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); 39
