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
|
// Copyright (C) 2015 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-array.from
es6id: 22.1.2.1
description: >
`this` value of mapping function with custom `this` argument (traversed via iterator)
info: |
[...]
2. If mapfn is undefined, let mapping be false.
3. else
a. If IsCallable(mapfn) is false, throw a TypeError exception.
b. If thisArg was supplied, let T be thisArg; else let T be undefined.
c. Let mapping be true
[...]
6. If usingIterator is not undefined, then
[...]
g. Repeat
[...]
vii. If mapping is true, then
1. Let mappedValue be Call(mapfn, T, «nextValue, k»).
features: [Symbol.iterator]
---*/
var thisVals = [];
var nextResult = { done: false, value: {} };
var nextNextResult = { done: false, value: {} };
var mapFn = function() {
thisVals.push(this);
};
var items = {};
var thisVal = {};
items[Symbol.iterator] = function() {
return {
next: function() {
var result = nextResult;
nextResult = nextNextResult;
nextNextResult = { done: true };
return result;
}
};
};
Array.from(items, mapFn, thisVal);
assert.sameValue(thisVals.length, 2);
assert.sameValue(thisVals[0], thisVal, 'First iteration `this` value');
assert.sameValue(thisVals[1], thisVal, 'Second iteration `this` value');
|
