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