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// |reftest| shell-option(--enable-iterator-helpers) skip-if(!this.hasOwnProperty('Iterator')||!xulRuntime.shell) -- iterator-helpers is not enabled unconditionally, requires shell-options
// Copyright (C) 2023 Michael Ficarra. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-iteratorprototype.filter
description: >
Gets the next method from the underlying iterator only once
info: |
%Iterator.prototype%.filter ( predicate )
1. Let iterated be ? GetIteratorDirect(this value).
features: [iterator-helpers]
flags: []
---*/
let nextGets = 0;
let nextCalls = 0;
class CountingIterator extends Iterator {
get next() {
++nextGets;
let iter = (function* () {
for (let i = 1; i < 5; ++i) {
yield i;
}
})();
return function () {
++nextCalls;
return iter.next();
};
}
}
let iterator = new CountingIterator();
assert.sameValue(nextGets, 0);
assert.sameValue(nextCalls, 0);
for (const value of iterator.filter(() => false));
assert.sameValue(nextGets, 1);
assert.sameValue(nextCalls, 5);
reportCompare(0, 0);
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