JSTests/test262/test/language/expressions/delete/11.4.1-4.a-4.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-4
description: >
    delete operator returns false when deleting a non-configurable
    data property (NaN)
flags: [noStrict]
---*/

  // NaN (15.1.1.1) has [[Configurable]] set to false.
  var d = delete NaN;

assert.sameValue(d, false, 'd');