JSTests/test262/test/built-ins/Object/defineProperties/15.2.3.7-6-a-146.js

// Copyright (c) 2012 Ecma International.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
es5id: 15.2.3.7-6-a-146
description: >
    Object.defineProperties - 'O' is an Array, 'name' is the length
    property of 'O', test TypeError is thrown when the [[Value]] field
    of 'desc' is an Object that both toString and valueOf wouldn't
    return primitive value (15.4.5.1 step 3.c)
---*/

var arr = [];
var toStringAccessed = false;
var valueOfAccessed = false;
assert.throws(TypeError, function() {
  Object.defineProperties(arr, {
    length: {
      value: {
        toString: function() {
          toStringAccessed = true;
          return {};
        },

        valueOf: function() {
          valueOfAccessed = true;
          return {};
        }
      }
    }
  });
});
assert(toStringAccessed, 'toStringAccessed !== true');
assert(valueOfAccessed, 'valueOfAccessed !== true');