1// Copyright 2008 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28// Test const properties and pre/postfix operation. 29function f() { 30 const x = 1; 31 x++; 32 assertEquals(1, x); 33 x--; 34 assertEquals(1, x); 35 ++x; 36 assertEquals(1, x); 37 --x; 38 assertEquals(1, x); 39 assertEquals(1, x++); 40 assertEquals(1, x--); 41 assertEquals(2, ++x); 42 assertEquals(0, --x); 43} 44 45f(); 46 47// Test that the value is read eventhough assignment is disallowed. 48// Spidermonkey does not do this, but it seems like the right thing to 49// do so that 'o++' is equivalent to 'o = o + 1'. 50var valueOfCount = 0; 51 52function g() { 53 const o = { valueOf: function() { valueOfCount++; return 42; } }; 54 assertEquals(42, +o); 55 assertEquals(1, valueOfCount); 56 o++; 57 assertEquals(42, +o); 58 assertEquals(3, valueOfCount); 59 ++o; 60 assertEquals(42, +o); 61 assertEquals(5, valueOfCount); 62 o--; 63 assertEquals(42, +o); 64 assertEquals(7, valueOfCount); 65 --o; 66 assertEquals(42, +o); 67 assertEquals(9, valueOfCount); 68} 69 70g(); 71