add completions to show only traits in trait impl statement

Author: dfireBird

crates/ide-completion/src/completions/type.rs

@@ -184,6 +184,16 @@ pub(crate) fn complete_type_path(
                         }
                     }
                 }
+                TypeLocation::ImplTrait => {
+                    acc.add_nameref_keywords_with_colon(ctx);
+                    ctx.process_all_names(&mut |name, def, doc_aliases| {
+                        let is_trait = matches!(def, ScopeDef::ModuleDef(hir::ModuleDef::Trait(_)));
+                        if is_trait {
+                            acc.add_path_resolution(ctx, path_ctx, name, def, doc_aliases);
+                        }
+                    });
+                    return;
+                }
                 _ => {}
             };
 

crates/ide-completion/src/tests/type_pos.rs

@@ -989,3 +989,21 @@ fn foo<'a>() { S::<'static, F$0, _, _>; }
         "#]],
     );
 }
+
+#[test]
+fn complete_traits_on_impl_trait_block() {
+    check(
+        r#"
+trait Foo {}
+
+struct Bar;
+
+impl $0 for Bar { }"#,
+        expect![[r#"
+            tt Foo
+            tt Trait
+            kw crate::
+            kw self::
+        "#]],
+    );
+}