36 lines
1.4 KiB
JavaScript
36 lines
1.4 KiB
JavaScript
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// Copyright 2015 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Test the ES2015 @@species feature
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'use strict';
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let TypedArray = Uint8Array.__proto__;
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// The @@species property exists on the right objects and has the right values
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let classesWithSpecies = [RegExp, Array, TypedArray, ArrayBuffer, Map, Set, Promise];
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let classesWithoutSpecies = [Object, Function, String, Number, Symbol, WeakMap, WeakSet];
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for (let constructor of classesWithSpecies) {
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assertEquals(constructor, constructor[Symbol.species]);
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assertThrows(function() { constructor[Symbol.species] = undefined }, TypeError);
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let descriptor = Object.getOwnPropertyDescriptor(constructor, Symbol.species);
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assertTrue(descriptor.configurable);
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assertFalse(descriptor.enumerable);
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assertEquals(undefined, descriptor.writable);
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assertEquals(undefined, descriptor.set);
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assertEquals('function', typeof descriptor.get);
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}
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// @@species is defined with distinct getters
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assertEquals(classesWithSpecies.length,
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new Set(classesWithSpecies.map(constructor =>
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Object.getOwnPropertyDescriptor(
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constructor, Symbol.species).get)
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).size);
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for (let constructor of classesWithoutSpecies)
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assertEquals(undefined, constructor[Symbol.species]);
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