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// Flags: --legacy-const 29 30// Test const properties and pre/postfix operation. 31function f() { 32 const x = 1; 33 x++; 34 assertEquals(1, x); 35 x--; 36 assertEquals(1, x); 37 ++x; 38 assertEquals(1, x); 39 --x; 40 assertEquals(1, x); 41 assertEquals(1, x++); 42 assertEquals(1, x--); 43 assertEquals(2, ++x); 44 assertEquals(0, --x); 45} 46 47f(); 48 49// Test that the value is read eventhough assignment is disallowed. 50// Spidermonkey does not do this, but it seems like the right thing to 51// do so that 'o++' is equivalent to 'o = o + 1'. 52var valueOfCount = 0; 53 54function g() { 55 const o = { valueOf: function() { valueOfCount++; return 42; } }; 56 assertEquals(42, +o); 57 assertEquals(1, valueOfCount); 58 o++; 59 assertEquals(42, +o); 60 assertEquals(3, valueOfCount); 61 ++o; 62 assertEquals(42, +o); 63 assertEquals(5, valueOfCount); 64 o--; 65 assertEquals(42, +o); 66 assertEquals(7, valueOfCount); 67 --o; 68 assertEquals(42, +o); 69 assertEquals(9, valueOfCount); 70} 71 72g(); 73