// 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);