// Copyright (C) 2025 André Bargull. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-iterator.zip description: > Handle abrupt completions during iterables iteration. info: | Iterator.zip ( iterables [ , options ] ) ... 12. Repeat, while next is not done, a. Set next to Completion(IteratorStepValue(inputIter)). b. IfAbruptCloseIterators(next, iters). ... IfAbruptCloseIterators ( value, iteratorRecords ) 1. Assert: value is a Completion Record. 2. If value is an abrupt completion, return ? IteratorCloseAll(iteratorRecords, value). 3. Else, set value to value.[[Value]]. IteratorCloseAll ( iters, completion ) 1. For each element iter of iters, in reverse List order, do a. Set completion to Completion(IteratorClose(iter, completion)). 2. Return ? completion. IteratorClose ( iteratorRecord, completion ) 1. Assert: iteratorRecord.[[Iterator]] is an Object. 2. Let iterator be iteratorRecord.[[Iterator]]. 3. Let innerResult be Completion(GetMethod(iterator, "return")). 4. If innerResult is a normal completion, then a. Let return be innerResult.[[Value]]. b. If return is undefined, return ? completion. c. Set innerResult to Completion(Call(return, iterator)). 5. If completion is a throw completion, return ? completion. ... includes: [compareArray.js] features: [joint-iteration] ---*/ class ExpectedError extends Error {} var log = []; var first = { next() { log.push("unexpected call to next method"); }, return() { // Called with the correct receiver and no arguments. assert.sameValue(this, first); assert.sameValue(arguments.length, 0); // NB: Log after above asserts, because failures aren't propagated. log.push("close first iterator"); // IteratorClose ignores new exceptions when called with a Throw completion. throw new Test262Error(); }, }; var second = { next() { log.push("unexpected call to next method"); }, return() { // Called with the correct receiver and no arguments. assert.sameValue(this, second); assert.sameValue(arguments.length, 0); // NB: Log after above asserts, because failures aren't propagated. log.push("close second iterator"); // IteratorClose ignores new exceptions when called with a Throw completion. throw new Test262Error(); }, }; var elements = [first, second]; var elementsIter = elements.values(); var iterables = { [Symbol.iterator]() { return this; }, next() { log.push("call next"); var result = elementsIter.next(); if (result.done) { throw new ExpectedError(); } return result; }, return() { // This method shouldn't be called. log.push("UNEXPECTED - close iterables iterator"); // IteratorClose ignores new exceptions when called with a Throw completion. throw new Test262Error(); }, }; assert.throws(ExpectedError, function() { Iterator.zip(iterables); }); // Ensure iterators are closed in the correct order. assert.compareArray(log, [ "call next", "call next", "call next", "close second iterator", "close first iterator", ]);