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test262/test/built-ins/Iterator/from/iterable-primitives.js

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Iterator Helpers (#2818) drop: property descriptor name length [[Prototype]] is a function is not constructible result instanceof Iterator limit is given a non-primitive that needs to be converted to a number through valueOf through toString (array) limit coercion to number throws limit converts to NaN same as limit not supplied limit behaves properly limit < number of values limit = number of values limit > number of values gets the next method from the underlying iterator only once underlying iterator has throwing next getter underlying iterator next throws when advancing past dropped items underlying iterator is advanced after calling drop underlying iterator is closed after calling drop underlying iterator is already closed underlying iterator next returns non-object underlying iterator next returns object with throwing done/value getters underlying iterator return is never called when result iterator is closed every: property descriptor name length [[Prototype]] is a function is callable is not constructible result is a Boolean predicate is non-callable iterator already exhausted called on non-object called on object with "next" method called on object with non-callable "next" method predicate returns non-Boolean predicate returns truthy for all iterated values returns true predicate returns truthy for some iterated values but then falsey for at least one iterated value returns false iteration stops iterator is closed predicate returns falsey immediately returns false iteration stops iterator is closed predicate throws every throws iterator is closed predicate throws then iterator close also throws predicate this value is undefined predicate is passed the yielded value as the first parameter and a counter as second parameter gets the next method from the iterator only once iterator has throwing next getter iterator has throwing return getter iterator next throws iterator return throws iterator next returns non-object iterator next returns object with throwing done/value getters Co-authored-by: Michael Ficarra <mficarra@shapesecurity.com> Co-authored-by: Jordan Harband <ljharb@gmail.com>
2023-06-15 17:07:41 +02:00
// 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']);