| Index: test/mjsunit/es6/legacy-subclassing.js | 
| diff --git a/test/mjsunit/es6/legacy-subclassing.js b/test/mjsunit/es6/legacy-subclassing.js | 
| new file mode 100644 | 
| index 0000000000000000000000000000000000000000..73b684f99461237f55446e4340a61063effd6b71 | 
| --- /dev/null | 
| +++ b/test/mjsunit/es6/legacy-subclassing.js | 
| @@ -0,0 +1,35 @@ | 
| +// Copyright 2015 the V8 project authors. All rights reserved. | 
| +// Use of this source code is governed by a BSD-style license that can be | 
| +// found in the LICENSE file. | 
| + | 
| +// Flags: --noharmony-species | 
| + | 
| +// Before Symbol.species was added, ArrayBuffer subclasses constructed | 
| +// ArrayBuffers, and Array subclasses constructed Arrays, but TypedArray and | 
| +// Promise subclasses constructed an instance of the subclass. | 
| + | 
| +'use strict'; | 
| + | 
| +assertEquals(undefined, Symbol.species); | 
| + | 
| +class MyArray extends Array { } | 
| +let myArray = new MyArray(); | 
| +assertEquals(MyArray, myArray.constructor); | 
| +assertEquals(Array, myArray.map(x => x + 1).constructor); | 
| +assertEquals(Array, myArray.concat().constructor); | 
| + | 
| +class MyUint8Array extends Uint8Array { } | 
| +Object.defineProperty(MyUint8Array.prototype, "BYTES_PER_ELEMENT", {value: 1}); | 
| +let myTypedArray = new MyUint8Array(3); | 
| +assertEquals(MyUint8Array, myTypedArray.constructor); | 
| +assertEquals(MyUint8Array, myTypedArray.map(x => x + 1).constructor); | 
| + | 
| +class MyArrayBuffer extends ArrayBuffer { } | 
| +let myBuffer = new MyArrayBuffer(0); | 
| +assertEquals(MyArrayBuffer, myBuffer.constructor); | 
| +assertEquals(ArrayBuffer, myBuffer.slice().constructor); | 
| + | 
| +class MyPromise extends Promise { } | 
| +let myPromise = new MyPromise(() => {}); | 
| +assertEquals(MyPromise, myPromise.constructor); | 
| +assertEquals(MyPromise, myPromise.then().constructor); | 
|  |