mirror of https://github.com/tc39/test262.git
29 lines
836 B
JavaScript
29 lines
836 B
JavaScript
// Copyright (C) 2016 the V8 project authors. All rights reserved.
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// This code is governed by the BSD license found in the LICENSE file.
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/*---
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es6id: 23.4.1
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description: Subclassing the WeakSet object
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info: |
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23.4.1 The WeakSet Constructor
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...
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The WeakSet constructor is designed to be subclassable. It may be used as the
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value in an extends clause of a class definition. Subclass constructors that
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intend to inherit the specified WeakSet behaviour must include a super call to
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the WeakSet constructor to create and initialize the subclass instance with
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the internal state necessary to support the WeakSet.prototype built-in
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methods.
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features: [WeakSet]
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---*/
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class WS extends WeakSet {}
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var set = new WS();
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var obj = {};
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assert.sameValue(set.has(obj), false);
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set.add(obj);
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assert.sameValue(set.has(obj), true);
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