length-set-object.js

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/*

 * Any copyright is dedicated to the Public Domain.

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

 * Contributor:

 *   Jeff Walden <jwalden+code@mit.edu>

*/

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

var BUGNUMBER = 657298;

var summary = 'Various quirks of setting array length properties to objects';

print(BUGNUMBER + ": " + summary);

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

 * BEGIN TEST *

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

function invokeConversionTwice1()

  var count = 0;

  [].length = { valueOf: function() { count++; return 1; } };

  assertEq(count, 2);

invokeConversionTwice1();

function invokeConversionTwice2()

  var count = 0;

  [].length = { toString: function() { count++; return 1; }, valueOf: null };

  assertEq(count, 2);

invokeConversionTwice2();

function dontOverwriteError1()

try

    [].length = { valueOf: {}, toString: {} };

    throw new Error("didn't throw a TypeError");

  catch (e)

    assertEq(e instanceof TypeError, true,

             "expected a TypeError running out of conversion options, got " + e);

dontOverwriteError1();

function dontOverwriteError2()

try

    [].length = { valueOf: function() { throw "error"; } };

    throw new Error("didn't throw a TypeError");

  catch (e)

    assertEq(e, "error", "expected 'error' from failed conversion, got " + e);

dontOverwriteError2();

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

if (typeof reportCompare === "function")

  reportCompare(true, true);

print("All tests passed!");