAssocItem, AssocItem, Semantics};
 use ide_db::{
     base_db::{AnchoredPath, FileId, FileLoader},
     defs::{Definition, IdentClass},
@@ -65,7 +65,7 @@ pub(crate) fn goto_definition(
                     .definitions()
                     .into_iter()
                     .flat_map(|def| {
-                        try_find_trait_item_definition(sema.db, &def)
+                        try_filter_trait_item_definition(sema, &def, &token)
                             .unwrap_or_else(|| def_to_nav(sema.db, def))
                     })
                     .collect(),
@@ -104,32 +104,38 @@ fn try_lookup_include_path(
         docs: None,
     })
 }
-
-/// finds the trait definition of an impl'd item
+/// finds the trait definition of an impl'd item, except function
 /// e.g.
 /// ```rust
-/// trait A { fn a(); }
+/// trait A { type a; }
 /// struct S;
-/// impl A for S { fn a(); } // <-- on this function, will get the location of a() in the trait
+/// impl A for S { type a = i32; } // <-- on this associate type, will get the location of a in the trait
 /// ```
-fn try_find_trait_item_definition(
-    db: &RootDatabase,
+fn try_filter_trait_item_definition(
+    sema: &Semantics<RootDatabase>,
     def: &Definition,
+    token: &SyntaxToken,
 ) -> Option<Vec<NavigationTarget>> {
-    let name = def.name(db)?;
+    let db = sema.db;
     let assoc = def.as_assoc_item(db)?;
-
-    let imp = match assoc.container(db) {
-        hir::AssocItemContainer::Impl(imp) => imp,
-        _ => return None,
-    };
-
-    let trait_ = imp.trait_(db)?;
-    trait_
-        .items(db)
-        .iter()
-        .find_map(|itm| (itm.name(db)? == name).then(|| itm.try_to_nav(db)).flatten())
-        .map(|it| vec![it])
+    match assoc {
+        AssocItem::Function(..) => {
+            IdentClass::classify_token_to_impl(sema, &token).map(|def| def_to_nav(db, def))
+        }
+        AssocItem::Const(..) | AssocItem::TypeAlias(..) => {
+            let imp = match assoc.container(db) {
+                hir::AssocItemContainer::Impl(imp) => imp,
+                _ => return None,
+            };
+            let trait_ = imp.trait_(db)?;
+            let name = def.name(db)?;
+            trait_
+                .items(db)
+                .iter()
+                .find_map(|itm| (itm.name(db)? == name).then(|| itm.try_to_nav(db)).flatten())
+                .map(|it| vec![it])
+        }
+    }
 }
 
 fn def_to_nav(db: &RootDatabase, def: Definition) -> Vec<NavigationTarget> {
@@ -1331,23 +1337,98 @@ fn main() {
 "#,
         );
     }
-
-    #[test]
-    fn goto_def_of_trait_impl_fn() {
-        check(
-            r#"
+    #[cfg(test)]
+    mod goto_impl_of_trait_fn {
+        use super::check;
+        #[test]
+        fn cursor_on_impl() {
+            check(
+                r#"
 trait Twait {
     fn a();
-    // ^
 }
 
 struct Stwuct;
 
 impl Twait for Stwuct {
     fn a$0();
+     //^
 }
-"#,
-        );
+        "#,
+            );
+        }
+        #[test]
+        fn method_call() {
+            check(
+                r#"
+trait Twait {
+    fn a(&self);
+}
+
+struct Stwuct;
+
+impl Twait for Stwuct {
+    fn a(&self){};
+     //^
+}
+fn f() {
+    let s = Stwuct;
+    s.a$0();
+}
+        "#,
+            );
+        }
+        #[test]
+        fn path_call() {
+            check(
+                r#"
+trait Twait {
+    fn a(&self);
+}
+
+struct Stwuct;
+
+impl Twait for Stwuct {
+    fn a(&self){};
+     //^
+}
+fn f() {
+    let s = Stwuct;
+    Stwuct::a$0(&s);
+}
+        "#,
+            );
+        }
+        #[test]
+        fn where_clause_can_work() {
+            check(
+                r#"
+trait G {
+    fn g(&self);
+}
+trait Bound{}
+trait EA{}
+struct Gen<T>(T);
+impl <T:EA> G for Gen<T> {
+    fn g(&self) {
+    }
+}
+impl <T> G for Gen<T>
+where T : Bound
+{
+    fn g(&self){
+     //^
+    }
+}
+struct A;
+impl Bound for A{}
+fn f() {
+    let gen = Gen::<A>(A);
+    gen.g$0();
+}
+                "#,
+            );
+        }
     }
 
     #[test]