Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 28 | // Flags: --legacy-const |
| 29 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 30 | // const variables should be read-only |
| 31 | const c = 42; |
| 32 | c = 87; |
| 33 | assertEquals(42, c); |
| 34 | |
| 35 | |
| 36 | // const variables are not behaving like other JS variables when it comes |
| 37 | // to scoping - in fact they behave more sanely. Inside a 'with' they do |
| 38 | // not interfere with the 'with' scopes. |
| 39 | |
| 40 | (function () { |
| 41 | with ({ x: 42 }) { |
| 42 | const x = 7; |
| 43 | } |
| 44 | x = 5; |
| 45 | assertEquals(7, x); |
| 46 | })(); |
| 47 | |
| 48 | |
| 49 | // const variables may be declared but never initialized, in which case |
| 50 | // their value is undefined. |
| 51 | |
| 52 | (function (sel) { |
| 53 | if (sel == 0) |
| 54 | with ({ x: 42 }) { |
| 55 | const x; |
| 56 | } |
| 57 | else |
| 58 | x = 3; |
| 59 | x = 5; |
| 60 | assertTrue(typeof x == 'undefined'); |
| 61 | })(1); |
| 62 | |
| 63 | |
| 64 | // const variables may be initialized to undefined. |
| 65 | (function () { |
| 66 | with ({ x: 42 }) { |
| 67 | const x = undefined; |
| 68 | } |
| 69 | x = 5; |
| 70 | assertTrue(typeof x == 'undefined'); |
| 71 | })(); |
| 72 | |
| 73 | |
| 74 | // const variables may be accessed in inner scopes like any other variable. |
| 75 | (function () { |
| 76 | function bar() { |
| 77 | assertEquals(7, x); |
| 78 | } |
| 79 | with ({ x: 42 }) { |
| 80 | const x = 7; |
| 81 | } |
| 82 | x = 5 |
| 83 | bar(); |
| 84 | })(); |
| 85 | |
| 86 | |
| 87 | // const variables may be declared via 'eval' |
| 88 | (function () { |
| 89 | with ({ x: 42 }) { |
| 90 | eval('const x = 7'); |
| 91 | } |
| 92 | x = 5; |
| 93 | assertEquals(7, x); |
| 94 | })(); |