v8/test/mjsunit/harmony/species.js
littledan fb5cbc2e2d Add a --harmony-species flag, defining @@species on constructors
This patch adds the basis for subclassing TypedArrays, Arrays and
ArrayBuffers through the @@species hook, added in ES2015. This is
the first patch in a series. This patch simply defines the
@@species Symbol and installs it on the appropriate constructors.
The behavior is guarded behind the --harmony-species flag.

R=cbruni
BUG=v8:4093
LOG=Y
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
TBR=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1558543002

Cr-Commit-Position: refs/heads/master@{#33095}
2016-01-04 19:39:59 +00:00

38 lines
1.4 KiB
JavaScript

// 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: --harmony-species
// Test the ES2015 @@species feature
'use strict';
let TypedArray = Uint8Array.__proto__;
// The @@species property exists on the right objects and has the right values
let classesWithSpecies = [RegExp, Array, TypedArray, ArrayBuffer, Map, Set, Promise];
let classesWithoutSpecies = [Object, Function, String, Number, Symbol, WeakMap, WeakSet];
for (let constructor of classesWithSpecies) {
assertEquals(constructor, constructor[Symbol.species]);
assertThrows(function() { constructor[Symbol.species] = undefined }, TypeError);
let descriptor = Object.getOwnPropertyDescriptor(constructor, Symbol.species);
assertTrue(descriptor.configurable);
assertFalse(descriptor.enumerable);
assertEquals(undefined, descriptor.writable);
assertEquals(undefined, descriptor.set);
assertEquals('function', typeof descriptor.get);
}
// @@species is defined with distinct getters
assertEquals(classesWithSpecies.length,
new Set(classesWithSpecies.map(constructor =>
Object.getOwnPropertyDescriptor(
constructor, Symbol.species).get)
).size);
for (let constructor of classesWithoutSpecies)
assertEquals(undefined, constructor[Symbol.species]);