JSTests/test262/test/built-ins/Array/prototype/map/15.4.4.19-8-b-1.js

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

/*---
esid: sec-array.prototype.map
es5id: 15.4.4.19-8-b-1
description: >
    Array.prototype.map - callbackfn not called for indexes never been
    assigned values
---*/

  var callCnt = 0;
  function callbackfn(val, idx, obj)
  {
    callCnt++;
    return 1;
  }

  var srcArr = new Array(10);
  srcArr[1] = undefined; //explicitly assigning a value
  var resArr = srcArr.map(callbackfn);

assert.sameValue(resArr.length, 10, 'resArr.length');
assert.sameValue(callCnt, 1, 'callCnt');