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. 29 function 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 45 f(); 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'. 50 var valueOfCount = 0; 51 52 function 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 70 g(); 71
