JezK
Edit File: array-shift.js
// Copyright 2010 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // Check that shifting array of holes keeps it as array of holes (function() { var array = new Array(10); array.shift(); assertFalse(0 in array); })(); // Now check the case with array of holes and some elements on prototype. (function() { var len = 9; var array = new Array(len); Array.prototype[3] = "@3"; Array.prototype[7] = "@7"; assertEquals(len, array.length); for (var i = 0; i < array.length; i++) { assertEquals(array[i], Array.prototype[i]); } array.shift(); assertEquals(len - 1, array.length); // Note that shift copies values from prototype into the array. assertEquals(array[2], Array.prototype[3]); assertTrue(array.hasOwnProperty(2)); assertEquals(array[6], Array.prototype[7]); assertTrue(array.hasOwnProperty(6)); // ... but keeps the rest as holes: Array.prototype[5] = "@5"; assertEquals(array[5], Array.prototype[5]); assertFalse(array.hasOwnProperty(5)); assertEquals(array[3], Array.prototype[3]); assertFalse(array.hasOwnProperty(3)); assertEquals(array[7], Array.prototype[7]); assertFalse(array.hasOwnProperty(7)); assertTrue(delete Array.prototype[3]); assertTrue(delete Array.prototype[5]); assertTrue(delete Array.prototype[7]); })(); // Now check the case with array of holes and some elements on prototype // which is an array itself. (function() { var len = 9; var array = new Array(len); var array_proto = new Array(); array_proto[3] = "@3"; array_proto[7] = "@7"; array.__proto__ = array_proto; assertEquals(len, array.length); for (var i = 0; i < array.length; i++) { assertEquals(array[i], array_proto[i]); } array.shift(); assertEquals(len - 1, array.length); // Note that shift copies values from prototype into the array. assertEquals(array[2], array_proto[3]); assertTrue(array.hasOwnProperty(2)); assertEquals(array[6], array_proto[7]); assertTrue(array.hasOwnProperty(6)); // ... but keeps the rest as holes: array_proto[5] = "@5"; assertEquals(array[5], array_proto[5]); assertFalse(array.hasOwnProperty(5)); assertEquals(array[3], array_proto[3]); assertFalse(array.hasOwnProperty(3)); assertEquals(array[7], array_proto[7]); assertFalse(array.hasOwnProperty(7)); })();