global-numeric-properties.js

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/*

 * Any copyright is dedicated to the Public Domain.

 * http://creativecommons.org/licenses/publicdomain/

*/

//-----------------------------------------------------------------------------

var BUGNUMBER = 537863;

var summary =

  'undefined, Infinity, and NaN global properties should not be writable';

print(BUGNUMBER + ": " + summary);

/**************

 * BEGIN TEST *

 **************/

var desc, old, error;

var global = this;

var names = ["NaN", "Infinity", "undefined"];

for (var i = 0; i < names.length; i++)

  var name = names[i];

  desc = Object.getOwnPropertyDescriptor(global, name);

  assertEq(desc !== undefined, true, name + " should be present");

  assertEq(desc.enumerable, false, name + " should not be enumerable");

  assertEq(desc.configurable, false, name + " should not be configurable");

  assertEq(desc.writable, false, name + " should not be writable");

  old = global[name];

  global[name] = 17;

  assertEq(global[name], old, name + " changed on setting?");

  error = "before";

try

    throw new TypeError("SpiderMonkey doesn't currently implement " +

                        "strict-mode throwing when setting a readonly " +

                        "property, not running this bit of test for now; " +

                        "see bug 537873");

    (function() { "use strict"; global[name] = 42; error = "didn't throw"; })();

  catch (e)

    if (e instanceof TypeError)

      error = "typeerror";

    else

      error = "bad exception: " + e;

  assertEq(error, "typeerror", "wrong strict mode error setting " + name);

/******************************************************************************/

reportCompare(true, true);

print("All tests passed!");