v8/test/mjsunit/array-slice.js
2010-03-04 21:29:33 +00:00

174 lines
5.6 KiB
JavaScript

// 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 slicing array of holes keeps it as array of holes
(function() {
var array = new Array(10);
for (var i = 0; i < 7; i++) {
var sliced = array.slice();
assertEquals(array.length, sliced.length);
assertFalse(0 in sliced);
}
})();
// Check various variants of empty array's slicing.
(function() {
for (var i = 0; i < 7; i++) {
assertEquals([], [].slice(0, 0));
assertEquals([], [].slice(1, 0));
assertEquals([], [].slice(0, 1));
assertEquals([], [].slice(-1, 0));
}
})();
// Check various forms of arguments omission.
(function() {
var array = new Array(7);
for (var i = 0; i < 7; i++) {
assertEquals(array, array.slice());
assertEquals(array, array.slice(0));
assertEquals(array, array.slice(undefined));
assertEquals(array, array.slice("foobar"));
assertEquals(array, array.slice(undefined, undefined));
}
})();
// Check variants of negatives and positive indices.
(function() {
var array = new Array(7);
for (var i = 0; i < 7; i++) {
assertEquals(7, array.slice(-100).length);
assertEquals(3, array.slice(-3).length);
assertEquals(3, array.slice(4).length);
assertEquals(1, array.slice(6).length);
assertEquals(0, array.slice(7).length);
assertEquals(0, array.slice(8).length);
assertEquals(0, array.slice(100).length);
assertEquals(0, array.slice(0, -100).length);
assertEquals(4, array.slice(0, -3).length);
assertEquals(4, array.slice(0, 4).length);
assertEquals(6, array.slice(0, 6).length);
assertEquals(7, array.slice(0, 7).length);
assertEquals(7, array.slice(0, 8).length);
assertEquals(7, array.slice(0, 100).length);
// Some exotic cases.
obj = { toString: function() { throw 'Exception'; } };
// More than 2 arguments:
assertEquals(7, array.slice(0, 7, obj, null, undefined).length);
// Custom conversion:
assertEquals(1, array.slice({valueOf: function() { return 1; }},
{toString: function() { return 2; }}).length);
// Throwing an exception in conversion:
try {
assertEquals(7, array.slice(0, obj).length);
throw 'Should have thrown';
} catch (e) {
assertEquals('Exception', e);
}
}
})();
// Nasty: modify the array in ToInteger.
(function() {
var array = [];
var expected = []
bad_guy = { valueOf: function() { array.push(array.length); return -1; } };
for (var i = 0; i < 13; i++) {
var sliced = array.slice(bad_guy);
expected.push(i);
assertEquals(expected, array);
// According to the spec (15.4.4.10), length is calculated before
// performing ToInteger on arguments.
if (i == 0) {
assertEquals([], sliced); // Length was 0, nothing to get.
} else {
// Actually out of array [0..i] we get [i - 1] as length is i.
assertEquals([i - 1], sliced);
}
}
})();
// Now check the case with array of holes and some elements on prototype.
(function() {
var len = 9;
var array = new Array(len);
var at3 = "@3";
var at7 = "@7";
for (var i = 0; i < 7; i++) {
Array.prototype[3] = at3;
Array.prototype[7] = at7;
assertEquals(len, array.length);
for (var i = 0; i < array.length; i++) {
assertEquals(array[i], Array.prototype[i]);
}
var sliced = array.slice();
assertEquals(len, sliced.length);
assertTrue(delete Array.prototype[3]);
assertTrue(delete Array.prototype[7]);
// Note that slice copies values from prototype into the array.
assertEquals(array[3], undefined);
assertFalse(array.hasOwnProperty(3));
assertEquals(sliced[3], at3);
assertTrue(sliced.hasOwnProperty(3));
assertEquals(array[7], undefined);
assertFalse(array.hasOwnProperty(7));
assertEquals(sliced[7], at7);
assertTrue(sliced.hasOwnProperty(7));
// ... but keeps the rest as holes:
Array.prototype[5] = "@5";
assertEquals(array[5], Array.prototype[5]);
assertFalse(array.hasOwnProperty(5));
assertEquals(sliced[5], Array.prototype[5]);
assertFalse(sliced.hasOwnProperty(5));
assertTrue(delete Array.prototype[5]);
}
})();