test262/test/language/statements/for-await-of/async-gen-dstr-array-elem-nested-obj-yield-expr.js
Rick Waldron 9f3b85fb21 for-await-of: dstr-assignment, default template
Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
2017-05-16 13:24:41 -04:00

54 lines
1.8 KiB
JavaScript

// This file was procedurally generated from the following sources:
// - src/dstr-assignment-async-iteration/array-elem-nested-obj-yield-expr.case
// - src/dstr-assignment-async-iteration/async-generator/for-await-of-async-gen.template
/*---
description: When a `yield` token appears within the Initializer of a nested destructuring assignment and within a generator function body, it behaves as a YieldExpression. (for-await-of statement)
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.
[...]
---*/
var iter, x;
var iterCount = 0;
async function * fn() {
for await ([{ x = yield }] of [[{}]]) {
iterCount += 1;
}
}
iter = fn();
iter.next().then(iterationResult => {
assert.sameValue(iterationResult.value, undefined);
assert.sameValue(iterationResult.done, false);
assert.sameValue(x, undefined);
iter.next(4).then(iterationResult => {
assert.sameValue(iterationResult.value, undefined);
assert.sameValue(iterationResult.done, true);
assert.sameValue(x, 4);
}).then($DONE, $DONE);
});