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) 2020 Alexey Shvayka. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-generator-function-definitions-runtime-semantics-evaluation
description: >
If <iterator>.throw is an object emulating `undefined` (e.g. `document.all`
in browsers), it shouldn't be treated as if it were actually `undefined` by
the yield* operator.
info: |
YieldExpression : yield * AssignmentExpression
[...]
7. Repeat,
[...]
b. Else if received.[[Type]] is throw, then
i. Let throw be ? GetMethod(iterator, "throw").
ii. If throw is not undefined, then
1. Let innerResult be ? Call(throw, iterator, « received.[[Value]] »).
[...]
4. If Type(innerResult) is not Object, throw a TypeError exception.
features: [generators, IsHTMLDDA]
---*/
var IsHTMLDDA = $262.IsHTMLDDA;
var returnCalls = 0;
var inner = {
[Symbol.iterator]() { return this; },
next() { return {done: false}; },
throw: IsHTMLDDA,
return() {
returnCalls += 1;
return {done: true};
},
};
var outer = (function* () { yield* inner; })();
outer.next();
assert.throws(TypeError, function() {
// `IsHTMLDDA` is called here with `iter` as `this` and `emptyString` as the
// sole argument, and it's specified to return `null` under these conditions.
// As `iter`'s iteration isn't ending because of a throw, the iteration
// protocol will then throw a `TypeError` because `null` isn't an object.
var emptyString = "";
outer.throw(emptyString);
});
assert.sameValue(returnCalls, 0);
reportCompare(0, 0);
|
