text: /// Copyright (c) 2009 Microsoft Corporation 
  /// 
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  /// that the following conditions are met: 
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  ///      the following disclaimer. 
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  ///      the following disclaimer in the documentation and/or other materials provided with the distribution.  
  ///    * Neither the name of Microsoft nor the names of its contributors may be used to
  ///      endorse or promote products derived from this software without specific prior written permission.
  /// 
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  /// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  /// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
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  /// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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  /*
  Step 4 of defineProperty calls the [[DefineOwnProperty]] internal method
  of O to define the property. For non-configurable properties, step 11.a.i
  of [[DefineOwnProperty]] rejects changing the setter if present.
  */
  
  ES5Harness.registerTest( {
  id: "15.2.3.6-4-18",
  
  path: "TestCases/chapter15/15.2/15.2.3/15.2.3.6/15.2.3.6-4-18.js",
  
  description: "Object.defineProperty throws TypeError when changing setter of non-configurable accessor properties",
  
  test: function testcase() {
    var o = {};
  
    // create an accessor property; all other attributes default to false.
    // dummy getter
    var getter = function () { return 1;}
    var d1 = { get: getter };
    Object.defineProperty(o, "foo", d1);
  
    // now, trying to change the setter should fail, since [[Configurable]]
    // on the original property will be false.
    var setter = function (x) {};
    var desc = { set: setter };
  
    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.get === getter &&
  	      d2.configurable === false &&
            d2.enumerable === false) {
          return true;
        }
      }
    }
   },
  
  precondition: function prereq() {
    return fnExists(Object.defineProperty) && fnExists(Object.getOwnPropertyDescriptor);
   }
  });
  