endtoend-test-psl/tests/Psl/Iter/CountTest.php

<?php

declare(strict_types=1);

namespace Psl\Tests\Iter;

use PHPUnit\Framework\TestCase;
use Psl\Collection;
use Psl\Iter;

class CountTest extends TestCase
{
    /**
     * @dataProvider provideData
     */
    public function testCount(int $expected, iterable $iterable): void
    {
        self::assertSame($expected, Iter\count($iterable));
    }

    public function provideData(): iterable
    {
        yield [0, []];
        yield [1, [null]];
        yield [3, [1, 2, 3]];
        yield [10, Iter\range(1, 10)];
        yield [1, (fn () => yield 1 => 2)()];
        yield [21, new Collection\Vector(Iter\range(0, 100, 5))];
    }
}