diff --git a/rector.php b/rector.php
index b90d120a..db559491 100644
--- a/rector.php
+++ b/rector.php
@@ -5,6 +5,8 @@ declare(strict_types=1);
 use Rector\CodeQuality\Rector\Class_\InlineConstructorDefaultToPropertyRector;
 use Rector\Config\RectorConfig;
 use Rector\Doctrine\Set\DoctrineSetList;
+use Rector\PHPUnit\Set\PHPUnitLevelSetList;
+use Rector\PHPUnit\Set\PHPUnitSetList;
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Symfony\Set\SymfonyLevelSetList;
@@ -42,5 +44,10 @@ return static function (RectorConfig $rectorConfig): void {
         //Doctrine rules
         DoctrineSetList::ANNOTATIONS_TO_ATTRIBUTES,
         DoctrineSetList::DOCTRINE_CODE_QUALITY,
+
+        //PHPUnit rules
+        PHPUnitLevelSetList::UP_TO_PHPUNIT_90,
+        PHPUnitSetList::ANNOTATIONS_TO_ATTRIBUTES,
+        PHPUnitSetList::PHPUNIT_CODE_QUALITY,
     ]);
 };
diff --git a/src/Controller/AdminPages/AttachmentTypeController.php b/src/Controller/AdminPages/AttachmentTypeController.php
index 0b85f4a0..426e773c 100644
--- a/src/Controller/AdminPages/AttachmentTypeController.php
+++ b/src/Controller/AdminPages/AttachmentTypeController.php
@@ -36,6 +36,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\AttachmentTypeControllerTest
+ */
 #[Route(path: '/attachment_type')]
 class AttachmentTypeController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/CategoryController.php b/src/Controller/AdminPages/CategoryController.php
index 622de1eb..153d46f3 100644
--- a/src/Controller/AdminPages/CategoryController.php
+++ b/src/Controller/AdminPages/CategoryController.php
@@ -35,6 +35,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\CategoryControllerTest
+ */
 #[Route(path: '/category')]
 class CategoryController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/FootprintController.php b/src/Controller/AdminPages/FootprintController.php
index 8edd0b06..d1414d2a 100644
--- a/src/Controller/AdminPages/FootprintController.php
+++ b/src/Controller/AdminPages/FootprintController.php
@@ -36,6 +36,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\FootprintControllerTest
+ */
 #[Route(path: '/footprint')]
 class FootprintController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/LabelProfileController.php b/src/Controller/AdminPages/LabelProfileController.php
index b89858dd..ee754436 100644
--- a/src/Controller/AdminPages/LabelProfileController.php
+++ b/src/Controller/AdminPages/LabelProfileController.php
@@ -35,6 +35,9 @@ use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
+/**
+ * @see \App\Tests\Controller\AdminPages\LabelProfileControllerTest
+ */
 #[Route(path: '/label_profile')]
 class LabelProfileController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/ManufacturerController.php b/src/Controller/AdminPages/ManufacturerController.php
index c6db73ee..2a97d3f3 100644
--- a/src/Controller/AdminPages/ManufacturerController.php
+++ b/src/Controller/AdminPages/ManufacturerController.php
@@ -35,6 +35,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\ManufacturerControllerTest
+ */
 #[Route(path: '/manufacturer')]
 class ManufacturerController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/MeasurementUnitController.php b/src/Controller/AdminPages/MeasurementUnitController.php
index b8a566ec..993c5dad 100644
--- a/src/Controller/AdminPages/MeasurementUnitController.php
+++ b/src/Controller/AdminPages/MeasurementUnitController.php
@@ -36,6 +36,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\MeasurementUnitControllerTest
+ */
 #[Route(path: '/measurement_unit')]
 class MeasurementUnitController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/StorelocationController.php b/src/Controller/AdminPages/StorelocationController.php
index 36e8da34..7a9850ab 100644
--- a/src/Controller/AdminPages/StorelocationController.php
+++ b/src/Controller/AdminPages/StorelocationController.php
@@ -35,6 +35,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\StorelocationControllerTest
+ */
 #[Route(path: '/store_location')]
 class StorelocationController extends BaseAdminController
 {
diff --git a/src/Controller/AdminPages/SupplierController.php b/src/Controller/AdminPages/SupplierController.php
index c28a114d..4cd5e46b 100644
--- a/src/Controller/AdminPages/SupplierController.php
+++ b/src/Controller/AdminPages/SupplierController.php
@@ -35,6 +35,9 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 
+/**
+ * @see \App\Tests\Controller\AdminPages\SupplierControllerTest
+ */
 #[Route(path: '/supplier')]
 class SupplierController extends BaseAdminController
 {
diff --git a/src/Controller/PartListsController.php b/src/Controller/PartListsController.php
index 322d2ebf..83d29ca6 100644
--- a/src/Controller/PartListsController.php
+++ b/src/Controller/PartListsController.php
@@ -97,7 +97,7 @@ class PartListsController extends AbstractController
         $attrs['disabled'] = $disabled;
 
         $parent = $form->getParent();
-        if (!$parent instanceof \Symfony\Component\Form\FormInterface) {
+        if (!$parent instanceof FormInterface) {
             throw new \RuntimeException('This function can only be used on form fields that are children of another form!');
         }
 
diff --git a/src/Controller/RedirectController.php b/src/Controller/RedirectController.php
index 16bed9ea..aef346d9 100644
--- a/src/Controller/RedirectController.php
+++ b/src/Controller/RedirectController.php
@@ -30,6 +30,9 @@ use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
+/**
+ * @see \App\Tests\Controller\RedirectControllerTest
+ */
 class RedirectController extends AbstractController
 {
     public function __construct(protected string $default_locale, protected TranslatorInterface $translator, protected bool $enforce_index_php)
@@ -55,7 +58,7 @@ class RedirectController extends AbstractController
 
         //If either mod_rewrite is not enabled or the index.php version is enforced, add index.php to the string
         if (($this->enforce_index_php || !$this->checkIfModRewriteAvailable())
-            && !str_contains($new_url, 'index.php')) {
+            && !str_contains((string) $new_url, 'index.php')) {
             //Like Request::getUriForPath only with index.php
             $new_url = $request->getSchemeAndHttpHost().$request->getBaseUrl().'/index.php/'.$locale.$request->getPathInfo();
         }
diff --git a/src/Entity/Attachments/Attachment.php b/src/Entity/Attachments/Attachment.php
index f2c6253e..ae701ccd 100644
--- a/src/Entity/Attachments/Attachment.php
+++ b/src/Entity/Attachments/Attachment.php
@@ -36,6 +36,7 @@ use LogicException;
 
 /**
  * Class Attachment.
+ * @see \App\Tests\Entity\Attachments\AttachmentTest
  */
 #[ORM\Entity(repositoryClass: AttachmentRepository::class)]
 #[ORM\InheritanceType('SINGLE_TABLE')]
diff --git a/src/Entity/Attachments/AttachmentType.php b/src/Entity/Attachments/AttachmentType.php
index ed59a2da..9bff255a 100644
--- a/src/Entity/Attachments/AttachmentType.php
+++ b/src/Entity/Attachments/AttachmentType.php
@@ -34,6 +34,7 @@ use Symfony\Component\Validator\Constraints as Assert;
 
 /**
  * Class AttachmentType.
+ * @see \App\Tests\Entity\Attachments\AttachmentTypeTest
  */
 #[ORM\Entity(repositoryClass: StructuralDBElementRepository::class)]
 #[ORM\Table(name: '`attachment_types`')]
diff --git a/src/Entity/Base/AbstractStructuralDBElement.php b/src/Entity/Base/AbstractStructuralDBElement.php
index a1dc80dd..6e82a47d 100644
--- a/src/Entity/Base/AbstractStructuralDBElement.php
+++ b/src/Entity/Base/AbstractStructuralDBElement.php
@@ -47,6 +47,7 @@ use Symfony\Component\Serializer\Annotation\Groups;
  * an attribute of a root element, you will get an exception!
  *
  *
+ * @see \App\Tests\Entity\Base\AbstractStructuralDBElementTest
  */
 #[UniqueEntity(fields: ['name', 'parent'], ignoreNull: false, message: 'structural.entity.unique_name')]
 #[ORM\MappedSuperclass(repositoryClass: StructuralDBElementRepository::class)]
diff --git a/src/Entity/LogSystem/AbstractLogEntry.php b/src/Entity/LogSystem/AbstractLogEntry.php
index 7cc064b7..f6176e4f 100644
--- a/src/Entity/LogSystem/AbstractLogEntry.php
+++ b/src/Entity/LogSystem/AbstractLogEntry.php
@@ -51,6 +51,7 @@ use App\Repository\LogEntryRepository;
 
 /**
  * This entity describes an entry in the event log.
+ * @see \App\Tests\Entity\LogSystem\AbstractLogEntryTest
  */
 #[ORM\Entity(repositoryClass: LogEntryRepository::class)]
 #[ORM\Table('log')]
diff --git a/src/Entity/Parameters/PartParameter.php b/src/Entity/Parameters/PartParameter.php
index 36fc71fb..6c150e6b 100644
--- a/src/Entity/Parameters/PartParameter.php
+++ b/src/Entity/Parameters/PartParameter.php
@@ -47,6 +47,9 @@ use App\Entity\Parts\Part;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 
+/**
+ * @see \App\Tests\Entity\Parameters\PartParameterTest
+ */
 #[UniqueEntity(fields: ['name', 'group', 'element'])]
 #[ORM\Entity(repositoryClass: ParameterRepository::class)]
 class PartParameter extends AbstractParameter
diff --git a/src/Entity/Parts/Part.php b/src/Entity/Parts/Part.php
index b8ff5abb..4fef18f2 100644
--- a/src/Entity/Parts/Part.php
+++ b/src/Entity/Parts/Part.php
@@ -49,6 +49,7 @@ use Symfony\Component\Validator\Context\ExecutionContextInterface;
  *
  * The class properties are split over various traits in directory PartTraits.
  * Otherwise, this class would be too big, to be maintained.
+ * @see \App\Tests\Entity\Parts\PartTest
  */
 #[UniqueEntity(fields: ['ipn'], message: 'part.ipn.must_be_unique')]
 #[ORM\Entity(repositoryClass: PartRepository::class)]
diff --git a/src/Entity/Parts/PartLot.php b/src/Entity/Parts/PartLot.php
index 7bec9b9c..f6a9d404 100644
--- a/src/Entity/Parts/PartLot.php
+++ b/src/Entity/Parts/PartLot.php
@@ -42,6 +42,7 @@ use Symfony\Component\Validator\Context\ExecutionContextInterface;
  * It is the connection between a part and its store locations.
  *
  * @ValidPartLot()
+ * @see \App\Tests\Entity\Parts\PartLotTest
  */
 #[ORM\Entity]
 #[ORM\HasLifecycleCallbacks]
diff --git a/src/Entity/UserSystem/PermissionData.php b/src/Entity/UserSystem/PermissionData.php
index 5c4e84c5..998dfead 100644
--- a/src/Entity/UserSystem/PermissionData.php
+++ b/src/Entity/UserSystem/PermissionData.php
@@ -26,6 +26,7 @@ use Doctrine\ORM\Mapping as ORM;
 /**
  * This class is used to store the permissions of a user.
  * This has to be an embeddable or otherwise doctrine could not track the changes of the underlying data array (which is serialized to JSON in the database)
+ * @see \App\Tests\Entity\UserSystem\PermissionDataTest
  */
 #[ORM\Embeddable]
 final class PermissionData implements \JsonSerializable
diff --git a/src/Entity/UserSystem/User.php b/src/Entity/UserSystem/User.php
index c1cd9a26..98665781 100644
--- a/src/Entity/UserSystem/User.php
+++ b/src/Entity/UserSystem/User.php
@@ -57,6 +57,7 @@ use Jbtronics\TFAWebauthn\Model\TwoFactorInterface as WebauthnTwoFactorInterface
 /**
  * This entity represents a user, which can log in and have permissions.
  * Also, this entity is able to save some information about the user, like the names, email-address and other info.
+ * @see \App\Tests\Entity\UserSystem\UserTest
  */
 #[UniqueEntity('name', message: 'validator.user.username_already_used')]
 #[ORM\Entity(repositoryClass: UserRepository::class)]
diff --git a/src/Helpers/BBCodeToMarkdownConverter.php b/src/Helpers/BBCodeToMarkdownConverter.php
index f800006b..922e6a7e 100644
--- a/src/Helpers/BBCodeToMarkdownConverter.php
+++ b/src/Helpers/BBCodeToMarkdownConverter.php
@@ -25,6 +25,9 @@ namespace App\Helpers;
 use League\HTMLToMarkdown\HtmlConverter;
 use s9e\TextFormatter\Bundles\Forum as TextFormatter;
 
+/**
+ * @see \App\Tests\Helpers\BBCodeToMarkdownConverterTest
+ */
 class BBCodeToMarkdownConverter
 {
     protected HtmlConverter $html_to_markdown;
diff --git a/src/Helpers/Projects/ProjectBuildRequest.php b/src/Helpers/Projects/ProjectBuildRequest.php
index f231c50f..29b5f14f 100644
--- a/src/Helpers/Projects/ProjectBuildRequest.php
+++ b/src/Helpers/Projects/ProjectBuildRequest.php
@@ -28,6 +28,7 @@ use App\Validator\Constraints\ProjectSystem\ValidProjectBuildRequest;
 
 /**
  * @ValidProjectBuildRequest()
+ * @see \App\Tests\Helpers\Projects\ProjectBuildRequestTest
  */
 final class ProjectBuildRequest
 {
diff --git a/src/Repository/NamedDBElementRepository.php b/src/Repository/NamedDBElementRepository.php
index 8485d50a..2168d92d 100644
--- a/src/Repository/NamedDBElementRepository.php
+++ b/src/Repository/NamedDBElementRepository.php
@@ -26,6 +26,9 @@ use App\Entity\Base\AbstractNamedDBElement;
 use App\Entity\UserSystem\User;
 use App\Helpers\Trees\TreeViewNode;
 
+/**
+ * @see \App\Tests\Repository\NamedDBElementRepositoryTest
+ */
 class NamedDBElementRepository extends DBElementRepository
 {
     /**
diff --git a/src/Repository/StructuralDBElementRepository.php b/src/Repository/StructuralDBElementRepository.php
index 19143def..0f2dcdea 100644
--- a/src/Repository/StructuralDBElementRepository.php
+++ b/src/Repository/StructuralDBElementRepository.php
@@ -27,6 +27,9 @@ use App\Helpers\Trees\StructuralDBElementIterator;
 use App\Helpers\Trees\TreeViewNode;
 use RecursiveIteratorIterator;
 
+/**
+ * @see \App\Tests\Repository\StructuralDBElementRepositoryTest
+ */
 class StructuralDBElementRepository extends NamedDBElementRepository
 {
     /**
diff --git a/src/Security/EnsureSAMLUserForSAMLLoginChecker.php b/src/Security/EnsureSAMLUserForSAMLLoginChecker.php
index 0d80630d..674d7e26 100644
--- a/src/Security/EnsureSAMLUserForSAMLLoginChecker.php
+++ b/src/Security/EnsureSAMLUserForSAMLLoginChecker.php
@@ -27,6 +27,9 @@ use Symfony\Component\Security\Core\Event\AuthenticationSuccessEvent;
 use Symfony\Component\Security\Core\Exception\CustomUserMessageAccountStatusException;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
+/**
+ * @see \App\Tests\Security\EnsureSAMLUserForSAMLLoginCheckerTest
+ */
 class EnsureSAMLUserForSAMLLoginChecker implements EventSubscriberInterface
 {
     public function __construct(private readonly TranslatorInterface $translator)
diff --git a/src/Security/SamlUserFactory.php b/src/Security/SamlUserFactory.php
index 4bfefc88..924e4e5e 100644
--- a/src/Security/SamlUserFactory.php
+++ b/src/Security/SamlUserFactory.php
@@ -29,6 +29,9 @@ use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Security\Core\Event\AuthenticationSuccessEvent;
 use Symfony\Component\Security\Core\User\UserInterface;
 
+/**
+ * @see \App\Tests\Security\SamlUserFactoryTest
+ */
 class SamlUserFactory implements SamlUserFactoryInterface, EventSubscriberInterface
 {
     private readonly array $saml_role_mapping;
diff --git a/src/Security/UserChecker.php b/src/Security/UserChecker.php
index 55fa3db3..fd53a295 100644
--- a/src/Security/UserChecker.php
+++ b/src/Security/UserChecker.php
@@ -29,6 +29,9 @@ use Symfony\Component\Security\Core\User\UserCheckerInterface;
 use Symfony\Component\Security\Core\User\UserInterface;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
+/**
+ * @see \App\Tests\Security\UserCheckerTest
+ */
 final class UserChecker implements UserCheckerInterface
 {
     public function __construct(private readonly TranslatorInterface $translator)
diff --git a/src/Serializer/BigNumberNormalizer.php b/src/Serializer/BigNumberNormalizer.php
index 89826962..49477725 100644
--- a/src/Serializer/BigNumberNormalizer.php
+++ b/src/Serializer/BigNumberNormalizer.php
@@ -24,6 +24,9 @@ use Brick\Math\BigNumber;
 use Symfony\Component\Serializer\Normalizer\CacheableSupportsMethodInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
+/**
+ * @see \App\Tests\Serializer\BigNumberNormalizerTest
+ */
 class BigNumberNormalizer implements NormalizerInterface, CacheableSupportsMethodInterface
 {
 
diff --git a/src/Serializer/PartNormalizer.php b/src/Serializer/PartNormalizer.php
index 740d9861..58158cfe 100644
--- a/src/Serializer/PartNormalizer.php
+++ b/src/Serializer/PartNormalizer.php
@@ -32,6 +32,9 @@ use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 
+/**
+ * @see \App\Tests\Serializer\PartNormalizerTest
+ */
 class PartNormalizer implements NormalizerInterface, DenormalizerInterface, CacheableSupportsMethodInterface
 {
     private const DENORMALIZE_KEY_MAPPING = [
diff --git a/src/Serializer/StructuralElementDenormalizer.php b/src/Serializer/StructuralElementDenormalizer.php
index 8de72fde..4212fd5d 100644
--- a/src/Serializer/StructuralElementDenormalizer.php
+++ b/src/Serializer/StructuralElementDenormalizer.php
@@ -27,6 +27,9 @@ use Symfony\Component\Serializer\Normalizer\CacheableSupportsMethodInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 
+/**
+ * @see \App\Tests\Serializer\StructuralElementDenormalizerTest
+ */
 class StructuralElementDenormalizer implements DenormalizerInterface, CacheableSupportsMethodInterface
 {
 
diff --git a/src/Serializer/StructuralElementFromNameDenormalizer.php b/src/Serializer/StructuralElementFromNameDenormalizer.php
index 9de31048..662e3afa 100644
--- a/src/Serializer/StructuralElementFromNameDenormalizer.php
+++ b/src/Serializer/StructuralElementFromNameDenormalizer.php
@@ -26,6 +26,9 @@ use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Component\Serializer\Normalizer\CacheableSupportsMethodInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 
+/**
+ * @see \App\Tests\Serializer\StructuralElementFromNameDenormalizerTest
+ */
 class StructuralElementFromNameDenormalizer implements DenormalizerInterface, CacheableSupportsMethodInterface
 {
     public function __construct(private readonly EntityManagerInterface $em)
diff --git a/src/Serializer/StructuralElementNormalizer.php b/src/Serializer/StructuralElementNormalizer.php
index fb6a42b1..aeae9aae 100644
--- a/src/Serializer/StructuralElementNormalizer.php
+++ b/src/Serializer/StructuralElementNormalizer.php
@@ -25,6 +25,9 @@ use Symfony\Component\Serializer\Normalizer\CacheableSupportsMethodInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 
+/**
+ * @see \App\Tests\Serializer\StructuralElementNormalizerTest
+ */
 class StructuralElementNormalizer implements NormalizerInterface, CacheableSupportsMethodInterface
 {
     public function __construct(private readonly ObjectNormalizer $normalizer)
diff --git a/src/Services/Attachments/AttachmentPathResolver.php b/src/Services/Attachments/AttachmentPathResolver.php
index 116072b5..0628a6a9 100644
--- a/src/Services/Attachments/AttachmentPathResolver.php
+++ b/src/Services/Attachments/AttachmentPathResolver.php
@@ -29,6 +29,7 @@ use Symfony\Component\Filesystem\Filesystem;
 /**
  * This service converts the relative pathes for attachments saved in database (like %MEDIA%/img.jpg) to real pathes
  * an vice versa.
+ * @see \App\Tests\Services\Attachments\AttachmentPathResolverTest
  */
 class AttachmentPathResolver
 {
diff --git a/src/Services/Attachments/AttachmentURLGenerator.php b/src/Services/Attachments/AttachmentURLGenerator.php
index c2a3b433..0efbf1e6 100644
--- a/src/Services/Attachments/AttachmentURLGenerator.php
+++ b/src/Services/Attachments/AttachmentURLGenerator.php
@@ -31,6 +31,9 @@ use function strlen;
 use Symfony\Component\Asset\Packages;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
+/**
+ * @see \App\Tests\Services\Attachments\AttachmentURLGeneratorTest
+ */
 class AttachmentURLGenerator
 {
     protected string $public_path;
diff --git a/src/Services/Attachments/BuiltinAttachmentsFinder.php b/src/Services/Attachments/BuiltinAttachmentsFinder.php
index f3f8740f..21be0730 100644
--- a/src/Services/Attachments/BuiltinAttachmentsFinder.php
+++ b/src/Services/Attachments/BuiltinAttachmentsFinder.php
@@ -30,6 +30,7 @@ use Symfony\Contracts\Cache\CacheInterface;
 
 /**
  * This service is used to find builtin attachment ressources.
+ * @see \App\Tests\Services\Attachments\BuiltinAttachmentsFinderTest
  */
 class BuiltinAttachmentsFinder
 {
@@ -57,7 +58,7 @@ class BuiltinAttachmentsFinder
         foreach($finder as $file) {
             $folder = $file->getRelativePath();
             //Normalize path (replace \ with /)
-            $folder = str_replace('\\', '/', $folder);
+            $folder = str_replace('\\', '/', (string) $folder);
 
             if(!isset($output[$folder])) {
                 $output[$folder] = [];
diff --git a/src/Services/Attachments/FileTypeFilterTools.php b/src/Services/Attachments/FileTypeFilterTools.php
index 948b429b..c7ef3ab1 100644
--- a/src/Services/Attachments/FileTypeFilterTools.php
+++ b/src/Services/Attachments/FileTypeFilterTools.php
@@ -32,6 +32,7 @@ use Symfony\Contracts\Cache\ItemInterface;
  * A service that helps to work with filetype filters (based on the format <input type=file> accept uses).
  * See https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file#Unique_file_type_specifiers for
  * more details.
+ * @see \App\Tests\Services\Attachments\FileTypeFilterToolsTest
  */
 class FileTypeFilterTools
 {
diff --git a/src/Services/ElementTypeNameGenerator.php b/src/Services/ElementTypeNameGenerator.php
index dc8c94a6..2fb81c1b 100644
--- a/src/Services/ElementTypeNameGenerator.php
+++ b/src/Services/ElementTypeNameGenerator.php
@@ -49,6 +49,9 @@ use Doctrine\ORM\Mapping\Entity;
 use function get_class;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
+/**
+ * @see \App\Tests\Services\ElementTypeNameGeneratorTest
+ */
 class ElementTypeNameGenerator
 {
     protected array $mapping;
@@ -127,7 +130,7 @@ class ElementTypeNameGenerator
     {
         $type = $this->getLocalizedTypeLabel($entity);
         if ($use_html) {
-            return '<i>'.$type.':</i> '.htmlspecialchars($entity->getName());
+            return '<i>'.$type.':</i> '.htmlspecialchars((string) $entity->getName());
         }
 
         return $type.': '.$entity->getName();
diff --git a/src/Services/Formatters/AmountFormatter.php b/src/Services/Formatters/AmountFormatter.php
index d092f2cd..73d59113 100644
--- a/src/Services/Formatters/AmountFormatter.php
+++ b/src/Services/Formatters/AmountFormatter.php
@@ -29,6 +29,7 @@ use Symfony\Component\OptionsResolver\OptionsResolver;
 
 /**
  * This service formats a part amount using a Measurement Unit.
+ * @see \App\Tests\Services\Formatters\AmountFormatterTest
  */
 class AmountFormatter
 {
diff --git a/src/Services/Formatters/SIFormatter.php b/src/Services/Formatters/SIFormatter.php
index a6d69d0b..a6325987 100644
--- a/src/Services/Formatters/SIFormatter.php
+++ b/src/Services/Formatters/SIFormatter.php
@@ -24,6 +24,7 @@ namespace App\Services\Formatters;
 
 /**
  * A service that helps you to format values using the SI prefixes.
+ * @see \App\Tests\Services\Formatters\SIFormatterTest
  */
 class SIFormatter
 {
diff --git a/src/Services/ImportExportSystem/BOMImporter.php b/src/Services/ImportExportSystem/BOMImporter.php
index 72103436..7227c419 100644
--- a/src/Services/ImportExportSystem/BOMImporter.php
+++ b/src/Services/ImportExportSystem/BOMImporter.php
@@ -27,6 +27,9 @@ use League\Csv\Reader;
 use Symfony\Component\HttpFoundation\File\File;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 
+/**
+ * @see \App\Tests\Services\ImportExportSystem\BOMImporterTest
+ */
 class BOMImporter
 {
 
diff --git a/src/Services/ImportExportSystem/EntityExporter.php b/src/Services/ImportExportSystem/EntityExporter.php
index 89b0e946..50b6b7cc 100644
--- a/src/Services/ImportExportSystem/EntityExporter.php
+++ b/src/Services/ImportExportSystem/EntityExporter.php
@@ -36,6 +36,7 @@ use function Symfony\Component\String\u;
 
 /**
  * Use this class to export an entity to multiple file formats.
+ * @see \App\Tests\Services\ImportExportSystem\EntityExporterTest
  */
 class EntityExporter
 {
diff --git a/src/Services/ImportExportSystem/EntityImporter.php b/src/Services/ImportExportSystem/EntityImporter.php
index 60d064f3..1aa50db5 100644
--- a/src/Services/ImportExportSystem/EntityImporter.php
+++ b/src/Services/ImportExportSystem/EntityImporter.php
@@ -36,6 +36,9 @@ use Symfony\Component\OptionsResolver\OptionsResolver;
 use Symfony\Component\Serializer\SerializerInterface;
 use Symfony\Component\Validator\Validator\ValidatorInterface;
 
+/**
+ * @see \App\Tests\Services\ImportExportSystem\EntityImporterTest
+ */
 class EntityImporter
 {
     public function __construct(protected SerializerInterface $serializer, protected EntityManagerInterface $em, protected ValidatorInterface $validator)
diff --git a/src/Services/LabelSystem/BarcodeGenerator.php b/src/Services/LabelSystem/BarcodeGenerator.php
index 90cbc5d7..b8ab099e 100644
--- a/src/Services/LabelSystem/BarcodeGenerator.php
+++ b/src/Services/LabelSystem/BarcodeGenerator.php
@@ -48,6 +48,9 @@ use App\Services\LabelSystem\Barcodes\BarcodeContentGenerator;
 use Com\Tecnick\Barcode\Barcode;
 use InvalidArgumentException;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\BarcodeGeneratorTest
+ */
 final class BarcodeGenerator
 {
     public function __construct(private readonly BarcodeContentGenerator $barcodeContentGenerator)
diff --git a/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php b/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
index 6930bd79..5acf98f1 100644
--- a/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
@@ -48,6 +48,9 @@ use App\Entity\Parts\Storelocation;
 use InvalidArgumentException;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\Barcodes\BarcodeContentGeneratorTest
+ */
 final class BarcodeContentGenerator
 {
     public const PREFIX_MAP = [
diff --git a/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php b/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
index 4e6d8cbd..a5b6cb5e 100644
--- a/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
@@ -43,6 +43,9 @@ namespace App\Services\LabelSystem\Barcodes;
 
 use InvalidArgumentException;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\Barcodes\BarcodeNormalizerTest
+ */
 final class BarcodeNormalizer
 {
     private const PREFIX_TYPE_MAP = [
diff --git a/src/Services/LabelSystem/Barcodes/BarcodeRedirector.php b/src/Services/LabelSystem/Barcodes/BarcodeRedirector.php
index ba425483..0eba0ed4 100644
--- a/src/Services/LabelSystem/Barcodes/BarcodeRedirector.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeRedirector.php
@@ -47,6 +47,9 @@ use Doctrine\ORM\EntityNotFoundException;
 use InvalidArgumentException;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\Barcodes\BarcodeRedirectorTest
+ */
 final class BarcodeRedirector
 {
     public function __construct(private readonly UrlGeneratorInterface $urlGenerator, private readonly EntityManagerInterface $em)
diff --git a/src/Services/LabelSystem/LabelGenerator.php b/src/Services/LabelSystem/LabelGenerator.php
index d5ae2718..9f5d666b 100644
--- a/src/Services/LabelSystem/LabelGenerator.php
+++ b/src/Services/LabelSystem/LabelGenerator.php
@@ -48,6 +48,9 @@ use App\Entity\Parts\Storelocation;
 use Dompdf\Dompdf;
 use InvalidArgumentException;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\LabelGeneratorTest
+ */
 final class LabelGenerator
 {
     public const CLASS_SUPPORT_MAPPING = [
diff --git a/src/Services/LabelSystem/LabelTextReplacer.php b/src/Services/LabelSystem/LabelTextReplacer.php
index 3c0b5f92..e352729c 100644
--- a/src/Services/LabelSystem/LabelTextReplacer.php
+++ b/src/Services/LabelSystem/LabelTextReplacer.php
@@ -46,6 +46,7 @@ use App\Services\LabelSystem\PlaceholderProviders\PlaceholderProviderInterface;
 /**
  * This service replaces the Placeholders of the user provided lines with the proper informations.
  * It uses the PlaceholderProviders provided by PlaceholderProviderInterface classes.
+ * @see \App\Tests\Services\LabelSystem\LabelTextReplacerTest
  */
 final class LabelTextReplacer
 {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php b/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
index 1678bda1..5a9b2294 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
@@ -50,6 +50,7 @@ use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
 /**
  * Provides Placeholders for infos about global infos like Installation name or datetimes.
+ * @see \App\Tests\Services\LabelSystem\PlaceholderProviders\GlobalProvidersTest
  */
 final class GlobalProviders implements PlaceholderProviderInterface
 {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
index fc5fedfe..d8d38120 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
@@ -43,6 +43,9 @@ namespace App\Services\LabelSystem\PlaceholderProviders;
 
 use App\Entity\Contracts\NamedElementInterface;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\PlaceholderProviders\NamedElementProviderTest
+ */
 final class NamedElementProvider implements PlaceholderProviderInterface
 {
     public function replace(string $placeholder, object $label_target, array $options = []): ?string
diff --git a/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php b/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
index f7ff0b45..fb9447ba 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
@@ -49,6 +49,9 @@ use App\Services\LabelSystem\LabelTextReplacer;
 use IntlDateFormatter;
 use Locale;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\PlaceholderProviders\PartLotProviderTest
+ */
 final class PartLotProvider implements PlaceholderProviderInterface
 {
     public function __construct(private readonly LabelTextReplacer $labelTextReplacer, private readonly AmountFormatter $amountFormatter)
diff --git a/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php b/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
index dbbe6263..4174c623 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
@@ -49,6 +49,9 @@ use App\Services\Formatters\SIFormatter;
 use Parsedown;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\PlaceholderProviders\PartProviderTest
+ */
 final class PartProvider implements PlaceholderProviderInterface
 {
     public function __construct(private readonly SIFormatter $siFormatter, private readonly TranslatorInterface $translator)
diff --git a/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
index ef5967b2..8588e133 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
@@ -46,6 +46,9 @@ use DateTime;
 use IntlDateFormatter;
 use Locale;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\PlaceholderProviders\TimestampableElementProviderTest
+ */
 final class TimestampableElementProvider implements PlaceholderProviderInterface
 {
     public function replace(string $placeholder, object $label_target, array $options = []): ?string
diff --git a/src/Services/LabelSystem/SandboxedTwigProvider.php b/src/Services/LabelSystem/SandboxedTwigProvider.php
index 39b47bfb..6c1bbce1 100644
--- a/src/Services/LabelSystem/SandboxedTwigProvider.php
+++ b/src/Services/LabelSystem/SandboxedTwigProvider.php
@@ -68,6 +68,9 @@ use Twig\Extra\Intl\IntlExtension;
 use Twig\Loader\ArrayLoader;
 use Twig\Sandbox\SecurityPolicyInterface;
 
+/**
+ * @see \App\Tests\Services\LabelSystem\SandboxedTwigProviderTest
+ */
 final class SandboxedTwigProvider
 {
     private const ALLOWED_TAGS = ['apply', 'autoescape', 'do', 'for', 'if', 'set', 'verbatim', 'with'];
diff --git a/src/Services/LogSystem/EventCommentHelper.php b/src/Services/LogSystem/EventCommentHelper.php
index cf06b724..45e95b2c 100644
--- a/src/Services/LogSystem/EventCommentHelper.php
+++ b/src/Services/LogSystem/EventCommentHelper.php
@@ -41,6 +41,9 @@ declare(strict_types=1);
 
 namespace App\Services\LogSystem;
 
+/**
+ * @see \App\Tests\Services\LogSystem\EventCommentHelperTest
+ */
 class EventCommentHelper
 {
     protected const MAX_MESSAGE_LENGTH = 255;
diff --git a/src/Services/LogSystem/EventCommentNeededHelper.php b/src/Services/LogSystem/EventCommentNeededHelper.php
index 23e22072..3738b330 100644
--- a/src/Services/LogSystem/EventCommentNeededHelper.php
+++ b/src/Services/LogSystem/EventCommentNeededHelper.php
@@ -23,6 +23,7 @@ namespace App\Services\LogSystem;
 /**
  * This service is used to check if a log change comment is needed for a given operation type.
  * It is configured using the "enforce_change_comments_for" config parameter.
+ * @see \App\Tests\Services\LogSystem\EventCommentNeededHelperTest
  */
 class EventCommentNeededHelper
 {
diff --git a/src/Services/LogSystem/EventLogger.php b/src/Services/LogSystem/EventLogger.php
index 82e2df3a..909c5ab2 100644
--- a/src/Services/LogSystem/EventLogger.php
+++ b/src/Services/LogSystem/EventLogger.php
@@ -29,6 +29,9 @@ use App\Entity\UserSystem\User;
 use App\Services\Misc\ConsoleInfoHelper;
 use Doctrine\ORM\EntityManagerInterface;
 
+/**
+ * @see \App\Tests\Services\LogSystem\EventLoggerTest
+ */
 class EventLogger
 {
     public function __construct(protected int $minimum_log_level, protected array $blacklist, protected array $whitelist, protected EntityManagerInterface $em, protected Security $security, protected ConsoleInfoHelper $console_info_helper)
diff --git a/src/Services/Misc/FAIconGenerator.php b/src/Services/Misc/FAIconGenerator.php
index b8ee4481..997e9f39 100644
--- a/src/Services/Misc/FAIconGenerator.php
+++ b/src/Services/Misc/FAIconGenerator.php
@@ -26,6 +26,9 @@ use App\Entity\Attachments\Attachment;
 use function in_array;
 use InvalidArgumentException;
 
+/**
+ * @see \App\Tests\Services\Misc\FAIconGeneratorTest
+ */
 class FAIconGenerator
 {
     protected const EXT_MAPPING = [
diff --git a/src/Services/Misc/RangeParser.php b/src/Services/Misc/RangeParser.php
index ddd4fd3b..2ff98477 100644
--- a/src/Services/Misc/RangeParser.php
+++ b/src/Services/Misc/RangeParser.php
@@ -45,6 +45,7 @@ use InvalidArgumentException;
 
 /**
  * This Parser allows to parse number ranges like 1-3, 4, 5.
+ * @see \App\Tests\Services\Misc\RangeParserTest
  */
 class RangeParser
 {
diff --git a/src/Services/Parameters/ParameterExtractor.php b/src/Services/Parameters/ParameterExtractor.php
index 3257d96d..077101c8 100644
--- a/src/Services/Parameters/ParameterExtractor.php
+++ b/src/Services/Parameters/ParameterExtractor.php
@@ -47,6 +47,9 @@ use InvalidArgumentException;
 
 use function preg_match;
 
+/**
+ * @see \App\Tests\Services\Parameters\ParameterExtractorTest
+ */
 class ParameterExtractor
 {
     protected const ALLOWED_PARAM_SEPARATORS = [', ', "\n"];
diff --git a/src/Services/Parts/PartLotWithdrawAddHelper.php b/src/Services/Parts/PartLotWithdrawAddHelper.php
index 9ffbbbe9..07f4bc04 100644
--- a/src/Services/Parts/PartLotWithdrawAddHelper.php
+++ b/src/Services/Parts/PartLotWithdrawAddHelper.php
@@ -8,6 +8,9 @@ use App\Entity\Parts\PartLot;
 use App\Services\LogSystem\EventCommentHelper;
 use App\Services\LogSystem\EventLogger;
 
+/**
+ * @see \App\Tests\Services\Parts\PartLotWithdrawAddHelperTest
+ */
 final class PartLotWithdrawAddHelper
 {
     public function __construct(private readonly EventLogger $eventLogger, private readonly EventCommentHelper $eventCommentHelper)
diff --git a/src/Services/Parts/PricedetailHelper.php b/src/Services/Parts/PricedetailHelper.php
index d989593d..092cc278 100644
--- a/src/Services/Parts/PricedetailHelper.php
+++ b/src/Services/Parts/PricedetailHelper.php
@@ -32,6 +32,9 @@ use Locale;
 
 use function count;
 
+/**
+ * @see \App\Tests\Services\Parts\PricedetailHelperTest
+ */
 class PricedetailHelper
 {
     protected string $locale;
@@ -54,7 +57,7 @@ class PricedetailHelper
         foreach ($orderdetails as $orderdetail) {
             $pricedetails = $orderdetail->getPricedetails();
             //The orderdetail must have pricedetails, otherwise this will not work!
-            if (0 === count($pricedetails)) {
+            if (0 === (is_countable($pricedetails) ? count($pricedetails) : 0)) {
                 continue;
             }
 
@@ -99,7 +102,7 @@ class PricedetailHelper
         foreach ($orderdetails as $orderdetail) {
             $pricedetails = $orderdetail->getPricedetails();
             //The orderdetail must have pricedetails, otherwise this will not work!
-            if (0 === count($pricedetails)) {
+            if (0 === (is_countable($pricedetails) ? count($pricedetails) : 0)) {
                 continue;
             }
 
diff --git a/src/Services/ProjectSystem/ProjectBuildHelper.php b/src/Services/ProjectSystem/ProjectBuildHelper.php
index 1ca2d0e8..b9ffc374 100644
--- a/src/Services/ProjectSystem/ProjectBuildHelper.php
+++ b/src/Services/ProjectSystem/ProjectBuildHelper.php
@@ -26,6 +26,9 @@ use App\Entity\ProjectSystem\ProjectBOMEntry;
 use App\Helpers\Projects\ProjectBuildRequest;
 use App\Services\Parts\PartLotWithdrawAddHelper;
 
+/**
+ * @see \App\Tests\Services\ProjectSystem\ProjectBuildHelperTest
+ */
 class ProjectBuildHelper
 {
     public function __construct(private readonly PartLotWithdrawAddHelper $withdraw_add_helper)
diff --git a/src/Services/ProjectSystem/ProjectBuildPartHelper.php b/src/Services/ProjectSystem/ProjectBuildPartHelper.php
index 80ab9395..446f5f55 100644
--- a/src/Services/ProjectSystem/ProjectBuildPartHelper.php
+++ b/src/Services/ProjectSystem/ProjectBuildPartHelper.php
@@ -5,6 +5,9 @@ namespace App\Services\ProjectSystem;
 use App\Entity\Parts\Part;
 use App\Entity\ProjectSystem\Project;
 
+/**
+ * @see \App\Tests\Services\ProjectSystem\ProjectBuildPartHelperTest
+ */
 class ProjectBuildPartHelper
 {
     /**
diff --git a/src/Services/Trees/NodesListBuilder.php b/src/Services/Trees/NodesListBuilder.php
index 0196b215..49c0aa6b 100644
--- a/src/Services/Trees/NodesListBuilder.php
+++ b/src/Services/Trees/NodesListBuilder.php
@@ -31,6 +31,7 @@ use Symfony\Contracts\Cache\TagAwareCacheInterface;
 
 /**
  *  This service gives you a flat list containing all structured entities in the order of the structure.
+ * @see \App\Tests\Services\Trees\NodesListBuilderTest
  */
 class NodesListBuilder
 {
diff --git a/src/Services/Trees/TreeViewGenerator.php b/src/Services/Trees/TreeViewGenerator.php
index 1ee0647b..dd2db178 100644
--- a/src/Services/Trees/TreeViewGenerator.php
+++ b/src/Services/Trees/TreeViewGenerator.php
@@ -45,6 +45,9 @@ use Symfony\Contracts\Translation\TranslatorInterface;
 
 use function count;
 
+/**
+ * @see \App\Tests\Services\Trees\TreeViewGeneratorTest
+ */
 class TreeViewGenerator
 {
     public function __construct(protected EntityURLGenerator $urlGenerator, protected EntityManagerInterface $em, protected TagAwareCacheInterface $cache, protected UserCacheKeyGenerator $keyGenerator, protected TranslatorInterface $translator, protected bool $rootNodeExpandedByDefault, protected bool $rootNodeEnabled)
@@ -130,43 +133,29 @@ class TreeViewGenerator
 
     protected function entityClassToRootNodeString(string $class): string
     {
-        switch ($class) {
-            case Category::class:
-                return $this->translator->trans('category.labelp');
-            case Storelocation::class:
-                return $this->translator->trans('storelocation.labelp');
-            case Footprint::class:
-                return $this->translator->trans('footprint.labelp');
-            case Manufacturer::class:
-                return $this->translator->trans('manufacturer.labelp');
-            case Supplier::class:
-                return $this->translator->trans('supplier.labelp');
-            case Project::class:
-                return $this->translator->trans('project.labelp');
-            default:
-                return $this->translator->trans('tree.root_node.text');
-        }
+        return match ($class) {
+            Category::class => $this->translator->trans('category.labelp'),
+            Storelocation::class => $this->translator->trans('storelocation.labelp'),
+            Footprint::class => $this->translator->trans('footprint.labelp'),
+            Manufacturer::class => $this->translator->trans('manufacturer.labelp'),
+            Supplier::class => $this->translator->trans('supplier.labelp'),
+            Project::class => $this->translator->trans('project.labelp'),
+            default => $this->translator->trans('tree.root_node.text'),
+        };
     }
 
     protected function entityClassToRootNodeIcon(string $class): ?string
     {
         $icon = "fa-fw fa-treeview fa-solid ";
-        switch ($class) {
-            case Category::class:
-                return $icon . 'fa-tags';
-            case Storelocation::class:
-                return $icon . 'fa-cube';
-            case Footprint::class:
-                return $icon . 'fa-microchip';
-            case Manufacturer::class:
-                return $icon . 'fa-industry';
-            case Supplier::class:
-                return $icon . 'fa-truck';
-            case Project::class:
-                return $icon . 'fa-archive';
-            default:
-                return null;
-        }
+        return match ($class) {
+            Category::class => $icon . 'fa-tags',
+            Storelocation::class => $icon . 'fa-cube',
+            Footprint::class => $icon . 'fa-microchip',
+            Manufacturer::class => $icon . 'fa-industry',
+            Supplier::class => $icon . 'fa-truck',
+            Project::class => $icon . 'fa-archive',
+            default => null,
+        };
     }
 
     /**
diff --git a/src/Services/UserSystem/PermissionManager.php b/src/Services/UserSystem/PermissionManager.php
index ae3764d8..333e6168 100644
--- a/src/Services/UserSystem/PermissionManager.php
+++ b/src/Services/UserSystem/PermissionManager.php
@@ -37,6 +37,7 @@ use Symfony\Component\Yaml\Yaml;
  * This class manages the permissions of users and groups.
  * Permissions are defined in the config/permissions.yaml file, and are parsed and resolved by this class using the
  * user and hierachical group PermissionData information.
+ * @see \App\Tests\Services\UserSystem\PermissionManagerTest
  */
 class PermissionManager
 {
diff --git a/src/Services/UserSystem/PermissionSchemaUpdater.php b/src/Services/UserSystem/PermissionSchemaUpdater.php
index 3c12d042..b939fa86 100644
--- a/src/Services/UserSystem/PermissionSchemaUpdater.php
+++ b/src/Services/UserSystem/PermissionSchemaUpdater.php
@@ -25,6 +25,9 @@ use App\Entity\UserSystem\PermissionData;
 use App\Entity\UserSystem\User;
 use App\Security\Interfaces\HasPermissionsInterface;
 
+/**
+ * @see \App\Tests\Services\UserSystem\PermissionSchemaUpdaterTest
+ */
 class PermissionSchemaUpdater
 {
     /**
diff --git a/src/Services/UserSystem/TFA/BackupCodeGenerator.php b/src/Services/UserSystem/TFA/BackupCodeGenerator.php
index 9beddf39..a13b9804 100644
--- a/src/Services/UserSystem/TFA/BackupCodeGenerator.php
+++ b/src/Services/UserSystem/TFA/BackupCodeGenerator.php
@@ -27,6 +27,7 @@ use RuntimeException;
 
 /**
  * This class generates random backup codes for two-factor authentication.
+ * @see \App\Tests\Services\UserSystem\TFA\BackupCodeGeneratorTest
  */
 class BackupCodeGenerator
 {
diff --git a/src/Services/UserSystem/TFA/BackupCodeManager.php b/src/Services/UserSystem/TFA/BackupCodeManager.php
index 1fb572c6..70226946 100644
--- a/src/Services/UserSystem/TFA/BackupCodeManager.php
+++ b/src/Services/UserSystem/TFA/BackupCodeManager.php
@@ -26,6 +26,7 @@ use App\Entity\UserSystem\User;
 
 /**
  * This services offers methods to manage backup codes for two-factor authentication.
+ * @see \App\Tests\Services\UserSystem\TFA\BackupCodeManagerTest
  */
 class BackupCodeManager
 {
diff --git a/src/Twig/EntityExtension.php b/src/Twig/EntityExtension.php
index 393c4040..92d69631 100644
--- a/src/Twig/EntityExtension.php
+++ b/src/Twig/EntityExtension.php
@@ -42,6 +42,9 @@ use Twig\Extension\AbstractExtension;
 use Twig\TwigFunction;
 use Twig\TwigTest;
 
+/**
+ * @see \App\Tests\Twig\EntityExtensionTest
+ */
 final class EntityExtension extends AbstractExtension
 {
     public function __construct(protected EntityURLGenerator $entityURLGenerator, protected TreeViewGenerator $treeBuilder, private readonly ElementTypeNameGenerator $nameGenerator)
diff --git a/src/Twig/TwigCoreExtension.php b/src/Twig/TwigCoreExtension.php
index dc63b2e1..d4b14c83 100644
--- a/src/Twig/TwigCoreExtension.php
+++ b/src/Twig/TwigCoreExtension.php
@@ -27,6 +27,7 @@ use Twig\TwigTest;
 
 /**
  * The functionalities here extend the Twig with some core functions, which are independently of Part-DB.
+ * @see \App\Tests\Twig\TwigCoreExtensionTest
  */
 final class TwigCoreExtension extends AbstractExtension
 {
diff --git a/src/Twig/UserExtension.php b/src/Twig/UserExtension.php
index 012f975c..be5d3c41 100644
--- a/src/Twig/UserExtension.php
+++ b/src/Twig/UserExtension.php
@@ -50,6 +50,9 @@ use Twig\Extension\AbstractExtension;
 use Twig\TwigFilter;
 use Twig\TwigFunction;
 
+/**
+ * @see \App\Tests\Twig\UserExtensionTest
+ */
 final class UserExtension extends AbstractExtension
 {
     private readonly LogEntryRepository $repo;