JezK
Edit File: const.js
// Copyright 2008 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. // Test const properties and pre/postfix operation. function f() { const x = 1; x++; assertEquals(1, x); x--; assertEquals(1, x); ++x; assertEquals(1, x); --x; assertEquals(1, x); assertEquals(1, x++); assertEquals(1, x--); assertEquals(2, ++x); assertEquals(0, --x); } f(); // Test that the value is read eventhough assignment is disallowed. // Spidermonkey does not do this, but it seems like the right thing to // do so that 'o++' is equivalent to 'o = o + 1'. var valueOfCount = 0; function g() { const o = { valueOf: function() { valueOfCount++; return 42; } }; assertEquals(42, +o); assertEquals(1, valueOfCount); o++; assertEquals(42, +o); assertEquals(3, valueOfCount); ++o; assertEquals(42, +o); assertEquals(5, valueOfCount); o--; assertEquals(42, +o); assertEquals(7, valueOfCount); --o; assertEquals(42, +o); assertEquals(9, valueOfCount); } g();