1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
// 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]);
|
