diff --git a/src/Command/User/UpgradePermissionsSchemaCommand.php b/src/Command/User/UpgradePermissionsSchemaCommand.php
index ae5adfff..77ccb70f 100644
--- a/src/Command/User/UpgradePermissionsSchemaCommand.php
+++ b/src/Command/User/UpgradePermissionsSchemaCommand.php
@@ -91,12 +91,12 @@ final class UpgradePermissionsSchemaCommand extends Command
 
         //List all users and groups that need an update
         $io->section('Groups that need an update:');
-        $io->listing(array_map(function (Group $group) {
+        $io->listing(array_map(static function (Group $group) {
             return $group->getName() . ' (ID: '. $group->getID() .', Current version: ' . $group->getPermissions()->getSchemaVersion() . ')';
         }, $groups_to_upgrade));
 
         $io->section('Users that need an update:');
-        $io->listing(array_map(function (User $user) {
+        $io->listing(array_map(static function (User $user) {
             return $user->getUsername() . ' (ID: '. $user->getID() .', Current version: ' . $user->getPermissions()->getSchemaVersion() . ')';
         }, $users_to_upgrade));
 
diff --git a/src/Command/User/UserEnableCommand.php b/src/Command/User/UserEnableCommand.php
index 39878a91..2b913e26 100644
--- a/src/Command/User/UserEnableCommand.php
+++ b/src/Command/User/UserEnableCommand.php
@@ -87,7 +87,7 @@ class UserEnableCommand extends Command
             $io->note('The following users will be enabled:');
         }
         $io->table(['Username', 'Enabled/Disabled'],
-            array_map(function(User $user) {
+            array_map(static function(User $user) {
             return [$user->getFullName(true), $user->isDisabled() ? 'Disabled' : 'Enabled'];
         }, $users));
 
diff --git a/src/Controller/GroupController.php b/src/Controller/GroupController.php
index 1eb10d76..5aa8a371 100644
--- a/src/Controller/GroupController.php
+++ b/src/Controller/GroupController.php
@@ -74,9 +74,9 @@ class GroupController extends BaseAdminController
 
                 //We need to stop the execution here, or our permissions changes will be overwritten by the form values
                 return $this->redirectToRoute('group_edit', ['id' => $entity->getID()]);
-            } else {
-                $this->addFlash('danger', 'csfr_invalid');
             }
+
+            $this->addFlash('danger', 'csfr_invalid');
         }
 
         return $this->_edit($entity, $request, $em, $timestamp);
diff --git a/src/Controller/LogController.php b/src/Controller/LogController.php
index de5d3c17..3c28fa99 100644
--- a/src/Controller/LogController.php
+++ b/src/Controller/LogController.php
@@ -52,7 +52,7 @@ class LogController extends AbstractController
 {
     protected EntityManagerInterface $entityManager;
     protected TimeTravel $timeTravel;
-    protected DBElementRepository $dbRepository;
+    protected EntityRepository $dbRepository;
 
     public function __construct(EntityManagerInterface $entityManager, TimeTravel $timeTravel)
     {
diff --git a/src/Controller/ProjectController.php b/src/Controller/ProjectController.php
index 5f4390ae..7ab192c5 100644
--- a/src/Controller/ProjectController.php
+++ b/src/Controller/ProjectController.php
@@ -114,9 +114,9 @@ class ProjectController extends AbstractController
                     $request->get('_redirect',
                         $this->generateUrl('project_info', ['id' => $project->getID()]
                         )));
-            } else {
-                $this->addFlash('error', 'project.build.flash.invalid_input');
             }
+
+            $this->addFlash('error', 'project.build.flash.invalid_input');
         }
 
         return $this->renderForm('projects/build/build.html.twig', [
diff --git a/src/Controller/SelectAPIController.php b/src/Controller/SelectAPIController.php
index 1b7784e4..49689416 100644
--- a/src/Controller/SelectAPIController.php
+++ b/src/Controller/SelectAPIController.php
@@ -106,7 +106,7 @@ class SelectAPIController extends AbstractController
             3 => $this->translator->trans('export.level.full'),
         ];
 
-        return $this->json(array_map(function ($key, $value) {
+        return $this->json(array_map(static function ($key, $value) {
             return [
                 'text' => $value,
                 'value' => $key,
@@ -198,7 +198,7 @@ class SelectAPIController extends AbstractController
                 ]);
                 //Remove the data-* prefix for each key
                 $data = array_combine(
-                    array_map(function ($key) {
+                    array_map(static function ($key) {
                         if (strpos($key, 'data-') === 0) {
                             return substr($key, 5);
                         }
diff --git a/src/Controller/UserController.php b/src/Controller/UserController.php
index 9949b8c7..0850e6a9 100644
--- a/src/Controller/UserController.php
+++ b/src/Controller/UserController.php
@@ -129,9 +129,9 @@ class UserController extends AdminPages\BaseAdminController
 
                 //We need to stop the execution here, or our permissions changes will be overwritten by the form values
                 return $this->redirectToRoute('user_edit', ['id' => $entity->getID()]);
-            } else {
-                $this->addFlash('danger', 'csfr_invalid');
             }
+
+            $this->addFlash('danger', 'csfr_invalid');
         }
 
         return $this->_edit($entity, $request, $em, $timestamp);
diff --git a/src/DataTables/Column/LocaleDateTimeColumn.php b/src/DataTables/Column/LocaleDateTimeColumn.php
index 3904a4cd..76515a25 100644
--- a/src/DataTables/Column/LocaleDateTimeColumn.php
+++ b/src/DataTables/Column/LocaleDateTimeColumn.php
@@ -45,7 +45,9 @@ class LocaleDateTimeColumn extends AbstractColumn
     {
         if (null === $value) {
             return $this->options['nullValue'];
-        } elseif (!$value instanceof DateTimeInterface) {
+        }
+
+        if (!$value instanceof DateTimeInterface) {
             $value = new DateTime((string) $value);
         }
 
diff --git a/src/DataTables/Filters/Constraints/FilterTrait.php b/src/DataTables/Filters/Constraints/FilterTrait.php
index 988890ba..394f761a 100644
--- a/src/DataTables/Filters/Constraints/FilterTrait.php
+++ b/src/DataTables/Filters/Constraints/FilterTrait.php
@@ -51,7 +51,7 @@ trait FilterTrait
     protected function generateParameterIdentifier(string $property): string
     {
         //Replace all special characters with underscores
-        $property = preg_replace('/[^a-zA-Z0-9_]/', '_', $property);
+        $property = preg_replace('/\W/', '_', $property);
         //Add a random number to the end of the property name for uniqueness
         return $property . '_' . uniqid("", false);
     }
diff --git a/src/DataTables/PartsDataTable.php b/src/DataTables/PartsDataTable.php
index 011c4a8e..c96948b3 100644
--- a/src/DataTables/PartsDataTable.php
+++ b/src/DataTables/PartsDataTable.php
@@ -63,27 +63,19 @@ use Symfony\Contracts\Translation\TranslatorInterface;
 final class PartsDataTable implements DataTableTypeInterface
 {
     private TranslatorInterface $translator;
-    private NodesListBuilder $treeBuilder;
     private AmountFormatter $amountFormatter;
-    private AttachmentURLGenerator $attachmentURLGenerator;
     private Security $security;
 
     private PartDataTableHelper $partDataTableHelper;
 
-    /**
-     * @var EntityURLGenerator
-     */
-    private $urlGenerator;
+    private EntityURLGenerator $urlGenerator;
 
     public function __construct(EntityURLGenerator $urlGenerator, TranslatorInterface $translator,
-        NodesListBuilder $treeBuilder, AmountFormatter $amountFormatter,PartDataTableHelper $partDataTableHelper,
-        AttachmentURLGenerator $attachmentURLGenerator, Security $security)
+        AmountFormatter $amountFormatter,PartDataTableHelper $partDataTableHelper, Security $security)
     {
         $this->urlGenerator = $urlGenerator;
         $this->translator = $translator;
-        $this->treeBuilder = $treeBuilder;
         $this->amountFormatter = $amountFormatter;
-        $this->attachmentURLGenerator = $attachmentURLGenerator;
         $this->security = $security;
         $this->partDataTableHelper = $partDataTableHelper;
     }
diff --git a/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php b/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
index 811facf6..1f7c04e7 100644
--- a/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
+++ b/src/Doctrine/Purger/ResetAutoIncrementORMPurger.php
@@ -53,21 +53,21 @@ class ResetAutoIncrementORMPurger implements PurgerInterface, ORMPurgerInterface
     public const PURGE_MODE_TRUNCATE = 2;
 
     /** @var EntityManagerInterface|null */
-    private $em;
+    private ?EntityManagerInterface $em;
 
     /**
      * If the purge should be done through DELETE or TRUNCATE statements
      *
      * @var int
      */
-    private $purgeMode = self::PURGE_MODE_DELETE;
+    private int $purgeMode = self::PURGE_MODE_DELETE;
 
     /**
      * Table/view names to be excluded from purge
      *
      * @var string[]
      */
-    private $excluded;
+    private array $excluded;
 
     /**
      * Construct new purger instance.
diff --git a/src/Entity/Attachments/AttachmentType.php b/src/Entity/Attachments/AttachmentType.php
index ad7a0e61..33ed8b18 100644
--- a/src/Entity/Attachments/AttachmentType.php
+++ b/src/Entity/Attachments/AttachmentType.php
@@ -51,7 +51,7 @@ class AttachmentType extends AbstractStructuralDBElement
      * @ORM\ManyToOne(targetEntity="AttachmentType", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?AbstractStructuralDBElement $parent;
 
     /**
      * @var string
diff --git a/src/Entity/Base/AbstractStructuralDBElement.php b/src/Entity/Base/AbstractStructuralDBElement.php
index 629669e9..eec1a73e 100644
--- a/src/Entity/Base/AbstractStructuralDBElement.php
+++ b/src/Entity/Base/AbstractStructuralDBElement.php
@@ -94,7 +94,7 @@ abstract class AbstractStructuralDBElement extends AttachmentContainingDBElement
      * @NoneOfItsChildren()
      * @Groups({"include_parents", "import"})
      */
-    protected $parent = null;
+    protected ?AbstractStructuralDBElement $parent = null;
 
     /** @var string[] all names of all parent elements as a array of strings,
      *  the last array element is the name of the element itself
@@ -155,10 +155,8 @@ abstract class AbstractStructuralDBElement extends AttachmentContainingDBElement
             if ($this->getParent() === $another_element) {
                 return true;
             }
-        } else { //If the IDs are defined, we can compare the IDs
-            if ($this->getParent()->getID() === $another_element->getID()) {
-                return true;
-            }
+        } elseif ($this->getParent()->getID() === $another_element->getID()) {
+            return true;
         }
 
         //Otherwise, check recursively
diff --git a/src/Entity/LogSystem/AbstractLogEntry.php b/src/Entity/LogSystem/AbstractLogEntry.php
index 8055a383..2c7c7e40 100644
--- a/src/Entity/LogSystem/AbstractLogEntry.php
+++ b/src/Entity/LogSystem/AbstractLogEntry.php
@@ -183,7 +183,7 @@ abstract class AbstractLogEntry extends AbstractDBElement
     /** @var array The extra data in raw (short form) saved in the DB
      * @ORM\Column(name="extra", type="json")
      */
-    protected $extra = [];
+    protected array $extra = [];
 
     public function __construct()
     {
diff --git a/src/Entity/Parameters/AbstractParameter.php b/src/Entity/Parameters/AbstractParameter.php
index 01aca08a..08e4d7b7 100644
--- a/src/Entity/Parameters/AbstractParameter.php
+++ b/src/Entity/Parameters/AbstractParameter.php
@@ -143,7 +143,7 @@ abstract class AbstractParameter extends AbstractNamedDBElement
      *
      * @var AbstractDBElement|null the element to which this parameter belongs to
      */
-    protected $element;
+    protected ?AbstractDBElement $element;
 
     public function __construct()
     {
diff --git a/src/Entity/Parameters/AttachmentTypeParameter.php b/src/Entity/Parameters/AttachmentTypeParameter.php
index aa39a9a6..89fdbbc3 100644
--- a/src/Entity/Parameters/AttachmentTypeParameter.php
+++ b/src/Entity/Parameters/AttachmentTypeParameter.php
@@ -57,5 +57,5 @@ class AttachmentTypeParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Attachments\AttachmentType", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/CategoryParameter.php b/src/Entity/Parameters/CategoryParameter.php
index f2ce3807..f5989823 100644
--- a/src/Entity/Parameters/CategoryParameter.php
+++ b/src/Entity/Parameters/CategoryParameter.php
@@ -57,5 +57,5 @@ class CategoryParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Category", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/CurrencyParameter.php b/src/Entity/Parameters/CurrencyParameter.php
index c5fa1e2a..4afdedbe 100644
--- a/src/Entity/Parameters/CurrencyParameter.php
+++ b/src/Entity/Parameters/CurrencyParameter.php
@@ -60,5 +60,5 @@ class CurrencyParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\PriceInformations\Currency", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/FootprintParameter.php b/src/Entity/Parameters/FootprintParameter.php
index 9c682720..aa6f803c 100644
--- a/src/Entity/Parameters/FootprintParameter.php
+++ b/src/Entity/Parameters/FootprintParameter.php
@@ -58,5 +58,5 @@ class FootprintParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Footprint", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/GroupParameter.php b/src/Entity/Parameters/GroupParameter.php
index aa15edb8..0d22ae62 100644
--- a/src/Entity/Parameters/GroupParameter.php
+++ b/src/Entity/Parameters/GroupParameter.php
@@ -58,5 +58,5 @@ class GroupParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\UserSystem\Group", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/ManufacturerParameter.php b/src/Entity/Parameters/ManufacturerParameter.php
index 1f01ce4d..547e3b80 100644
--- a/src/Entity/Parameters/ManufacturerParameter.php
+++ b/src/Entity/Parameters/ManufacturerParameter.php
@@ -58,5 +58,5 @@ class ManufacturerParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Manufacturer", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/MeasurementUnitParameter.php b/src/Entity/Parameters/MeasurementUnitParameter.php
index 7ca4b1c5..c95f8844 100644
--- a/src/Entity/Parameters/MeasurementUnitParameter.php
+++ b/src/Entity/Parameters/MeasurementUnitParameter.php
@@ -58,5 +58,5 @@ class MeasurementUnitParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\MeasurementUnit", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/ParametersTrait.php b/src/Entity/Parameters/ParametersTrait.php
index c7ccbddf..f8ac8e78 100644
--- a/src/Entity/Parameters/ParametersTrait.php
+++ b/src/Entity/Parameters/ParametersTrait.php
@@ -52,7 +52,7 @@ trait ParametersTrait
      * @var Collection<int, AbstractParameter>
      * @Assert\Valid()
      */
-    protected $parameters;
+    protected Collection $parameters;
 
     /**
      *  Return all associated specifications.
diff --git a/src/Entity/Parameters/PartParameter.php b/src/Entity/Parameters/PartParameter.php
index 45c566d9..b5d0fbaa 100644
--- a/src/Entity/Parameters/PartParameter.php
+++ b/src/Entity/Parameters/PartParameter.php
@@ -58,5 +58,5 @@ class PartParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Part", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/ProjectParameter.php b/src/Entity/Parameters/ProjectParameter.php
index 2961a843..b4269e9c 100644
--- a/src/Entity/Parameters/ProjectParameter.php
+++ b/src/Entity/Parameters/ProjectParameter.php
@@ -58,5 +58,5 @@ class ProjectParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\ProjectSystem\Project", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/StorelocationParameter.php b/src/Entity/Parameters/StorelocationParameter.php
index 2a7aa202..b236ad1c 100644
--- a/src/Entity/Parameters/StorelocationParameter.php
+++ b/src/Entity/Parameters/StorelocationParameter.php
@@ -58,5 +58,5 @@ class StorelocationParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Storelocation", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parameters/SupplierParameter.php b/src/Entity/Parameters/SupplierParameter.php
index a40e3e92..534cc949 100644
--- a/src/Entity/Parameters/SupplierParameter.php
+++ b/src/Entity/Parameters/SupplierParameter.php
@@ -58,5 +58,5 @@ class SupplierParameter extends AbstractParameter
      * @ORM\ManyToOne(targetEntity="App\Entity\Parts\Supplier", inversedBy="parameters")
      * @ORM\JoinColumn(name="element_id", referencedColumnName="id", nullable=false, onDelete="CASCADE").
      */
-    protected $element;
+    protected ?\App\Entity\Base\AbstractDBElement $element;
 }
diff --git a/src/Entity/Parts/Category.php b/src/Entity/Parts/Category.php
index 8bcf32d2..7dd37c0f 100644
--- a/src/Entity/Parts/Category.php
+++ b/src/Entity/Parts/Category.php
@@ -52,7 +52,7 @@ class Category extends AbstractPartsContainingDBElement
      * @ORM\ManyToOne(targetEntity="Category", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @var string
diff --git a/src/Entity/Parts/Footprint.php b/src/Entity/Parts/Footprint.php
index cac63fe2..079d1168 100644
--- a/src/Entity/Parts/Footprint.php
+++ b/src/Entity/Parts/Footprint.php
@@ -44,7 +44,7 @@ class Footprint extends AbstractPartsContainingDBElement
      * @ORM\ManyToOne(targetEntity="Footprint", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @ORM\OneToMany(targetEntity="Footprint", mappedBy="parent")
diff --git a/src/Entity/Parts/Manufacturer.php b/src/Entity/Parts/Manufacturer.php
index 45e4d140..17ab8543 100644
--- a/src/Entity/Parts/Manufacturer.php
+++ b/src/Entity/Parts/Manufacturer.php
@@ -44,7 +44,7 @@ class Manufacturer extends AbstractCompany
      * @ORM\ManyToOne(targetEntity="Manufacturer", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @ORM\OneToMany(targetEntity="Manufacturer", mappedBy="parent")
diff --git a/src/Entity/Parts/MeasurementUnit.php b/src/Entity/Parts/MeasurementUnit.php
index 5ff9cef4..7ebdfc85 100644
--- a/src/Entity/Parts/MeasurementUnit.php
+++ b/src/Entity/Parts/MeasurementUnit.php
@@ -81,7 +81,7 @@ class MeasurementUnit extends AbstractPartsContainingDBElement
      * @ORM\ManyToOne(targetEntity="MeasurementUnit", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @var Collection<int, MeasurementUnitAttachment>
diff --git a/src/Entity/Parts/Storelocation.php b/src/Entity/Parts/Storelocation.php
index e7a7dfb7..58e2f2e8 100644
--- a/src/Entity/Parts/Storelocation.php
+++ b/src/Entity/Parts/Storelocation.php
@@ -53,7 +53,7 @@ class Storelocation extends AbstractPartsContainingDBElement
      * @ORM\ManyToOne(targetEntity="Storelocation", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @var MeasurementUnit|null The measurement unit, which parts can be stored in here
diff --git a/src/Entity/Parts/Supplier.php b/src/Entity/Parts/Supplier.php
index ae1e4ca1..e6068115 100644
--- a/src/Entity/Parts/Supplier.php
+++ b/src/Entity/Parts/Supplier.php
@@ -56,7 +56,7 @@ class Supplier extends AbstractCompany
      * @ORM\ManyToOne(targetEntity="Supplier", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?\App\Entity\Base\AbstractStructuralDBElement $parent;
 
     /**
      * @ORM\OneToMany(targetEntity="App\Entity\PriceInformations\Orderdetail", mappedBy="supplier")
diff --git a/src/Entity/PriceInformations/Currency.php b/src/Entity/PriceInformations/Currency.php
index f2c44504..4f6e0923 100644
--- a/src/Entity/PriceInformations/Currency.php
+++ b/src/Entity/PriceInformations/Currency.php
@@ -75,7 +75,7 @@ class Currency extends AbstractStructuralDBElement
      * @ORM\ManyToOne(targetEntity="Currency", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?AbstractStructuralDBElement $parent;
 
     /**
      * @var Collection<int, CurrencyAttachment>
diff --git a/src/Entity/PriceInformations/Orderdetail.php b/src/Entity/PriceInformations/Orderdetail.php
index 60f43ee9..c1d182a2 100644
--- a/src/Entity/PriceInformations/Orderdetail.php
+++ b/src/Entity/PriceInformations/Orderdetail.php
@@ -57,7 +57,7 @@ class Orderdetail extends AbstractDBElement implements TimeStampableInterface, N
      * @ORM\OrderBy({"min_discount_quantity" = "ASC"})
      * @Groups({"extended", "full", "import"})
      */
-    protected $pricedetails;
+    protected Collection $pricedetails;
 
     /**
      * @var string
diff --git a/src/Entity/ProjectSystem/Project.php b/src/Entity/ProjectSystem/Project.php
index 8c8192f8..ab0f2739 100644
--- a/src/Entity/ProjectSystem/Project.php
+++ b/src/Entity/ProjectSystem/Project.php
@@ -53,14 +53,14 @@ class Project extends AbstractStructuralDBElement
      * @ORM\ManyToOne(targetEntity="Project", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?AbstractStructuralDBElement $parent;
 
     /**
      * @ORM\OneToMany(targetEntity="ProjectBOMEntry", mappedBy="project", cascade={"persist", "remove"}, orphanRemoval=true)
      * @Assert\Valid()
      * @Groups({"extended", "full"})
      */
-    protected $bom_entries;
+    protected Collection $bom_entries;
 
     /**
      * @ORM\Column(type="integer")
diff --git a/src/Entity/UserSystem/Group.php b/src/Entity/UserSystem/Group.php
index 30bec19c..e07d6fad 100644
--- a/src/Entity/UserSystem/Group.php
+++ b/src/Entity/UserSystem/Group.php
@@ -55,7 +55,7 @@ class Group extends AbstractStructuralDBElement implements HasPermissionsInterfa
      * @ORM\ManyToOne(targetEntity="Group", inversedBy="children")
      * @ORM\JoinColumn(name="parent_id", referencedColumnName="id")
      */
-    protected $parent;
+    protected ?AbstractStructuralDBElement $parent;
 
     /**
      * @ORM\OneToMany(targetEntity="User", mappedBy="group")
@@ -68,7 +68,7 @@ class Group extends AbstractStructuralDBElement implements HasPermissionsInterfa
      * @ORM\Column(type="boolean", name="enforce_2fa")
      * @Groups({"extended", "full", "import"})
      */
-    protected $enforce2FA = false;
+    protected bool $enforce2FA = false;
     /**
      * @var Collection<int, GroupAttachment>
      * @ORM\OneToMany(targetEntity="App\Entity\Attachments\GroupAttachment", mappedBy="element", cascade={"persist", "remove"}, orphanRemoval=true)
diff --git a/src/Entity/UserSystem/PermissionData.php b/src/Entity/UserSystem/PermissionData.php
index 2c84c6e3..90fe3289 100644
--- a/src/Entity/UserSystem/PermissionData.php
+++ b/src/Entity/UserSystem/PermissionData.php
@@ -216,7 +216,7 @@ final class PermissionData implements \JsonSerializable
                 continue;
             }
 
-            $ret[$permission] = array_filter($operations, function ($value) {
+            $ret[$permission] = array_filter($operations, static function ($value) {
                 return $value !== null;
             });
 
diff --git a/src/Entity/UserSystem/User.php b/src/Entity/UserSystem/User.php
index 1850d9f7..77182159 100644
--- a/src/Entity/UserSystem/User.php
+++ b/src/Entity/UserSystem/User.php
@@ -255,10 +255,10 @@ class User extends AttachmentContainingDBElement implements UserInterface, HasPe
      * @Selectable()
      * @Groups({"extended", "full", "import"})
      */
-    protected $currency;
+    protected ?Currency $currency;
 
     /**
-     * @var PermissionData
+     * @var PermissionData|null
      * @ValidPermission()
      * @ORM\Embedded(class="PermissionData", columnPrefix="permissions_")
      * @Groups({"simple", "extended", "full", "import"})
@@ -266,10 +266,10 @@ class User extends AttachmentContainingDBElement implements UserInterface, HasPe
     protected ?PermissionData $permissions = null;
 
     /**
-     * @var DateTime the time until the password reset token is valid
+     * @var DateTime|null the time until the password reset token is valid
      * @ORM\Column(type="datetime", nullable=true, options={"default": null})
      */
-    protected $pw_reset_expires;
+    protected ?DateTime $pw_reset_expires;
 
     /**
      * @var bool True if the user was created by a SAML provider (and therefore cannot change its password)
diff --git a/src/Form/AdminPages/BaseEntityAdminForm.php b/src/Form/AdminPages/BaseEntityAdminForm.php
index 1a95a119..31dd39f0 100644
--- a/src/Form/AdminPages/BaseEntityAdminForm.php
+++ b/src/Form/AdminPages/BaseEntityAdminForm.php
@@ -25,14 +25,12 @@ namespace App\Form\AdminPages;
 use App\Entity\Base\AbstractNamedDBElement;
 use App\Entity\Base\AbstractStructuralDBElement;
 use App\Entity\LabelSystem\LabelProfile;
-use App\Entity\Parameters\AbstractParameter;
 use App\Form\AttachmentFormType;
 use App\Form\ParameterType;
 use App\Form\Type\MasterPictureAttachmentType;
 use App\Form\Type\RichTextEditorType;
 use App\Form\Type\StructuralEntityType;
 use App\Services\LogSystem\EventCommentNeededHelper;
-use FOS\CKEditorBundle\Form\Type\CKEditorType;
 use function get_class;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
diff --git a/src/Form/AttachmentFormType.php b/src/Form/AttachmentFormType.php
index 6f33fde0..23069dd3 100644
--- a/src/Form/AttachmentFormType.php
+++ b/src/Form/AttachmentFormType.php
@@ -27,7 +27,6 @@ use App\Entity\Attachments\AttachmentType;
 use App\Form\Type\StructuralEntityType;
 use App\Services\Attachments\AttachmentManager;
 use App\Services\Attachments\AttachmentSubmitHandler;
-use App\Validator\Constraints\AllowedFileExtension;
 use App\Validator\Constraints\UrlOrBuiltin;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
diff --git a/src/Form/Part/OrderdetailType.php b/src/Form/Part/OrderdetailType.php
index 8489bc73..ece78af5 100644
--- a/src/Form/Part/OrderdetailType.php
+++ b/src/Form/Part/OrderdetailType.php
@@ -27,7 +27,6 @@ use App\Entity\Parts\Supplier;
 use App\Entity\PriceInformations\Orderdetail;
 use App\Entity\PriceInformations\Pricedetail;
 use App\Form\Type\StructuralEntityType;
-use App\Form\WorkaroundCollectionType;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
 use Symfony\Component\Form\Extension\Core\Type\CollectionType;
diff --git a/src/Form/Part/PartBaseType.php b/src/Form/Part/PartBaseType.php
index ef9bd60c..141b5eca 100644
--- a/src/Form/Part/PartBaseType.php
+++ b/src/Form/Part/PartBaseType.php
@@ -36,7 +36,6 @@ use App\Form\Type\MasterPictureAttachmentType;
 use App\Form\Type\RichTextEditorType;
 use App\Form\Type\SIUnitType;
 use App\Form\Type\StructuralEntityType;
-use App\Form\WorkaroundCollectionType;
 use App\Services\LogSystem\EventCommentNeededHelper;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
diff --git a/src/Form/Type/PartLotSelectType.php b/src/Form/Type/PartLotSelectType.php
index 9e93c85b..76e31ecb 100644
--- a/src/Form/Type/PartLotSelectType.php
+++ b/src/Form/Type/PartLotSelectType.php
@@ -43,12 +43,12 @@ class PartLotSelectType extends AbstractType
 
         $resolver->setDefaults([
             'class' => PartLot::class,
-            'choice_label' => ChoiceList::label($this, function (PartLot $part_lot) {
+            'choice_label' => ChoiceList::label($this, static function (PartLot $part_lot) {
                 return ($part_lot->getStorageLocation() ? $part_lot->getStorageLocation()->getFullPath() : '')
                     . ' (' . $part_lot->getName() . '): ' . $part_lot->getAmount();
             }),
             'query_builder' => function (Options $options) {
-                return function (EntityRepository $er) use ($options) {
+                return static function (EntityRepository $er) use ($options) {
                     return $er->createQueryBuilder('l')
                         ->where('l.part = :part')
                         ->setParameter('part', $options['part']);
diff --git a/src/Helpers/Trees/TreeViewNode.php b/src/Helpers/Trees/TreeViewNode.php
index 89e4a02e..f43a1eb6 100644
--- a/src/Helpers/Trees/TreeViewNode.php
+++ b/src/Helpers/Trees/TreeViewNode.php
@@ -30,17 +30,17 @@ use JsonSerializable;
  */
 final class TreeViewNode implements JsonSerializable
 {
-    private $text;
-    private $href;
-    private $nodes;
+    private string $text;
+    private ?string $href;
+    private ?array $nodes;
 
-    private $state = null;
+    private ?TreeViewNodeState $state = null;
 
-    private $tags;
+    private ?array $tags;
 
-    private $id;
+    private ?int $id;
 
-    private $icon;
+    private ?string $icon;
 
     /**
      * Creates a new TreeView node with the given parameters.
diff --git a/src/Helpers/Trees/TreeViewNodeState.php b/src/Helpers/Trees/TreeViewNodeState.php
index 92b4611c..727135bc 100644
--- a/src/Helpers/Trees/TreeViewNodeState.php
+++ b/src/Helpers/Trees/TreeViewNodeState.php
@@ -29,17 +29,17 @@ final class TreeViewNodeState implements JsonSerializable
     /**
      * @var bool|null
      */
-    private $disabled = null;
+    private ?bool $disabled = null;
 
     /**
      * @var bool|null
      */
-    private $expanded = null;
+    private ?bool $expanded = null;
 
     /**
      * @var bool|null
      */
-    private $selected = null;
+    private ?bool $selected = null;
 
     public function getDisabled(): ?bool
     {
diff --git a/src/Migration/AbstractMultiPlatformMigration.php b/src/Migration/AbstractMultiPlatformMigration.php
index 38b86644..ab7e5977 100644
--- a/src/Migration/AbstractMultiPlatformMigration.php
+++ b/src/Migration/AbstractMultiPlatformMigration.php
@@ -21,13 +21,8 @@
 namespace App\Migration;
 
 use Doctrine\DBAL\Connection;
-use Doctrine\DBAL\DBALException;
-use Doctrine\DBAL\Driver\AbstractMySQLDriver;
-use Doctrine\DBAL\Driver\AbstractSQLiteDriver;
 use Doctrine\DBAL\Exception;
 use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
-use Doctrine\DBAL\Platforms\MariaDBPlatform;
-use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Platforms\SqlitePlatform;
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\Migrations\AbstractMigration;
@@ -43,7 +38,7 @@ abstract class AbstractMultiPlatformMigration extends AbstractMigration
     public function __construct(Connection $connection, LoggerInterface $logger)
     {
         $this->logger = $logger;
-        AbstractMigration::__construct($connection, $logger);
+        parent::__construct($connection, $logger);
     }
 
     public function up(Schema $schema): void
diff --git a/src/Repository/UserRepository.php b/src/Repository/UserRepository.php
index b0ccd964..6913dea4 100644
--- a/src/Repository/UserRepository.php
+++ b/src/Repository/UserRepository.php
@@ -35,7 +35,7 @@ use Symfony\Component\Security\Core\User\UserInterface;
  */
 final class UserRepository extends NamedDBElementRepository implements PasswordUpgraderInterface
 {
-    protected $anonymous_user;
+    protected ?User $anonymous_user;
 
     /**
      * Returns the anonymous user.
diff --git a/src/Security/Voter/AttachmentVoter.php b/src/Security/Voter/AttachmentVoter.php
index 135ba57f..25a856a8 100644
--- a/src/Security/Voter/AttachmentVoter.php
+++ b/src/Security/Voter/AttachmentVoter.php
@@ -32,7 +32,7 @@ use function in_array;
 
 class AttachmentVoter extends ExtendedVoter
 {
-    protected $security;
+    protected Security $security;
 
     public function __construct(PermissionManager $resolver, EntityManagerInterface $entityManager, Security $security)
     {
diff --git a/src/Serializer/StructuralElementDenormalizer.php b/src/Serializer/StructuralElementDenormalizer.php
index 5b1396c1..c9880daf 100644
--- a/src/Serializer/StructuralElementDenormalizer.php
+++ b/src/Serializer/StructuralElementDenormalizer.php
@@ -48,7 +48,7 @@ class StructuralElementDenormalizer implements ContextAwareDenormalizerInterface
         return is_array($data)
             && is_subclass_of($type, AbstractStructuralDBElement::class)
             //Only denormalize if we are doing an file import operation
-            && in_array('import', $context['groups'] ?? []);
+            && in_array('import', $context['groups'] ?? [], true);
     }
 
     public function denormalize($data, string $type, string $format = null, array $context = []): ?AbstractStructuralDBElement
diff --git a/src/Services/Attachments/AttachmentSubmitHandler.php b/src/Services/Attachments/AttachmentSubmitHandler.php
index 65e5c7db..db88154d 100644
--- a/src/Services/Attachments/AttachmentSubmitHandler.php
+++ b/src/Services/Attachments/AttachmentSubmitHandler.php
@@ -443,11 +443,13 @@ class AttachmentSubmitHandler
         ];
         if (ctype_digit((string) $maxSize)) {
             return (int) $maxSize;
-        } elseif (preg_match('/^(\d++)('.implode('|', array_keys($factors)).')$/i', $maxSize, $matches)) {
-            return (((int) $matches[1]) * $factors[strtolower($matches[2])]);
-        } else {
-            throw new RuntimeException(sprintf('"%s" is not a valid maximum size.', $maxSize));
         }
+
+        if (preg_match('/^(\d++)('.implode('|', array_keys($factors)).')$/i', $maxSize, $matches)) {
+            return (((int) $matches[1]) * $factors[strtolower($matches[2])]);
+        }
+
+        throw new RuntimeException(sprintf('"%s" is not a valid maximum size.', $maxSize));
     }
 
     /*
diff --git a/src/Services/ImportExportSystem/BOMImporter.php b/src/Services/ImportExportSystem/BOMImporter.php
index d3fa4b9c..4bf9d9a3 100644
--- a/src/Services/ImportExportSystem/BOMImporter.php
+++ b/src/Services/ImportExportSystem/BOMImporter.php
@@ -114,7 +114,7 @@ class BOMImporter
 
         foreach ($csv->getRecords() as $offset => $entry) {
             //Translate the german field names to english
-            $entry = array_combine(array_map(function ($key) {
+            $entry = array_combine(array_map(static function ($key) {
                 return self::MAP_KICAD_PCB_FIELDS[$key] ?? $key;
             }, array_keys($entry)), $entry);
 
diff --git a/src/Services/LabelSystem/BarcodeGenerator.php b/src/Services/LabelSystem/BarcodeGenerator.php
index a192abf2..6bdd021b 100644
--- a/src/Services/LabelSystem/BarcodeGenerator.php
+++ b/src/Services/LabelSystem/BarcodeGenerator.php
@@ -41,6 +41,8 @@ declare(strict_types=1);
 
 namespace App\Services\LabelSystem;
 
+use App\Entity\Base\AbstractDBElement;
+use App\Entity\Base\AbstractStructuralDBElement;
 use App\Entity\LabelSystem\LabelOptions;
 use App\Services\LabelSystem\Barcodes\BarcodeContentGenerator;
 use Com\Tecnick\Barcode\Barcode;
@@ -125,7 +127,7 @@ final class BarcodeGenerator
         return $bobj->getSvgCode();
     }
 
-    public function getContent(LabelOptions $options, object $target): ?string
+    public function getContent(LabelOptions $options, AbstractDBElement $target): ?string
     {
         switch ($options->getBarcodeType()) {
             case 'qr':
diff --git a/src/Services/Trees/TreeViewGenerator.php b/src/Services/Trees/TreeViewGenerator.php
index bc66ba47..e89a3e80 100644
--- a/src/Services/Trees/TreeViewGenerator.php
+++ b/src/Services/Trees/TreeViewGenerator.php
@@ -49,14 +49,14 @@ use function count;
 
 class TreeViewGenerator
 {
-    protected $urlGenerator;
-    protected $em;
-    protected $cache;
-    protected $keyGenerator;
-    protected $translator;
+    protected EntityURLGenerator $urlGenerator;
+    protected EntityManagerInterface $em;
+    protected TagAwareCacheInterface $cache;
+    protected UserCacheKeyGenerator $keyGenerator;
+    protected TranslatorInterface $translator;
 
-    protected $rootNodeExpandedByDefault;
-    protected $rootNodeEnabled;
+    protected bool $rootNodeExpandedByDefault;
+    protected bool $rootNodeEnabled;
 
     public function __construct(EntityURLGenerator $URLGenerator, EntityManagerInterface $em,
         TagAwareCacheInterface $treeCache, UserCacheKeyGenerator $keyGenerator, TranslatorInterface $translator, bool $rootNodeExpandedByDefault, bool $rootNodeEnabled)
diff --git a/src/Services/UserSystem/PermissionSchemaUpdater.php b/src/Services/UserSystem/PermissionSchemaUpdater.php
index e8ebc6d0..f182c018 100644
--- a/src/Services/UserSystem/PermissionSchemaUpdater.php
+++ b/src/Services/UserSystem/PermissionSchemaUpdater.php
@@ -36,11 +36,7 @@ class PermissionSchemaUpdater
     {
         $perm_data = $holder->getPermissions();
 
-        if ($perm_data->getSchemaVersion() < PermissionData::CURRENT_SCHEMA_VERSION) {
-            return true;
-        }
-
-        return false;
+        return $perm_data->getSchemaVersion() < PermissionData::CURRENT_SCHEMA_VERSION;
     }
 
     /**
diff --git a/src/Validator/Constraints/Misc/ValidRange.php b/src/Validator/Constraints/Misc/ValidRange.php
index eb14cf0d..15781498 100644
--- a/src/Validator/Constraints/Misc/ValidRange.php
+++ b/src/Validator/Constraints/Misc/ValidRange.php
@@ -48,5 +48,5 @@ use Symfony\Component\Validator\Constraint;
  */
 class ValidRange extends Constraint
 {
-    public $message = 'validator.invalid_range';
+    public string $message = 'validator.invalid_range';
 }
diff --git a/src/Validator/Constraints/NoLockout.php b/src/Validator/Constraints/NoLockout.php
index 1a515e4d..323dddb4 100644
--- a/src/Validator/Constraints/NoLockout.php
+++ b/src/Validator/Constraints/NoLockout.php
@@ -31,5 +31,5 @@ use Symfony\Component\Validator\Constraint;
  */
 class NoLockout extends Constraint
 {
-    public $message = 'validator.noLockout';
+    public string $message = 'validator.noLockout';
 }
diff --git a/src/Validator/Constraints/NoneOfItsChildren.php b/src/Validator/Constraints/NoneOfItsChildren.php
index e3bed2f8..15d98a2a 100644
--- a/src/Validator/Constraints/NoneOfItsChildren.php
+++ b/src/Validator/Constraints/NoneOfItsChildren.php
@@ -35,9 +35,9 @@ class NoneOfItsChildren extends Constraint
     /**
      * @var string The message used if it is tried to assign a object as its own parent
      */
-    public $self_message = 'validator.noneofitschild.self';
+    public string $self_message = 'validator.noneofitschild.self';
     /**
      * @var string The message used if it is tried to use one of the children for as parent
      */
-    public $children_message = 'validator.noneofitschild.children';
+    public string $children_message = 'validator.noneofitschild.children';
 }
diff --git a/src/Validator/Constraints/UrlOrBuiltin.php b/src/Validator/Constraints/UrlOrBuiltin.php
index d2c5715f..5f68d5f4 100644
--- a/src/Validator/Constraints/UrlOrBuiltin.php
+++ b/src/Validator/Constraints/UrlOrBuiltin.php
@@ -35,5 +35,5 @@ class UrlOrBuiltin extends Url
     /**
      * @var array A list of the placeholders that are treated as builtin
      */
-    public $allowed_placeholders = Attachment::BUILTIN_PLACEHOLDER;
+    public array $allowed_placeholders = Attachment::BUILTIN_PLACEHOLDER;
 }
diff --git a/tests/Controller/AdminPages/AbstractAdminControllerTest.php b/tests/Controller/AdminPages/AbstractAdminControllerTest.php
index 532f0e92..92ba0027 100644
--- a/tests/Controller/AdminPages/AbstractAdminControllerTest.php
+++ b/tests/Controller/AdminPages/AbstractAdminControllerTest.php
@@ -31,8 +31,8 @@ use Symfony\Component\Security\Core\Exception\AccessDeniedException;
  */
 abstract class AbstractAdminControllerTest extends WebTestCase
 {
-    protected static $base_path = 'not_valid';
-    protected static $entity_class = 'not valid';
+    protected static string $base_path = 'not_valid';
+    protected static string $entity_class = 'not valid';
 
     public function readDataProvider(): array
     {
diff --git a/tests/Controller/AdminPages/AttachmentTypeControllerTest.php b/tests/Controller/AdminPages/AttachmentTypeControllerTest.php
index 12233942..e4b47069 100644
--- a/tests/Controller/AdminPages/AttachmentTypeControllerTest.php
+++ b/tests/Controller/AdminPages/AttachmentTypeControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Attachments\AttachmentType;
  */
 class AttachmentTypeControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/attachment_type';
-    protected static $entity_class = AttachmentType::class;
+    protected static string $base_path = '/en'.'/attachment_type';
+    protected static string $entity_class = AttachmentType::class;
 }
diff --git a/tests/Controller/AdminPages/CategoryControllerTest.php b/tests/Controller/AdminPages/CategoryControllerTest.php
index 1a9efee7..df4de1bd 100644
--- a/tests/Controller/AdminPages/CategoryControllerTest.php
+++ b/tests/Controller/AdminPages/CategoryControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\Category;
  */
 class CategoryControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/category';
-    protected static $entity_class = Category::class;
+    protected static string $base_path = '/en'.'/category';
+    protected static string $entity_class = Category::class;
 }
diff --git a/tests/Controller/AdminPages/FootprintControllerTest.php b/tests/Controller/AdminPages/FootprintControllerTest.php
index ac5d8242..972248c9 100644
--- a/tests/Controller/AdminPages/FootprintControllerTest.php
+++ b/tests/Controller/AdminPages/FootprintControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\Footprint;
  */
 class FootprintControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/footprint';
-    protected static $entity_class = Footprint::class;
+    protected static string $base_path = '/en'.'/footprint';
+    protected static string $entity_class = Footprint::class;
 }
diff --git a/tests/Controller/AdminPages/LabelProfileControllerTest.php b/tests/Controller/AdminPages/LabelProfileControllerTest.php
index 80cf8348..0a59ffcc 100644
--- a/tests/Controller/AdminPages/LabelProfileControllerTest.php
+++ b/tests/Controller/AdminPages/LabelProfileControllerTest.php
@@ -46,8 +46,8 @@ use Symfony\Component\Security\Core\Exception\AccessDeniedException;
 
 class LabelProfileControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/label_profile';
-    protected static $entity_class = LabelProfile::class;
+    protected static string $base_path = '/en'.'/label_profile';
+    protected static string $entity_class = LabelProfile::class;
 
     /**
      * Tests if deleting an entity is working.
diff --git a/tests/Controller/AdminPages/ManufacturerControllerTest.php b/tests/Controller/AdminPages/ManufacturerControllerTest.php
index 56b2cd1a..d66441c9 100644
--- a/tests/Controller/AdminPages/ManufacturerControllerTest.php
+++ b/tests/Controller/AdminPages/ManufacturerControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\Manufacturer;
  */
 class ManufacturerControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/manufacturer';
-    protected static $entity_class = Manufacturer::class;
+    protected static string $base_path = '/en'.'/manufacturer';
+    protected static string $entity_class = Manufacturer::class;
 }
diff --git a/tests/Controller/AdminPages/MeasurementUnitControllerTest.php b/tests/Controller/AdminPages/MeasurementUnitControllerTest.php
index 53302e22..62a90cc4 100644
--- a/tests/Controller/AdminPages/MeasurementUnitControllerTest.php
+++ b/tests/Controller/AdminPages/MeasurementUnitControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\MeasurementUnit;
  */
 class MeasurementUnitControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/measurement_unit';
-    protected static $entity_class = MeasurementUnit::class;
+    protected static string $base_path = '/en'.'/measurement_unit';
+    protected static string $entity_class = MeasurementUnit::class;
 }
diff --git a/tests/Controller/AdminPages/ProjectControllerTest.php b/tests/Controller/AdminPages/ProjectControllerTest.php
index 586c1b93..01588e52 100644
--- a/tests/Controller/AdminPages/ProjectControllerTest.php
+++ b/tests/Controller/AdminPages/ProjectControllerTest.php
@@ -31,6 +31,6 @@ use App\Entity\ProjectSystem\Project;
  */
 class ProjectControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/project';
-    protected static $entity_class = Project::class;
+    protected static string $base_path = '/en'.'/project';
+    protected static string $entity_class = Project::class;
 }
diff --git a/tests/Controller/AdminPages/StorelocationControllerTest.php b/tests/Controller/AdminPages/StorelocationControllerTest.php
index 1844c75e..bcfd3212 100644
--- a/tests/Controller/AdminPages/StorelocationControllerTest.php
+++ b/tests/Controller/AdminPages/StorelocationControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\Storelocation;
  */
 class StorelocationControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/store_location';
-    protected static $entity_class = Storelocation::class;
+    protected static string $base_path = '/en'.'/store_location';
+    protected static string $entity_class = Storelocation::class;
 }
diff --git a/tests/Controller/AdminPages/SupplierControllerTest.php b/tests/Controller/AdminPages/SupplierControllerTest.php
index de6f8d7c..f2c3e066 100644
--- a/tests/Controller/AdminPages/SupplierControllerTest.php
+++ b/tests/Controller/AdminPages/SupplierControllerTest.php
@@ -30,6 +30,6 @@ use App\Entity\Parts\Supplier;
  */
 class SupplierControllerTest extends AbstractAdminControllerTest
 {
-    protected static $base_path = '/en'.'/supplier';
-    protected static $entity_class = Supplier::class;
+    protected static string $base_path = '/en'.'/supplier';
+    protected static string $entity_class = Supplier::class;
 }
diff --git a/tests/Controller/RedirectControllerTest.php b/tests/Controller/RedirectControllerTest.php
index 59e884d3..bb4543b6 100644
--- a/tests/Controller/RedirectControllerTest.php
+++ b/tests/Controller/RedirectControllerTest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 namespace App\Tests\Controller;
 
 use App\Entity\UserSystem\User;
+use App\Repository\UserRepository;
 use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 
@@ -32,9 +33,9 @@ use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
  */
 class RedirectControllerTest extends WebTestCase
 {
-    protected $em;
-    protected $userRepo;
-    protected $client;
+    protected EntityManagerInterface $em;
+    protected UserRepository $userRepo;
+    protected \Symfony\Bundle\FrameworkBundle\KernelBrowser $client;
 
     protected function setUp(): void
     {
diff --git a/tests/Entity/Attachments/AttachmentTest.php b/tests/Entity/Attachments/AttachmentTest.php
index 91a3cb53..4a90ac3a 100644
--- a/tests/Entity/Attachments/AttachmentTest.php
+++ b/tests/Entity/Attachments/AttachmentTest.php
@@ -282,7 +282,7 @@ class AttachmentTest extends TestCase
      * @param string $property - property on instance being modified
      * @param mixed  $value    - new value of the property being modified
      */
-    public function setProtectedProperty($object, $property, $value): void
+    public function setProtectedProperty(object $object, string $property, $value): void
     {
         $reflection = new ReflectionClass($object);
         $reflection_property = $reflection->getProperty($property);
diff --git a/tests/Entity/Base/AbstractStructuralDBElementTest.php b/tests/Entity/Base/AbstractStructuralDBElementTest.php
index 9a4104e5..6ff643e2 100644
--- a/tests/Entity/Base/AbstractStructuralDBElementTest.php
+++ b/tests/Entity/Base/AbstractStructuralDBElementTest.php
@@ -33,12 +33,12 @@ use PHPUnit\Framework\TestCase;
  */
 class AbstractStructuralDBElementTest extends TestCase
 {
-    protected $root;
-    protected $child1;
-    protected $child2;
-    protected $child3;
-    protected $child1_1;
-    protected $child1_2;
+    protected AttachmentType $root;
+    protected AttachmentType $child1;
+    protected AttachmentType $child2;
+    protected AttachmentType $child3;
+    protected AttachmentType $child1_1;
+    protected AttachmentType $child1_2;
 
     protected function setUp(): void
     {
diff --git a/tests/Helpers/BBCodeToMarkdownConverterTest.php b/tests/Helpers/BBCodeToMarkdownConverterTest.php
index 35dea60d..a4703d95 100644
--- a/tests/Helpers/BBCodeToMarkdownConverterTest.php
+++ b/tests/Helpers/BBCodeToMarkdownConverterTest.php
@@ -27,7 +27,7 @@ use PHPUnit\Framework\TestCase;
 
 class BBCodeToMarkdownConverterTest extends TestCase
 {
-    protected $converter;
+    protected BBCodeToMarkdownConverter $converter;
 
     protected function setUp(): void
     {
diff --git a/tests/Helpers/Projects/ProjectBuildRequestTest.php b/tests/Helpers/Projects/ProjectBuildRequestTest.php
index 92c61a28..ad14035c 100644
--- a/tests/Helpers/Projects/ProjectBuildRequestTest.php
+++ b/tests/Helpers/Projects/ProjectBuildRequestTest.php
@@ -35,24 +35,24 @@ class ProjectBuildRequestTest extends TestCase
     private MeasurementUnit $float_unit;
 
     /** @var Project */
-    private $project1;
+    private Project $project1;
     /** @var ProjectBOMEntry */
-    private $bom_entry1a;
+    private ProjectBOMEntry $bom_entry1a;
     /** @var ProjectBOMEntry */
-    private $bom_entry1b;
+    private ProjectBOMEntry $bom_entry1b;
     /** @var ProjectBOMEntry */
-    private $bom_entry1c;
+    private ProjectBOMEntry $bom_entry1c;
 
     /** @var PartLot $lot1a */
     private $lot1a;
     /** @var PartLot $lot1b */
     private $lot1b;
-    private $lot2;
+    private PartLot $lot2;
 
     /** @var Part */
-    private $part1;
+    private Part $part1;
     /** @var Part */
-    private $part2;
+    private Part $part2;
 
 
     public function setUp(): void
diff --git a/tests/Helpers/TreeViewNodeTest.php b/tests/Helpers/TreeViewNodeTest.php
index d7ee81f9..9005651d 100644
--- a/tests/Helpers/TreeViewNodeTest.php
+++ b/tests/Helpers/TreeViewNodeTest.php
@@ -30,11 +30,11 @@ class TreeViewNodeTest extends TestCase
     /**
      * @var TreeViewNode
      */
-    protected $node1;
+    protected TreeViewNode $node1;
     /**
      * @var TreeViewNode
      */
-    protected $node2;
+    protected TreeViewNode $node2;
 
     protected function setUp(): void
     {
diff --git a/tests/Services/Attachments/AttachmentPathResolverTest.php b/tests/Services/Attachments/AttachmentPathResolverTest.php
index 76694412..a3f1595f 100644
--- a/tests/Services/Attachments/AttachmentPathResolverTest.php
+++ b/tests/Services/Attachments/AttachmentPathResolverTest.php
@@ -29,8 +29,8 @@ use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 
 class AttachmentPathResolverTest extends WebTestCase
 {
-    protected $media_path;
-    protected $footprint_path;
+    protected string $media_path;
+    protected string $footprint_path;
     protected $projectDir_orig;
     protected $projectDir;
     /**
diff --git a/tests/Services/Attachments/BuiltinAttachmentsFinderTest.php b/tests/Services/Attachments/BuiltinAttachmentsFinderTest.php
index 499ab8f4..597b05ca 100644
--- a/tests/Services/Attachments/BuiltinAttachmentsFinderTest.php
+++ b/tests/Services/Attachments/BuiltinAttachmentsFinderTest.php
@@ -27,7 +27,7 @@ use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 
 class BuiltinAttachmentsFinderTest extends WebTestCase
 {
-    protected static $mock_list = [
+    protected static array $mock_list = [
         '%FOOTPRINTS%/test/test.jpg', '%FOOTPRINTS%/test/test.png', '%FOOTPRINTS%/123.jpg', '%FOOTPRINTS%/123.jpeg',
         '%FOOTPRINTS_3D%/test.jpg', '%FOOTPRINTS_3D%/hallo.txt',
     ];
diff --git a/tests/Services/LabelSystem/LabelTextReplacerTest.php b/tests/Services/LabelSystem/LabelTextReplacerTest.php
index 09635562..dd2e7c7b 100644
--- a/tests/Services/LabelSystem/LabelTextReplacerTest.php
+++ b/tests/Services/LabelSystem/LabelTextReplacerTest.php
@@ -51,12 +51,12 @@ class LabelTextReplacerTest extends WebTestCase
     /**
      * @var LabelTextReplacer
      */
-    protected $service;
+    protected LabelTextReplacer $service;
 
     /**
      * @var Part
      */
-    protected $target;
+    protected Part $target;
 
     protected function setUp(): void
     {
diff --git a/tests/Services/LabelSystem/PlaceholderProviders/PartLotProviderTest.php b/tests/Services/LabelSystem/PlaceholderProviders/PartLotProviderTest.php
index cd9e2c23..83d7f3d9 100644
--- a/tests/Services/LabelSystem/PlaceholderProviders/PartLotProviderTest.php
+++ b/tests/Services/LabelSystem/PlaceholderProviders/PartLotProviderTest.php
@@ -53,9 +53,9 @@ class PartLotProviderTest extends WebTestCase
     /**
      * @var PartLotProvider
      */
-    protected $service;
+    protected PartLotProvider $service;
 
-    protected $target;
+    protected PartLot $target;
 
     protected function setUp(): void
     {
diff --git a/tests/Services/LabelSystem/PlaceholderProviders/PartProviderTest.php b/tests/Services/LabelSystem/PlaceholderProviders/PartProviderTest.php
index a97cb438..8e2b784e 100644
--- a/tests/Services/LabelSystem/PlaceholderProviders/PartProviderTest.php
+++ b/tests/Services/LabelSystem/PlaceholderProviders/PartProviderTest.php
@@ -56,9 +56,9 @@ class PartProviderTest extends WebTestCase
     /**
      * @var PartProvider
      */
-    protected $service;
+    protected PartProvider $service;
 
-    protected $target;
+    protected Part $target;
 
     /**
      * @var \Doctrine\ORM\EntityManager
diff --git a/tests/Services/Misc/FAIconGeneratorTest.php b/tests/Services/Misc/FAIconGeneratorTest.php
index 63015d7b..b2da6a58 100644
--- a/tests/Services/Misc/FAIconGeneratorTest.php
+++ b/tests/Services/Misc/FAIconGeneratorTest.php
@@ -23,7 +23,6 @@ declare(strict_types=1);
 namespace App\Tests\Services\Misc;
 
 use App\Services\Misc\FAIconGenerator;
-use App\Tests\Services\AmountFormatter;
 use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
 
 class FAIconGeneratorTest extends WebTestCase
diff --git a/tests/Services/Parts/PartLotWithdrawAddHelperTest.php b/tests/Services/Parts/PartLotWithdrawAddHelperTest.php
index 33968857..b4404773 100644
--- a/tests/Services/Parts/PartLotWithdrawAddHelperTest.php
+++ b/tests/Services/Parts/PartLotWithdrawAddHelperTest.php
@@ -27,24 +27,24 @@ class PartLotWithdrawAddHelperTest extends WebTestCase
     protected $service;
 
     /** @var Part */
-    private $part;
+    private Part $part;
 
     /** @var Storelocation */
-    private $storageLocation;
+    private Storelocation $storageLocation;
     /** @var Storelocation */
-    private $full_storageLocation;
+    private Storelocation $full_storageLocation;
 
     /** @var PartLot */
-    private $partLot1;
+    private PartLot $partLot1;
     /** @var PartLot */
-    private $partLot2;
+    private PartLot $partLot2;
     /** @var PartLot */
-    private $partLot3;
+    private PartLot $partLot3;
 
     /** @var PartLot */
-    private $fullLot;
+    private PartLot $fullLot;
     /** @var PartLot */
-    private $lotWithUnknownInstock;
+    private PartLot $lotWithUnknownInstock;
 
     protected function setUp(): void
     {
diff --git a/tests/Services/UserSystem/PermissionManagerTest.php b/tests/Services/UserSystem/PermissionManagerTest.php
index 57905253..b6ed5668 100644
--- a/tests/Services/UserSystem/PermissionManagerTest.php
+++ b/tests/Services/UserSystem/PermissionManagerTest.php
@@ -24,7 +24,6 @@ namespace App\Tests\Services\UserSystem;
 
 use App\Entity\UserSystem\Group;
 use App\Entity\UserSystem\PermissionData;
-use App\Entity\UserSystem\PermissionsEmbed;
 use App\Entity\UserSystem\User;
 use App\Services\UserSystem\PermissionManager;
 use InvalidArgumentException;