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
|
// Copyright (c) 2012 Ecma International. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
info: |
Step 4 of defineProperty calls the [[DefineOwnProperty]] internal method
of O to define the property. Step 7b of [[DefineOwnProperty]] rejects if
current.[[Enumerable]] and desc.[[Enumerable]] are the boolean negations
of each other.
es5id: 15.2.3.6-4-11
description: >
Object.defineProperty throws TypeError when changing
[[Enumerable]] from true to false on non-configurable accessor
properties
---*/
var o = {};
// create an accessor property; all other attributes default to false.
// dummy getter
var getter = function () { return 1; }
var d1 = { get: getter, enumerable: true, configurable: false };
Object.defineProperty(o, "foo", d1);
// now, setting enumerable to true should fail, since [[Configurable]]
// on the original property will be false.
var desc = { get: getter, enumerable: false };
assert.throws(TypeError, function() {
Object.defineProperty(o, "foo", desc);
});
// the property should remain unchanged.
var d2 = Object.getOwnPropertyDescriptor(o, "foo");
assert.sameValue(d2.get, getter, 'd2.get');
assert.sameValue(d2.enumerable, true, 'd2.enumerable');
assert.sameValue(d2.configurable, false, 'd2.configurable');
|
