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
|
// This file was procedurally generated from the following sources:
// - src/dstr-assignment-for-await/array-elem-iter-rtrn-close-null.case
// - src/dstr-assignment-for-await/async-generator/async-gen-decl.template
/*---
description: IteratorClose throws a TypeError when `return` returns a non-Object value (for-await-of statement in an async generator declaration)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
features: [Symbol.iterator, generators, destructuring-binding, async-iteration]
flags: [generated, async]
info: |
IterationStatement :
for await ( LeftHandSideExpression of AssignmentExpression ) Statement
1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« »,
AssignmentExpression, iterate).
2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement,
keyResult, assignment, labelSet).
13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation
[...]
5. If destructuring is true and if lhsKind is assignment, then
a. Assert: lhs is a LeftHandSideExpression.
b. Let assignmentPattern be the parse of the source text corresponding to
lhs using AssignmentPattern as the goal symbol.
[...]
AssignmentElement : DestructuringAssignmentTarget Initializer
1. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an ArrayLiteral, then
a. Let lref be the result of evaluating DestructuringAssignmentTarget.
b. ReturnIfAbrupt(lref).
[...]
ArrayAssignmentPattern : [ AssignmentElementList ]
[...]
4. If iteratorRecord.[[Done]] is false, return ? IteratorClose(iterator, result).
5. Return result.
7.4.6 IteratorClose( iterator, completion )
[...]
5. Let innerResult be Call(return, iterator, « »).
6. If completion.[[Type]] is throw, return Completion(completion).
7. If innerResult.[[Type]] is throw, return Completion(innerResult).
8. If Type(innerResult.[[Value]]) is not Object, throw a TypeError exception.
---*/
let unreachable = 0;
let iterator = {
return() {
return null;
}
};
let iterable = {
[Symbol.iterator]() {
return iterator;
}
};
let iterCount = 0;
async function * fn() {
for await ([ {}[yield] ] of [iterable]) {
unreachable += 1;
iterCount += 1;
}
}
let iter = fn();
iter.next().then(result => {
assert.sameValue(result.value, undefined);
assert.sameValue(result.done, false);
iter.return().then(() => $DONE('Promise incorrectly fulfilled.'), ({ constructor }) => {
assert.sameValue(unreachable, 0);
assert.sameValue(constructor, TypeError);
}).then($DONE, $DONE);
}, $DONE).catch($DONE);
|
