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|
// |reftest| skip-if(!this.hasOwnProperty('AsyncIterator'))
//
//
/*---
esid: pending
description: Calling `throw` on a lazy %AsyncIterator.prototype% method multiple times closes the source iterator once.
info: >
Iterator Helpers proposal 2.1.6
features: [iterator-helpers]
---*/
class TestError extends Error {}
class TestIterator extends AsyncIterator {
async next() {
return {done: false, value: 1};
}
closeCount = 0;
async return(value) {
this.closeCount++;
return {done: true, value};
}
}
async function* gen(x) { yield x; }
const methods = [
iter => iter.map(x => x),
iter => iter.filter(x => true),
iter => iter.take(Infinity),
iter => iter.drop(0),
iter => iter.asIndexedPairs(),
iter => iter.flatMap(gen),
];
(async () => {
// Call `throw` after stepping the iterator once:
for (const method of methods) {
const iter = new TestIterator();
const iterHelper = method(iter);
await iterHelper.next()
assertEq(iter.closeCount, 0);
try {
await iterHelper.throw(new TestError());
assertEq(true, false, 'Expected reject');
} catch (exc) {
assertEq(exc instanceof TestError, true);
}
assertEq(iter.closeCount, 1);
try {
await iterHelper.throw(new TestError());
assertEq(true, false, 'Expected reject');
} catch (exc) {
assertEq(exc instanceof TestError, true);
}
assertEq(iter.closeCount, 1);
}
// Call `throw` before stepping the iterator:
for (const method of methods) {
const iter = new TestIterator();
const iterHelper = method(iter);
assertEq(iter.closeCount, 0);
try {
await iterHelper.throw(new TestError());
assertEq(true, false, 'Expected reject');
} catch (exc) {
assertEq(exc instanceof TestError, true);
}
assertEq(iter.closeCount, 1);
try {
await iterHelper.throw(new TestError());
assertEq(true, false, 'Expected reject');
} catch (exc) {
assertEq(exc instanceof TestError, true);
}
assertEq(iter.closeCount, 1);
}
})();
if (typeof reportCompare == 'function')
reportCompare(0, 0);
|
