Throw an exception when Topic implements the wrong EventSubscriberInt…

…erface

src/Websocket/Application.php

@@ -3,6 +3,7 @@
 namespace Eole\Sandstone\Websocket;
 
 use Psr\Log\LoggerAwareTrait;
+use JMS\Serializer\EventDispatcher\EventSubscriberInterface as WrongEventSubscriberInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Security\Core\User\UserInterface;
 use Ratchet\ConnectionInterface;
@@ -120,6 +121,14 @@ private function loadTopic($topicPath)
             $this->sandstoneApplication['dispatcher']->addSubscriber($topic);
         }
 
+        // debug purpose only. Sometimes I use the wrong namespace (JMS one), and it's hard to debug.
+        if ($topic instanceof WrongEventSubscriberInterface) {
+            throw new \LogicException(
+                get_class($topic).' seems to implements the wrong EventSubscriberInterface. '.
+                'Use the Symfony one, not the JMS one.'
+            );
+        }
+
         return $topic;
     }
 

tests/Unit/EventForwarderTest.php → tests/Unit/Push/EventForwarderTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Eole\Sandstone\Tests\Unit;
+namespace Eole\Sandstone\Tests\Unit\Push;
 
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Eole\Sandstone\Push\PushServerInterface;

tests/Unit/Websocket/ApplicationTest.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Eole\Sandstone\Tests\Unit\Websocket;
+
+use Eole\Sandstone\Serializer\ServiceProvider as SerializerServiceProvider;
+use Eole\Sandstone\Websocket\Routing\TopicRouter;
+use Eole\Sandstone\Websocket\Application as WebsocketApplication;
+use Eole\Sandstone\Application;
+
+class ApplicationTest extends \PHPUnit_Framework_TestCase
+{
+    public function testLoadTopicThrowExceptionWhenImplementingTheWrongEventDispatcherInterface()
+    {
+        $app = new Application();
+        $websocketAppClass = new \ReflectionClass(WebsocketApplication::class);
+        $method = $websocketAppClass->getMethod('loadTopic');
+        $method->setAccessible(true);
+        $websocketApp = $websocketAppClass->newInstance($app);
+
+        $app->register(new SerializerServiceProvider());
+
+        $app['sandstone.websocket.router'] = function () {
+            $wrongTopic = new WrongTopic('my-topic');
+            $topicRouterMock = $this->createMock(TopicRouter::class);
+
+            $topicRouterMock
+                ->method('loadTopic')
+                ->willReturn($wrongTopic)
+            ;
+
+            return $topicRouterMock;
+        };
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('WrongTopic seems to implements the wrong EventSubscriberInterface');
+
+        $method->invokeArgs($websocketApp, ['my-topic']);
+    }
+}

tests/Unit/Websocket/WrongTopic.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Eole\Sandstone\Tests\Unit\Websocket;
+
+use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
+use Eole\Sandstone\Websocket\Topic;
+
+class WrongTopic extends Topic implements EventSubscriberInterface
+{
+    public static function getSubscribedEvents()
+    {
+        return [];
+    }
+}