filter-second-unit-test.php

<?php

/**
 * @dataProvider usersProvider
 */
public function test_it_filters_adults(array $users, int $expectedCount)
{
    $filter = new UserFilterAge();

    $this->assertCount($expectedCount, $filter($users));
}

public function usersProvider()
{
    return [
        [
            [
                ['age' => 15],
                ['age' => 20],
            ],
            1
        ],
        [
            [
                ['age' => 18],
            ],
            1
        ]
    ];
}