Teste funcional como usuário autenticado

protected static function createAuthenticatedClient($username, $options = [], $server = [])
{
$client
= static::createClient($options, $server);
$container
= $client->getContainer();

$session
= $container->get('session');
/** @var $userManager FOSUserBundleDoctrineUserManager */
$userManager
= $container->get('fos_user.user_manager');
/** @var $loginManager FOSUserBundleSecurityLoginManager */
$loginManager
= $container->get('fos_user.security.login_manager');
$firewallName
= $container->getParameter('fos_user.firewall_name');

$user
= $userManager->findUserBy(array('username' => $username));
$loginManager
->loginUser($firewallName, $user);

// save the login token into the session and put it in a cookie
$container
->get('session')->set(
'_security_' . $firewallName,
serialize
($container->get('security.context')->getToken())
);
$container
->get('session')->save();
$client
->getCookieJar()->set(new Cookie($session->getName(), $session->getId()));

return $client;
}

Fonte: https://advancingusability.wordpress.com/2013/11/15/functional-testing-with-authentication-and-symfony-2-3-fosuserbundle/