1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
<!DOCTYPE html>
<title>Custom Elements: [HTMLConstructor] derives prototype from NewTarget</title>
<meta name="author" title="Domenic Denicola" href="mailto:d@domenic.me">
<meta name="help" content="https://html.spec.whatwg.org/multipage/dom.html#htmlconstructor">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../resources/custom-elements-helpers.js"></script>
<body>
<script>
"use strict";
test_with_window(w => {
let beforeDefinition = true;
const proto1 = { "proto": "number one" };
const proto2 = { "proto": "number two" };
function TestElement() {
const o = Reflect.construct(w.HTMLElement, [], new.target);
assert_equals(Object.getPrototypeOf(o), proto2,
"Must use the value returned from new.target.prototype");
assert_not_equals(Object.getPrototypeOf(o), proto1,
"Must not use the prototype stored at definition time");
}
const ElementWithDynamicPrototype = new Proxy(TestElement, {
get: function (target, name) {
if (name == "prototype")
return beforeDefinition ? proto1 : proto2;
return target[name];
}
});
w.customElements.define("test-element", ElementWithDynamicPrototype);
beforeDefinition = false;
new ElementWithDynamicPrototype();
}, "Use NewTarget's prototype, not the one stored at definition time");
test_with_window(w => {
// We have to not throw during define(), but throw during super()
let throws = false;
let err = { name: "prototype throws" };
function TestElement() {
throws = true;
assert_throws_exactly(err, () => {
Reflect.construct(w.HTMLElement, [], new.target);
});
}
const ElementWithDynamicPrototype = new Proxy(TestElement, {
get: function (target, name) {
if (throws && name == "prototype")
throw err;
return target[name];
}
});
w.customElements.define("test-element", ElementWithDynamicPrototype);
new ElementWithDynamicPrototype();
}, "Rethrow any exceptions thrown while getting the prototype");
[null, undefined, 5, "string"].forEach(function (notAnObject) {
test_with_window(w => {
// We have to return an object during define(), but not during super()
let returnNotAnObject = false;
function TestElement() {
const o = Reflect.construct(w.HTMLElement, [], new.target);
assert_equals(Object.getPrototypeOf(new.target), window.Function.prototype);
assert_equals(Object.getPrototypeOf(o), window.HTMLElement.prototype,
"Must use the HTMLElement from the realm of NewTarget");
assert_not_equals(Object.getPrototypeOf(o), w.HTMLElement.prototype,
"Must not use the HTMLElement from the realm of the active function object (w.HTMLElement)");
return o;
}
const ElementWithDynamicPrototype = new Proxy(TestElement, {
get: function (target, name) {
if (name == "prototype")
return returnNotAnObject ? notAnObject : {};
return target[name];
}
});
w.customElements.define("test-element", ElementWithDynamicPrototype);
returnNotAnObject = true;
new ElementWithDynamicPrototype();
}, "If prototype is not object (" + notAnObject + "), derives the fallback from NewTarget's realm (autonomous custom elements)");
test_with_window(w => {
// We have to return an object during define(), but not during super()
let returnNotAnObject = false;
function TestElement() {
const o = Reflect.construct(w.HTMLElement, [], new.target);
assert_equals(Object.getPrototypeOf(new.target), window.Function.prototype);
assert_equals(Object.getPrototypeOf(o), window.HTMLElement.prototype,
"Must use the HTMLElement from the realm of NewTarget");
assert_not_equals(Object.getPrototypeOf(o), w.HTMLElement.prototype,
"Must not use the HTMLElement from the realm of the active function object (w.HTMLElement)");
return o;
}
// Create the proxy in the subframe, which should not affect what our
// prototype ends up as.
const ElementWithDynamicPrototype = new w.Proxy(TestElement, {
get: function (target, name) {
if (name == "prototype")
return returnNotAnObject ? notAnObject : {};
return target[name];
}
});
w.customElements.define("test-element", ElementWithDynamicPrototype);
returnNotAnObject = true;
new ElementWithDynamicPrototype();
}, "If prototype is not object (" + notAnObject + "), derives the fallback from NewTarget's GetFunctionRealm (autonomous custom elements)");
});
</script>
</body>
|
