// |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-iterator.from description: > Iterator.from does not respect the iterability of any primitive except Strings info: | Iterator.from ( O ) 1. If O is a String, set O to ! ToObject(O). 2. Let iteratorRecord be ? GetIteratorFlattenable(O). includes: [compareArray.js] features: [iterator-helpers] flags: [] ---*/ function* g() { yield 0; } Number.prototype[Symbol.iterator] = function* () { let i = 0; let target = this >>> 0; while (i < target) { yield i; ++i; } }; assert.compareArray(Array.from(5), [0, 1, 2, 3, 4]); assert.throws(TypeError, function () { Iterator.from(5); }); assert.compareArray(Array.from(Iterator.from(new Number(5))), [0, 1, 2, 3, 4]); assert.compareArray(Array.from(Iterator.from('string')), ['s', 't', 'r', 'i', 'n', 'g']); const originalStringIterator = String.prototype[Symbol.iterator]; let observedType; Object.defineProperty(String.prototype, Symbol.iterator, { get() { 'use strict'; observedType = typeof this; return originalStringIterator; } }); Iterator.from(''); assert.sameValue(observedType, 'string'); Iterator.from(new String('')); assert.sameValue(observedType, 'object'); reportCompare(0, 0);