integration-transactions.md

title	Database Transactions for Test Cleanup
impact	MEDIUM
impactDescription	Fast, reliable database state reset
tags	integration, database, transactions, cleanup, rollback

Database Transactions for Test Cleanup

Impact: MEDIUM (fast, reliable database state reset)

Wrap each database test in a transaction and roll back after the test completes. This is much faster than truncating tables or reloading fixtures, and guarantees a clean state for the next test.

Most frameworks provide this out of the box (e.g., Symfony's KernelTestCase with dama/doctrine-test-bundle).

Incorrect (manual cleanup with DELETE statements):

<?php

declare(strict_types=1);

namespace App\Tests;

use App\UserRepository;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;

final class UserRepositoryTest extends TestCase
{
    protected function tearDown(): void
    {
        // Slow and error-prone manual cleanup
        $this->getConnection()->exec('DELETE FROM users');
        $this->getConnection()->exec('DELETE FROM orders');
        $this->getConnection()->exec('ALTER TABLE users AUTO_INCREMENT = 1');
    }

    #[Test]
    public function it_persists_user(): void
    {
        // ...
    }
}

Correct (transaction rollback via extension):

<!-- phpunit.xml -->
<extensions>
    <bootstrap class="DAMA\DoctrineTestBundle\PHPUnit\PHPUnitExtension"/>
</extensions>

<?php

declare(strict_types=1);

namespace App\Tests;

use App\Entity\User;
use Doctrine\ORM\EntityManagerInterface;
use PHPUnit\Framework\Attributes\Test;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;

final class UserRepositoryTest extends KernelTestCase
{
    #[Test]
    public function it_persists_user(): void
    {
        $em = static::getContainer()->get(EntityManagerInterface::class);
        $user = new User('John', 'john@example.com');

        $em->persist($user);
        $em->flush();

        $this->assertNotNull($user->getId());
        // Transaction is automatically rolled back after this test
    }
}

Reference: DAMA Doctrine Test Bundle