| // Copyright (C) 2019 Leo Balter. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| |
| /*--- |
| esid: sec-weak-ref.prototype.deref |
| description: Throws a TypeError if this does not have a [[Target]] internal slot |
| info: | |
| WeakRef.prototype.deref () |
| |
| 1. Let weakRef be the this value. |
| 2. If Type(weakRef) is not Object, throw a TypeError exception. |
| 3. If weakRef does not have a [[Target]] internal slot, throw a TypeError exception. |
| 4. Let target be the value of weakRef.[[Target]]. |
| 5. If target is not empty, |
| a. Perform ! KeepDuringJob(target). |
| b. Return target. |
| 6. Return undefined. |
| features: [WeakRef, FinalizationGroup] |
| ---*/ |
| |
| assert.sameValue(typeof WeakRef.prototype.deref, 'function'); |
| |
| var deref = WeakRef.prototype.deref; |
| |
| assert.throws(TypeError, function() { |
| deref.call({ ['[[Target]]']: {} }); |
| }, 'Ordinary object without [[Target]]'); |
| |
| assert.throws(TypeError, function() { |
| deref.call(WeakRef.prototype); |
| }, 'WeakRef.prototype does not have a [[Target]] internal slot'); |
| |
| assert.throws(TypeError, function() { |
| deref.call(WeakRef); |
| }, 'WeakRef does not have a [[Target]] internal slot'); |
| |
| var fg = new FinalizationGroup(function() {}); |
| assert.throws(TypeError, function() { |
| deref.call(fg); |
| }, 'FinalizationGroup instance'); |
| |
| var wm = new WeakMap(); |
| assert.throws(TypeError, function() { |
| deref.call(wm); |
| }, 'WeakMap instance'); |
| |
| var ws = new WeakSet(); |
| assert.throws(TypeError, function() { |
| deref.call(ws); |
| }, 'WeakSet instance'); |