add a test for swiftmailerServiceProvider app->finish event

tests/Silex/Tests/Provider/SwiftmailerServiceProviderTest.php

@@ -14,6 +14,9 @@ namespace Silex\Tests\Provider;
 use Silex\Application;
 use Silex\Provider\SwiftmailerServiceProvider;
 
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
 class SwiftmailerServiceProviderTest extends \PHPUnit_Framework_TestCase
 {
     public function setUp()
@@ -32,4 +35,54 @@ class SwiftmailerServiceProviderTest extends \PHPUnit_Framework_TestCase
 
         $this->assertInstanceOf('Swift_Mailer', $app['mailer']);
     }
+
+    public function testSwiftMailerSendsMailsOnFinish()
+    {
+        $app = new Application();
+        $app->register(new SwiftmailerServiceProvider(), array(
+            'swiftmailer.class_path'  => __DIR__.'/../../../../vendor/swiftmailer/swiftmailer/lib/classes',
+        ));
+
+        $app['swiftmailer.transport'] = $app->share(function () use ($app) {
+           return new \Swift_Transport_SpoolTransport($app['swiftmailer.transport.eventdispatcher'], new \Swift_MemorySpool());
+        });
+
+        $test = $this;
+
+        /**
+         * This gets executed before SwiftmailerServiceProvider $app->finish thanks to higher priority
+         * flushQueue should return 1 if spool has not been flushed
+         */
+        $app->finish(function() use ($app, $test) {
+            $test->assertEquals(1, $app['swiftmailer.spooltransport']->getSpool()->flushQueue($app['swiftmailer.transport']));
+            /**
+             * We add a new message that should be flushed with $app->finish()
+             */
+            $app['mailer']->send(\Swift_Message::newInstance());
+        }, 1);
+
+        /**
+         * This gets executed after SwiftmailerServiceProvider $app->finish thanks to higher priority
+         * flushQueue should return 0 even having added a message in method above
+         */
+        $app->finish(function() use ($app, $test) {
+            $test->assertEquals(0, $app['swiftmailer.spooltransport']->getSpool()->flushQueue($app['swiftmailer.transport']));
+        }, -1);
+
+        $app->get('/', function() use ($app) {
+            $app['mailer']->send(\Swift_Message::newInstance());
+            return new SendMailsResponse('should send e-mails');
+        });
+
+        $request = Request::create('/');
+        $app->run($request);
+    }
+}
+
+class SendMailsResponse extends Response
+{
+    public function send()
+    {
+        // do nothing
+    }
 }