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// |reftest| async
// This file was procedurally generated from the following sources:
// - src/dstr-assignment-for-await/array-elem-init-yield-expr.case
// - src/dstr-assignment-for-await/async-generator/async-gen-decl.template
/*---
description: When a `yield` token appears within the Initializer of an AssignmentElement within a generator function body, it behaves as a YieldExpression. (for-await-of statement in an async generator declaration)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
features: [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.
[...]
---*/
let value = [];
let x;
let iterCount = 0;
async function * fn() {
for await ([ x = yield ] of [[]]) {
iterCount += 1;
}
}
let iter = fn();
iter.next().then(result => {
assert.sameValue(result.value, undefined);
assert.sameValue(result.done, false);
assert.sameValue(x, undefined);
iter.next(4).then(result => {
assert.sameValue(result.value, undefined);
assert.sameValue(result.done, true);
assert.sameValue(x, 4);
}).then($DONE, $DONE);
}, $DONE).catch($DONE);
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