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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --harmony-proxies
function TestBasics() {
var log = [];
var proxy = new Proxy({}, {
get: function(target, key) {
log.push("get " + String(key));
if (key === 'x') return 1;
},
has: function(target, key) {
log.push("has " + String(key));
if (key === 'x') return true;
return false;
}
});
var x = 'local';
with (proxy) {
assertEquals(1, x);
}
assertEquals(['has assertEquals', 'has x', 'get Symbol(Symbol.unscopables)',
'get x'], log);
}
TestBasics();
function TestInconsistent() {
var log = [];
var proxy = new Proxy({}, {
get: function(target, key) {
log.push("get " + String(key));
return undefined;
},
has: function(target, key) {
log.push("has " + String(key));
if (key === 'x') return true;
return false;
}
});
var x = 'local';
with (proxy) {
assertEquals(void 0, x);
}
assertEquals(['has assertEquals', 'has x', 'get Symbol(Symbol.unscopables)',
'get x'], log);
}
TestInconsistent();
function TestUseProxyAsUnscopables() {
var x = 1;
var object = {
x: 2
};
var calls = 0;
var proxy = new Proxy({}, {
has: function() {
assertUnreachable();
},
get: function(target, key) {
assertEquals('x', key);
calls++;
return calls === 2 ? true : undefined;
}
});
object[Symbol.unscopables] = proxy;
with (object) {
assertEquals(2, x);
assertEquals(1, x);
}
// HasBinding, HasBinding
assertEquals(2, calls);
}
TestUseProxyAsUnscopables();
function TestThrowInHasUnscopables() {
var x = 1;
var object = {
x: 2
};
function CustomError() {}
var calls = 0;
var proxy = new Proxy({}, {
has: function() {
assertUnreachable();
},
get: function(target, key) {
if (calls++ === 0) {
throw new CustomError();
}
assertUnreachable();
}
});
object[Symbol.unscopables] = proxy;
assertThrows(function() {
with (object) {
x;
}
}, CustomError);
}
TestThrowInHasUnscopables();
var global = this;
function TestGlobalShouldIgnoreUnscopables() {
global.x = 1;
var proxy = new Proxy({}, {
get: function() {
assertUnreachable();
},
has: function() {
assertUnreachable();
}
});
global[Symbol.unscopables] = proxy;
assertEquals(1, global.x);
assertEquals(1, x);
global.x = 2;
assertEquals(2, global.x);
assertEquals(2, x);
x = 3;
assertEquals(3, global.x);
assertEquals(3, x);
}
TestGlobalShouldIgnoreUnscopables();
|
