| // 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); |
| |
| // However, subarray instantiates members of the parent class |
| assertEquals(Uint8Array, myTypedArray.subarray(1).constructor); |