How to use PHPUnit's @dataProvider in extended TestCase

0_README.md

PHPUnit @dataProvider simply doesn't work!

If you are using subclasses of PHPUnit's TestCase, you should call parent::__construct in order to benefit @dataProviders. But the tricky part is that TestCase::_construct receives some arguments. So, you should define them in your inherited class and pass them to the parent::__construct.

read more

1_DataProviderTest.php

<?php

namespace Tests\Feature;

use Tests\TestCase;

class DataProviderTest extends TestCase
{
    /**
     * @dataProvider additionProvider
     */
    public function testAdd($a, $b, $expected)
    {
        $this->assertSame($expected, $a + $b);
    }

    public function additionProvider()
    {
        return [
            [0, 0, 0],
            [0, 1, 1],
            [1, 0, 1],
            [1, 1, 3]
        ];
    }
}

2_buggyBaseTestCase.php

<?php

namespace Tests;

use Illuminate\Foundation\Testing\TestCase as BaseTestCase;

class TestCase extends BaseTestCase
{
    use CreatesApplication;

    protected $headers = ['accept' => 'application/json'];

    public function __construct()
    {
       parent::__construct();    // Illuminate\Foundation\Testing\TestCase has no __construct, so it bubbles up to PHPUnit\Framework\TestCase. But without any args
    }
}

3_workingBaseTestCase.php

<?php

namespace Tests;

use Illuminate\Foundation\Testing\TestCase as BaseTestCase;

 class TestCase extends BaseTestCase
{
    use CreatesApplication;

    protected $headers = ['accept' => 'application/json'];

    public function __construct(?string $name = null, array $data = [], string $dataName = '')
    {
        parent::__construct($name, $data, $dataName);
    }
}