js/src/tests/test262/built-ins/Iterator/prototype/reduce/iterator-already-exhausted-no-initial-value.js


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// |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-iteratorprototype.reduce
description: >
  Iterator.prototype.reduce without an initial value throws when the iterator has already been exhausted
info: |
  %Iterator.prototype%.reduce ( reducer )

features: [iterator-helpers]
flags: []
---*/
let iterator = (function* () {})();

let { value, done } = iterator.next();
assert.sameValue(value, undefined);
assert.sameValue(done, true);

assert.throws(TypeError, function() {
  iterator.reduce(() => {});
});

iterator.reduce(() => {}, 0);

reportCompare(0, 0);