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1 // Copyright 2016 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-instanceof | |
6 | |
7 // Make sure it's an error if @@hasInstance isn't a function. | |
8 (function() { | |
9 var F = {}; | |
10 F[Symbol.hasInstance] = null; | |
11 assertThrows(function() { 0 instanceof F; }, TypeError); | |
12 })(); | |
13 | |
14 // Make sure the result is coerced to boolean. | |
15 (function() { | |
16 var F = {}; | |
17 F[Symbol.hasInstance] = function() { return undefined; }; | |
18 assertEquals(0 instanceof F, false); | |
19 F[Symbol.hasInstance] = function() { return null; }; | |
20 assertEquals(0 instanceof F, false); | |
21 F[Symbol.hasInstance] = function() { return true; }; | |
22 assertEquals(0 instanceof F, true); | |
23 })(); | |
24 | |
25 // Make sure if @@hasInstance throws, we catch it. | |
26 (function() { | |
27 var F = {}; | |
28 F[Symbol.hasInstance] = function() { throw new Error("always throws"); } | |
29 try { | |
30 0 instanceof F; | |
31 } catch (e) { | |
32 assertEquals(e.message, "always throws"); | |
33 } | |
34 })(); | |
35 | |
36 // @@hasInstance works for bound functions. | |
37 (function() { | |
38 var BC = function() {}; | |
39 var bc = new BC(); | |
40 var bound = BC.bind(); | |
41 assertEquals(bound[Symbol.hasInstance](bc), true); | |
42 assertEquals(bound[Symbol.hasInstance]([]), false); | |
43 })(); | |
44 | |
45 // if OrdinaryHasInstance is passed a non-callable receiver, return false. | |
46 assertEquals(Function.prototype[Symbol.hasInstance].call(Array, []), true); | |
47 assertEquals(Function.prototype[Symbol.hasInstance].call({}, {}), false); | |
48 | |
49 // OrdinaryHasInstance passed a non-object argument returns false. | |
50 assertEquals(Function.prototype[Symbol.hasInstance].call(Array, 0), false); | |
51 | |
52 // Cannot assign to @@hasInstance with %FunctionPrototype%. | |
53 (function() { | |
54 "use strict"; | |
55 function F() {} | |
56 assertThrows(function() { F[Symbol.hasInstance] = (v) => v }, TypeError); | |
57 })(); | |
58 | |
59 // Check correct invocation of @@hasInstance handler on function instance. | |
60 (function() { | |
61 function F() {} | |
62 var counter = 0; | |
63 var proto = Object.getPrototypeOf(F); | |
64 Object.setPrototypeOf(F, null); | |
65 F[Symbol.hasInstance] = function(v) { ++counter; return true }; | |
66 Object.setPrototypeOf(F, proto); | |
67 assertTrue(1 instanceof F); | |
68 assertEquals(1, counter); | |
69 })(); | |
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