A Middleware preventing Doctrine DBAL to change the database, useful for tests

StackRollback.php

<?php

namespace Gnugat\StackRollback;

use Doctrine\DBAL\Connection;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\HttpKernelInterface;

/**
 * Example:
 *
 * ```php
 * <?php
 *
 * namespace AppBundle\Tests\Controller;
 *
 * use Gnugat\StackRollback\Rollback;
 *
 * class ProfileControllerTest extends \PHPUnit_Framework_TestCase
 * {
 *     private $app;
 *
 *     protected function setUp()
 *     {
 *         $app = new \AppKenrel('test', false);
 *         $app->boot();
 *         $connection = $app->getContainer()->get('doctrine.dbal.default_connection');
 *         $this->app = new Rollback($app, $connection);
 *     }
 *
 *     public function testProfileCreation()
 *     {
 *         $request = new Request('/api/v1/profiles', 'POST');
 *         $response = $this->app->handle($request);
 *         $this->assertSame(201, $response->getSatusCode(), $response->getContent());
 *     }
 * }
 * ```
 */
class Rollback implements HttpKernelInterface
{
    /**
     * @var HttpKernelInterface
     */
    private $app;

    /**
     * @var Connection
     */
    private $connection;

    /**
     * @param HttpKernelInterface $app
     * @param Connection          $connection
     */
    public function __construct(HttpKernelInterface $app, Connection $connection)
    {
        $this->app = $app;
        $this->connection = $connection;
    }

    /**
     * {@inheritDoc}
     */
    public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
    {
        $this->connection->beginTransaction();
        $response = $this->app->handle($request, $type, $catch);
        $this->connection->rollback();

        return $response;
    }
}