fix: type mismatches and handle nullable values

src/Controller/Admin/System/EmailText/EditController.php

@@ -32,18 +32,15 @@ class EditController extends AbstractController
     public function index(EmailTextKey $key, Request $request): Response
     {
         $definition = $this->catalog->get($key);
-        $emailText = $this->emailTextRepository->findByKey($key);
-        $isNew = null === $emailText;
+        $existing = $this->emailTextRepository->findByKey($key);
 
         // Editing a mail for the first time starts from the delivered wording rather than
         // from an empty form, so an admin adjusts a sentence instead of rewriting the mail.
-        if (true === $isNew) {
-            $emailText = (new EmailText($key))
-                ->setSubject($definition->defaultSubject)
-                ->setHeadline($definition->defaultHeadline)
-                ->setBody($definition->defaultBody)
-            ;
-        }
+        $emailText = $existing ?? (new EmailText($key))
+            ->setSubject($definition->defaultSubject)
+            ->setHeadline($definition->defaultHeadline)
+            ->setBody($definition->defaultBody)
+        ;
 
         $form = $this->createForm(EmailTextType::class, $emailText, [
             'definition' => $definition,
@@ -51,10 +48,7 @@ class EditController extends AbstractController
         $form->handleRequest($request);
 
         if ($form->isSubmitted() && $form->isValid()) {
-            if (true === $isNew) {
-                $this->entityManager->persist($emailText);
-            }
-
+            $this->entityManager->persist($emailText);
             $this->entityManager->flush();
 
             $this->addFlash('success', 'Der E-Mail-Text wurde aktualisiert');

src/Controller/Admin/Teamer/MailingController.php

@@ -2,6 +2,7 @@
 
 namespace App\Controller\Admin\Teamer;
 
+use App\Controller\Traits\AuthenticatedUserTrait;
 use App\Controller\Traits\ReturnUrlTrait;
 use App\Email\MailBodyRenderer;
 use App\Form\TeamerMailingType;
@@ -21,6 +22,7 @@ use Symfony\Component\Security\Http\Attribute\IsGranted;
 
 class MailingController extends AbstractController
 {
+    use AuthenticatedUserTrait;
     use ReturnUrlTrait;
 
     public function __construct(
@@ -47,7 +49,7 @@ class MailingController extends AbstractController
         }
 
         if ($form->isSubmitted() && $form->isValid()) {
-            $this->mailingService->sendPreview($form->getData(), $this->getUser());
+            $this->mailingService->sendPreview($form->getData(), $this->getAuthenticatedUser());
 
             $this->addFlash('success', sprintf(
                 'Die Vorschau wurde an %s gesendet',
@@ -164,7 +166,7 @@ class MailingController extends AbstractController
      */
     private function renderPreview(TeamerMailingDto $mailingDto): array
     {
-        $values = $this->mailingService->placeholderValuesForUser($this->getUser());
+        $values = $this->mailingService->placeholderValuesForUser($this->getAuthenticatedUser());
 
         return [
             'subject' => $this->mailingService->render($mailingDto->getSubject(), $values),

src/Controller/Traits/AuthenticatedUserTrait.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Controller\Traits;
+
+use App\Entity\User;
+use Symfony\Component\Security\Core\Exception\AuthenticationException;
+
+trait AuthenticatedUserTrait
+{
+    public function getAuthenticatedUser(): User
+    {
+        $user = $this->getUser();
+
+        if (null === $user) {
+            throw new AuthenticationException();
+        }
+
+        return $user;
+    }
+}