JSTests/test262/test/built-ins/Object/defineProperty/15.2.3.6-4-7.js

// 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 7a of [[DefineOwnProperty]] rejects if
    current.[[Configurable]] is false and desc.[[Configurable]] is true.
es5id: 15.2.3.6-4-7
description: >
    Object.defineProperty throws TypeError when changing
    [[Configurable]] from false to true
---*/

  var o = {};

  // create a data valued property; all other attributes default to false.
  var d1 = { value: 101, configurable: false };
  Object.defineProperty(o, "foo", d1);

  var desc = { value: 101, configurable: 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.configurable, false, 'd2.configurable');