/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as assert from 'assert';
import { Iterable } from 'vs/base/common/iterator';

suite('Iterable', function () {

	const customIterable = new class {

		*[Symbol.iterator]() {
			yield 'one';
			yield 'two';
			yield 'three';
		}
	};

	test('first', function () {

		assert.strictEqual(Iterable.first([]), undefined);
		assert.strictEqual(Iterable.first([1]), 1);
		assert.strictEqual(Iterable.first(customIterable), 'one');
		assert.strictEqual(Iterable.first(customIterable), 'one'); // fresh
	});

	test('wrap', function () {
		assert.deepStrictEqual([...Iterable.wrap(1)], [1]);
		assert.deepStrictEqual([...Iterable.wrap([1, 2, 3])], [1, 2, 3]);
	});
});
