From 60580a0042aad7db962d6bf330ff20316b847d77 Mon Sep 17 00:00:00 2001 From: Michael Ficarra Date: Thu, 29 May 2025 16:28:33 +0200 Subject: [PATCH] add test for tc39/proposal-iterator-sequencing#19 (#4485) --- .../Iterator/concat/get-value-after-done.js | 47 +++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 test/built-ins/Iterator/concat/get-value-after-done.js diff --git a/test/built-ins/Iterator/concat/get-value-after-done.js b/test/built-ins/Iterator/concat/get-value-after-done.js new file mode 100644 index 0000000000..0ddda9b652 --- /dev/null +++ b/test/built-ins/Iterator/concat/get-value-after-done.js @@ -0,0 +1,47 @@ +// Copyright (C) 2025 Michael Ficarra. All rights reserved. +// This code is governed by the BSD license found in the LICENSE file. + +/*--- +esid: sec-iterator.concat +description: > + Iterator.concat accesses the value of a done IteratorResult, matching the behaviour of yield* +info: | + Iterator.concat ( ...items ) + + ... + 3. Let closure be a new Abstract Closure with no parameters that captures iterables and performs the following steps when called: + a. For each Record iterable of iterables, do + ... + v. Repeat, while innerAlive is true, + 1. Let iteratorResult be ? IteratorNext(iteratorRecord). + 2. Let done be Completion(IteratorComplete(iteratorResult)). + 3. If done is a throw completion, then + a. Set iteratorRecord.[[Done]] to true. + b. Return ? done. + 4. Set done to ! done. + 5. If done is true, then + a. Set iteratorRecord.[[Done]] to true. + b. Perform ? IteratorValue(iteratorResult). + ... +features: [iterator-sequencing] +---*/ + +let valueAccesses = 0; +let iter = { + [Symbol.iterator]() { + return { + next() { + return { + get value() { + ++valueAccesses; + }, + done: true, + }; + }, + }; + } +}; + +Array.from(Iterator.concat(iter, iter, iter)); + +assert.sameValue(valueAccesses, 3, 'Iterator.concat also accesses value getter after each iterator is done');