A simple and modular way to use Doctrines Data-Fixtures in Symfony2 Unit-Tests.

AppWebTestCase.php

<?php

namespace Acme\CoreBundle\Tests;

use Doctrine\ORM\Tools\SchemaTool;
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
use Doctrine\Common\DataFixtures\FixtureInterface;

class AppWebTestCase extends WebTestCase
{
    /** @var \Doctrine\ORM\EntityManager */
    public $em;
    /** @var \Symfony\Component\DependencyInjection\ContainerInterface $container */
    public $container;

    private $fixturesRegistry = array();

    /**
     * {@inheritDoc}
     */
    public function setUp()
    {
        static::$kernel = static::createKernel();
        static::$kernel->boot();

        $this->container = static::$kernel->getContainer();
        $this->em = $this->container
            ->get('doctrine')
            ->getManager();

        $this->generateSchema();
        $this->loadFixtures();
    }

    public function addFixture(FixtureInterface $fixture) {
        $this->fixturesRegistry[] = $fixture;
    }

    /**
     * @return null
     */
    protected function generateSchema()
    {
        $metadatas = $this->getMetadatas();

        if (!empty($metadatas)) {
            $tool = new SchemaTool($this->em);
            $tool->dropSchema($metadatas);
            $tool->createSchema($metadatas);
        }
    }

    /**
     * @return array
     */
    protected function getMetadatas()
    {
        return $this->em->getMetadataFactory()->getAllMetadata();
    }

    /**
     * {@inheritDoc}
     */
    protected function tearDown()
    {
        parent::tearDown();
        $this->em->close();
    }

    /**
     * Load fixtures from FixtureRegistry
     */
    protected function loadFixtures()
    {
        /** @var FixtureInterface $fixture */
        foreach ($this->fixturesRegistry as $fixture) {
            $fixture->load($this->em);
        }
    }
}

config_test.yml

# /app/config/config_test.php

# Make PHPUnit use it's own database.
doctrine:
    dbal:
        dbname:   "%database_name%_test"

YourTest.php

<?php
namespace Acme\CoreBundle\Tests\Service;

use Acme\CoreBundle\Tests\AppWebTestCase;
use Acme\CoreBundle\DataFixtures\LoadUsers;
use Acme\OtherBundle\DataFixtures\LoadFooBar;

class NotificationComposerTest extends AppWebTestCase
{

    /**
     * {@inheritDoc}
     */
    public function setUp()
    {
        $this->addFixture(new LoadUsers());
        $this->addFixture(new LoadFooBar());

        parent::setUp();
    }

    public function testWhateverYouWant()
    {
        // Perform your tests here
    }
}