TypeScript extends should not replace parent scope variables

src/NativeScript/ObjC/Inheritance/ObjCTypeScriptExtend.mm

@@ -80,10 +80,13 @@ EncodedJSValue ObjCTypeScriptExtendFunction(ExecState* execState) {
 
     JSScope* scope = callFrame->scope(callFrame->codeBlock()->scopeRegister().offset());
     Identifier constructorName = Identifier::fromString(execState, name);
-    JSValue value = JSScope::resolve(execState, scope, constructorName);
-    if (value.isObject()) {
-        PutPropertySlot slot(value);
-        value.put(execState, constructorName, derivedConstructor, slot);
+    JSValue containingScope = JSScope::resolve(execState, scope, constructorName);
+    if (containingScope.isObject()) {
+        JSValue currentValue = containingScope.get(execState, constructorName);
+        if (currentValue.isCell() && currentValue.asCell() == typeScriptConstructor) {
+            PutPropertySlot slot(containingScope);
+            containingScope.put(execState, constructorName, derivedConstructor, slot);
+        }
     }
 
     // imp_implementationWithBlock calls block copy, class copy and initialize gets skipped

tests/TestRunner/app/Inheritance/TypeScriptTests.js

@@ -1,10 +1,4 @@
 // TODO: Use TypeScript definitions when they get ready
-var __extends = (this && this.__extends) || function (d, b) {
-    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
-    function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
-};
 var TSObject = (function (_super) {
     __extends(TSObject, _super);
     function TSObject() {
@@ -108,18 +102,6 @@ var TSObject1 = (function (_super) {
     TSObject1.ObjCProtocols = [TNSBaseProtocol2];
     return TSObject1;
 })(NSObject);
-var A = (function () {
-    function A() {
-    }
-    return A;
-})();
-var B = (function (_super) {
-    __extends(B, _super);
-    function B() {
-        _super.apply(this, arguments);
-    }
-    return B;
-})(A);
 var UnusedConstructor = (function (_super) {
     __extends(UnusedConstructor, _super);
     function UnusedConstructor() {
@@ -213,6 +195,31 @@ describe(module.id, function () {
             'baseProtocolProperty1Optional called');
     });
     it('PlainExtends', function () {
+        var A = (function () {
+            function A() {
+            }
+            return A;
+        })();
+        var B = (function (_super) {
+            __extends(B, _super);
+            function B() {
+                _super.apply(this, arguments);
+            }
+            return B;
+        })(A);
         expect(new B() instanceof A).toBe(true);
     });
+    it('Scope', function () {
+        global["Derived"] = 3;
+        var Derived = (function (_super) {
+            __extends(Derived, _super);
+            function Derived() {
+                _super.apply(this, arguments);
+            }
+            return Derived;
+        })(NSObject);
+        ;
+        expect(global["Derived"]).toBe(3);
+        delete global["Derived"];
+    });
 });

tests/TestRunner/app/Inheritance/TypeScriptTests.ts

@@ -151,12 +151,6 @@ class TSObject1 extends NSObject {
     public static ObjCProtocols = [TNSBaseProtocol2];
 }
 
-class A {
-}
-
-class B extends A {
-}
-
 class UnusedConstructor extends NSObject {
     private x = 3;
 }
@@ -286,6 +280,19 @@ describe(module.id, function () {
     });
 
     it('PlainExtends', function () {
+        class A {
+        }
+
+        class B extends A {
+        }
+
         expect(new B() instanceof A).toBe(true);
     });
+
+    it('Scope', function () {
+        global["Derived"] = 3;
+        class Derived extends NSObject { };
+        expect(global["Derived"]).toBe(3);
+        delete global["Derived"];
+    });
 });