Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2014 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Flags: --harmony-arrow-functions |
| 6 | |
| 7 | // Arrow functions are like functions, except they throw when using the |
| 8 | // "new" operator on them. |
| 9 | assertEquals("function", typeof (() => {})); |
| 10 | assertEquals(Function.prototype, Object.getPrototypeOf(() => {})); |
| 11 | assertThrows(function() { new (() => {}); }, TypeError); |
| 12 | assertFalse("prototype" in (() => {})); |
| 13 | |
| 14 | // Check the different syntax variations |
| 15 | assertEquals(1, (() => 1)()); |
| 16 | assertEquals(2, (a => a + 1)(1)); |
| 17 | assertEquals(3, (() => { return 3; })()); |
| 18 | assertEquals(4, (a => { return a + 3; })(1)); |
| 19 | assertEquals(5, ((a, b) => a + b)(1, 4)); |
| 20 | assertEquals(6, ((a, b) => { return a + b; })(1, 5)); |
| 21 | |
| 22 | // The following are tests from: |
| 23 | // http://wiki.ecmascript.org/doku.php?id=harmony:arrow_function_syntax |
| 24 | |
| 25 | // Empty arrow function returns undefined |
| 26 | var empty = () => {}; |
| 27 | assertEquals(undefined, empty()); |
| 28 | |
| 29 | // Single parameter case needs no parentheses around parameter list |
| 30 | var identity = x => x; |
| 31 | assertEquals(empty, identity(empty)); |
| 32 | |
| 33 | // No need for parentheses even for lower-precedence expression body |
| 34 | var square = x => x * x; |
| 35 | assertEquals(9, square(3)); |
| 36 | |
| 37 | // Parenthesize the body to return an object literal expression |
| 38 | var key_maker = val => ({key: val}); |
| 39 | assertEquals(empty, key_maker(empty).key); |
| 40 | |
| 41 | // Statement body needs braces, must use 'return' explicitly if not void |
| 42 | var evens = [0, 2, 4, 6, 8]; |
| 43 | assertEquals([1, 3, 5, 7, 9], evens.map(v => v + 1)); |
| 44 | |
| 45 | var fives = []; |
| 46 | [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].forEach(v => { |
| 47 | if (v % 5 === 0) fives.push(v); |
| 48 | }); |
| 49 | assertEquals([5, 10], fives); |