Q:

How to test email in functional test (Symfony2)

I'm trying to test email in functional test...
My source code is the same as the example of the cookbook, 
the controller :
public function sendEmailAction($name)
{
    $message = \Swift_Message::newInstance()
        ->setSubject('Hello Email')
        ->setFrom('send@example.com')
        ->setTo('recipient@example.com')
        ->setBody('You should see me from the profiler!')
    ;

    $this->get('mailer')->send($message);

    return $this->render(...);
}

And the test :
// src/Acme/DemoBundle/Tests/Controller/MailControllerTest.php
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;

class MailControllerTest extends WebTestCase
{
    public function testMailIsSentAndContentIsOk()
    {
        $client = static::createClient();

        // Enable the profiler for the next request (it does nothing if the profiler is not available)
        $client->enableProfiler();

        $crawler = $client->request('POST', '/path/to/above/action');

        $mailCollector = $client->getProfile()->getCollector('swiftmailer');

        // Check that an e-mail was sent
        $this->assertEquals(1, $mailCollector->getMessageCount());

        $collectedMessages = $mailCollector->getMessages();
        $message = $collectedMessages[0];

        // Asserting e-mail data
        $this->assertInstanceOf('Swift_Message', $message);
        $this->assertEquals('Hello Email', $message->getSubject());
        $this->assertEquals('send@example.com', key($message->getFrom()));
        $this->assertEquals('recipient@example.com', key($message->getTo()));
        $this->assertEquals(
            'You should see me from the profiler!',
            $message->getBody()
        );
    }
}

however I got this error :

PHP Fatal error:  Call to a member function getCollector() on a
  non-object

The problem comes from this line : 
$mailCollector = $client->getProfile()->getCollector('swiftmailer');

any idea ?

A:

The exception is being thrown because getProfile() returns false if the profiler is not enabled. see here.
public function getProfile()
{
    if (!$this->kernel->getContainer()->has('profiler')) {
        return false;
    }

    return $this->kernel->getContainer()->get('profiler')->loadProfileFromResponse($this->response);
}

Furthermore enableProfiler()only enables the profiler if it is registered with the service-container aka enabled. see here.
public function enableProfiler()
{
    if ($this->kernel->getContainer()->has('profiler')) {
        $this->profiler = true;
    }
}

Now you have to make sure  the profiler is enabled in the test environment. ( should normally be the default setting )
config_test.yml
framework:
   profiler:
       enabled: true

You could add something like this to your test:
$this->assertEquals($this->kernel->getContainer()->has('profiler'), true);

