SurrogateListener example

use Symfony\Component\HttpKernel\HttpCache\Esi;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\KernelEvents;

class SurrogateListenerTest extends TestCase
{
    public function testFilterDoesNothingForSubRequests()
    {
        $dispatcher = new EventDispatcher();
        $kernel = $this->createMock(HttpKernelInterface::class);
        $response = new Response('foo <esi:include src="" />');
        $listener = new SurrogateListener(new Esi());

        $dispatcher->addListener(KernelEvents::RESPONSE, $listener->onKernelResponse(...));
        $event = new ResponseEvent($kernel, new Request(), HttpKernelInterface::SUB_REQUEST, $response);
        $dispatcher->dispatch($event, KernelEvents::RESPONSE);

        $this->assertEquals('', $event->getResponse()->headers->get('Surrogate-Control'));
    }

    public function testFilterWhenThereIsSomeEsiIncludes()
    {
        $dispatcher = new EventDispatcher();