mirror of https://github.com/tc39/test262.git
52 lines
1000 B
JavaScript
52 lines
1000 B
JavaScript
// Copyright (C) 2023 Michael Ficarra. All rights reserved.
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// This code is governed by the BSD license found in the LICENSE file.
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/*---
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esid: sec-iterator.from
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description: >
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Iterator.from falls back to treating its parameter as an iterator if the Symbol.iterator property is null/undefined
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info: |
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Iterator.from ( O )
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includes: [compareArray.js]
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features: [iterator-helpers]
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flags: []
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---*/
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function* g() {
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yield 0;
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yield 1;
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yield 2;
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}
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let iter = (function () {
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let n = g();
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return {
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[Symbol.iterator]: 0,
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next: () => n.next(),
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};
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})();
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assert.throws(TypeError, function () {
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Iterator.from(iter);
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});
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iter = (function () {
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let n = g();
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return {
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[Symbol.iterator]: null,
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next: () => n.next(),
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};
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})();
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assert.compareArray(Array.from(Iterator.from(iter)), [0, 1, 2]);
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iter = (function () {
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let n = g();
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return {
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[Symbol.iterator]: undefined,
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next: () => n.next(),
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};
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})();
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assert.compareArray(Array.from(Iterator.from(iter)), [0, 1, 2]);
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