test262/test/language/expressions/delete/11.4.1-4.a-5.js

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

/*---
info: >
    This test is actually testing the [[Delete]] internal method (8.12.8). Since the
    language provides no way to directly exercise [[Delete]], the tests are placed here.
es5id: 11.4.1-4.a-5
description: >
    delete operator returns false when deleting the declaration of the environment object
    inside 'with'
flags: [noStrict]
---*/

function testcase() {
  var o = new Object();
  o.x = 1;
  var d;
  with(o)
  {
    d = delete o;
  }

  assert.sameValue(d, false, 'd');
  assert.sameValue(typeof(o), 'object', 'typeof(o)');
  assert.sameValue(o.x, 1, 'o.x');
 }
testcase();