added new SessionChecker that guards the session is not started in th…

…e FE API

packages/frontend-api/src/Component/SessionChecker/SessionChecker.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shopsys\FrontendApiBundle\Component\SessionChecker;
+
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
+
+class SessionChecker
+{
+    /**
+     * @param \Symfony\Component\HttpKernel\Event\ResponseEvent $event
+     */
+    public function onKernelResponse(ResponseEvent $event): void
+    {
+        $request = $event->getRequest();
+        if (!$request->hasSession() || !$request->getSession()->isStarted() || !str_contains($request->getRequestUri(), 'graphql')) {
+            return;
+        }
+        $response = $event->getResponse();
+        $response->setContent('Session must not be started in the FE API. Check your code, please');
+    }
+}

packages/frontend-api/src/Resources/config/services.yaml

@@ -39,3 +39,7 @@ services:
 
     Lcobucci\JWT\Configuration:
         factory: ['@Shopsys\FrontendApiBundle\Model\Token\JwtConfigurationFactory', create]
+
+    Shopsys\FrontendApiBundle\Component\SessionChecker\SessionChecker:
+        tags:
+            - { name: kernel.event_listener, event: kernel.response, method: onKernelResponse, priority: -999 } # must be run before the session is closed (in Symfony\Component\HttpKernel\EventListener\SessionListener::onKernelResponse)