Source code
Revision control
Copy as Markdown
Other Tools
// 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. For non-configurable properties, step 10.a.i
of [[DefineOwnProperty]] rejects if relaxing the [[Writable]] attribute.
es5id: 15.2.3.6-4-16
description: >
Object.defineProperty throws TypeError when relaxing [[Writable]]
on non-configurable data properties
---*/
var o = {};
// create a data valued property; all other attributes default to false.
var d1 = {
value: 101
};
Object.defineProperty(o, "foo", d1);
// now, relaxing [[Writable]] on "foo" should fail, since both
// [[Configurable]] and [[Writable]] on the original property will be false.
var desc = {
value: 101,
writable: true
};
assert.throws(TypeError, function() {
Object.defineProperty(o, "foo", desc);
});
// the property should remain unchanged.
var d2 = Object.getOwnPropertyDescriptor(o, "foo");
assert.sameValue(d2.value, 101, 'd2.value');
assert.sameValue(d2.writable, false, 'd2.writable');
assert.sameValue(d2.enumerable, false, 'd2.enumerable');
assert.sameValue(d2.configurable, false, 'd2.configurable');
reportCompare(0, 0);