Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Flags: --noharmony-species |
| 6 | |
| 7 | // Before Symbol.species was added, ArrayBuffer subclasses constructed |
| 8 | // ArrayBuffers, and Array subclasses constructed Arrays, but TypedArray and |
| 9 | // Promise subclasses constructed an instance of the subclass. |
| 10 | |
| 11 | 'use strict'; |
| 12 | |
| 13 | assertEquals(undefined, Symbol.species); |
| 14 | |
| 15 | class MyArray extends Array { } |
| 16 | let myArray = new MyArray(); |
| 17 | assertEquals(MyArray, myArray.constructor); |
| 18 | assertEquals(Array, myArray.map(x => x + 1).constructor); |
| 19 | assertEquals(Array, myArray.concat().constructor); |
| 20 | |
| 21 | class MyUint8Array extends Uint8Array { } |
| 22 | Object.defineProperty(MyUint8Array.prototype, "BYTES_PER_ELEMENT", {value: 1}); |
| 23 | let myTypedArray = new MyUint8Array(3); |
| 24 | assertEquals(MyUint8Array, myTypedArray.constructor); |
| 25 | assertEquals(MyUint8Array, myTypedArray.map(x => x + 1).constructor); |
| 26 | |
| 27 | class MyArrayBuffer extends ArrayBuffer { } |
| 28 | let myBuffer = new MyArrayBuffer(0); |
| 29 | assertEquals(MyArrayBuffer, myBuffer.constructor); |
| 30 | assertEquals(ArrayBuffer, myBuffer.slice().constructor); |
| 31 | |
| 32 | class MyPromise extends Promise { } |
| 33 | let myPromise = new MyPromise(() => {}); |
| 34 | assertEquals(MyPromise, myPromise.constructor); |
| 35 | assertEquals(MyPromise, myPromise.then().constructor); |
| 36 | |
| 37 | // However, subarray instantiates members of the parent class |
| 38 | assertEquals(Uint8Array, myTypedArray.subarray(1).constructor); |