Fixed handling of heritage clauses in extension names

Author: derekxu16

lib/declaration.ts

@@ -842,14 +842,8 @@ export default class DeclarationTranspiler extends base.TranspilerBase {
       keyword: string, decl: base.ClassLike|ts.TypeLiteralNode, name: ts.Identifier,
       typeParameters: ts.NodeArray<ts.TypeParameterDeclaration>,
       heritageClauses: ts.NodeArray<ts.HeritageClause>) {
-    const visitName = () => {
-      this.visitClassLikeName(name, typeParameters, heritageClauses, false);
-    };
-    const visitNameOfExtensions = () => {
-      this.visitClassLikeName(name, typeParameters, heritageClauses, true);
-    };
     this.emit(keyword);
-    visitName();
+    this.visitClassLikeName(name, typeParameters, heritageClauses, false);
     this.emit('{');
 
     this.maybeEmitFakeConstructors(decl);
@@ -872,6 +866,12 @@ export default class DeclarationTranspiler extends base.TranspilerBase {
     this.visitClassBody(decl, name);
     this.emit('}\n');
     if (this.promiseMethods.size) {
+      const visitName = () => {
+        this.visitClassLikeName(name, typeParameters, ts.createNodeArray(), false);
+      };
+      const visitNameOfExtensions = () => {
+        this.visitClassLikeName(name, typeParameters, ts.createNodeArray(), true);
+      };
       this.emitMethodsAsExtensions(name, visitName, visitNameOfExtensions, this.promiseMethods);
       this.promiseMethods.clear();
     }

test/declaration_test.ts

@@ -302,6 +302,41 @@ extension XExtensions<T> on X<T> {
   }
 }
 
+@JS()
+abstract class Promise<T> {}`);
+      expectTranslate(`declare interface Y {
+        a: number;
+      }
+      
+      declare interface Z extends Y {
+        f(): Promise<string>;
+      }`).to.equal(`import "package:js/js_util.dart" show promiseToFuture;
+
+@anonymous
+@JS()
+abstract class Y {
+  external num get a;
+  external set a(num v);
+  external factory Y({num a});
+}
+
+@anonymous
+@JS()
+abstract class Z implements Y {}
+
+@JS('Z')
+abstract class _Z {
+  Promise<String> f();
+}
+
+extension ZExtensions on Z {
+  Future<String> f() {
+    final Object t = this;
+    final _Z tt = t;
+    return promiseToFuture(tt.f());
+  }
+}
+
 @JS()
 abstract class Promise<T> {}`);
     });