test262/test/built-ins/Object/defineProperty/15.2.3.6-4-16.js

44 lines
1.3 KiB
JavaScript

// 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
includes: [runTestCase.js]
---*/
function testcase() {
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 };
try {
Object.defineProperty(o, "foo", desc);
}
catch (e) {
if (e instanceof TypeError) {
// the property should remain unchanged.
var d2 = Object.getOwnPropertyDescriptor(o, "foo");
if (d2.value === 101 &&
d2.writable === false &&
d2.enumerable === false &&
d2.configurable === false) {
return true;
}
}
}
}
runTestCase(testcase);