test/built-ins/Object/defineProperty/15.2.3.6-4-13.js


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// 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 9a of
    [[DefineOwnProperty]] rejects changing the kind of a property.
es5id: 15.2.3.6-4-13
description: >
    Object.defineProperty throws TypeError when changing
    non-configurable accessor properties to data properties
---*/

  var o = {};

  // create an accessor property; all other attributes default to false.
 
  // dummy getter
  var getter = function () { return 1; }
  var d1 = { get: getter, configurable: false };
  Object.defineProperty(o, "foo", d1);

  // changing "foo" to be a data property should fail, since [[Configurable]]
  // on the original property will be false.
  var desc = { value: 101 };
assert.throws(TypeError, function() {
    Object.defineProperty(o, "foo", desc);
});
      // the property should remain an accessor property.
      var d2 = Object.getOwnPropertyDescriptor(o, "foo");
assert.sameValue(d2.get, getter, 'd2.get');
assert.sameValue(d2.configurable, false, 'd2.configurable');