diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ec5489e36c1..714ce89abf9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,10 +15,8 @@ jobs:
     strategy:
       matrix:
         php:
-          - '7.4'
+          - '8.0'
       fail-fast: false
-    env:
-      PHP_CS_FIXER_FUTURE_MODE: '1'
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -40,7 +38,7 @@ jobs:
     strategy:
       matrix:
         php:
-          - '7.4'
+          - '8.0'
       fail-fast: false
     env:
       APP_DEBUG: '1' # https://github.com/phpstan/phpstan-symfony/issues/37
diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index 1f1d74ce2c6..ac668072a43 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -35,8 +35,6 @@
         '@PHPUnit60Migration:risky' => true,
         '@Symfony' => true,
         '@Symfony:risky' => true,
-        'single_line_comment_style' => false, // Temporary fix for compatibility with PHP 8 attributes, see https://github.com/FriendsOfPHP/PHP-CS-Fixer/pull/5284
-        'comment_to_phpdoc' => true, // Temporary fix for compatibility with PHP 8 attributes, see https://github.com/FriendsOfPHP/PHP-CS-Fixer/pull/5284
         'align_multiline_comment' => [
             'comment_type' => 'phpdocs_like',
         ],
@@ -75,9 +73,10 @@
             ],
         ],
         'no_superfluous_elseif' => true,
-        'no_superfluous_phpdoc_tags' => [
-            'allow_mixed' => false,
-        ],
+        // To re-enable in API Platform 3: https://github.com/symfony/symfony/issues/43021
+        //'no_superfluous_phpdoc_tags' => [
+        //    'allow_mixed' => false,
+        //],
         'no_unset_cast' => true,
         'no_unset_on_property' => true,
         'no_useless_else' => true,
diff --git a/composer.json b/composer.json
index 79f5fd57541..04fc591f3ff 100644
--- a/composer.json
+++ b/composer.json
@@ -72,6 +72,7 @@
         "symfony/form": "^3.4 || ^4.4 || ^5.1",
         "symfony/framework-bundle": "^4.4 || ^5.1",
         "symfony/http-client": "^4.4 || ^5.1",
+        "symfony/intl": "^4.4 || ^5.3",
         "symfony/mercure-bundle": "*",
         "symfony/messenger": "^4.4 || ^5.1",
         "symfony/phpunit-bridge": "^5.1.7",
diff --git a/features/main/custom_normalized.feature b/features/main/custom_normalized.feature
index f9d20c12176..3fd87829059 100644
--- a/features/main/custom_normalized.feature
+++ b/features/main/custom_normalized.feature
@@ -53,7 +53,7 @@ Feature: Using custom normalized entity
     }
     """
 
-  Scenario: Create a resource with a custom normalized dummy and an id
+  Scenario: Update a resource with a custom normalized dummy and an id
     When I add "Content-Type" header equal to "application/json"
     When I add "Accept" header equal to "application/json"
     And I send a "PUT" request to "/related_normalized_dummies/1" with body:
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 520746c369c..710492a3760 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -86,9 +86,6 @@ parameters:
 			path: tests/GraphQl/Type/TypesContainerTest.php
 
 		# Expected, due to PHP 8 attributes
-		- '#ReflectionProperty::getAttributes\(\)#'
-		- '#ReflectionMethod::getAttributes\(\)#'
-		- '#ReflectionClass<object>::getAttributes\(\)#'
 		- '#Constructor of class ApiPlatform\\Core\\Annotation\\ApiResource has an unused parameter#'
 		- '#Constructor of class ApiPlatform\\Core\\Annotation\\ApiProperty has an unused parameter#'
 
diff --git a/src/Api/ResourceClassResolverInterface.php b/src/Api/ResourceClassResolverInterface.php
index 15363cfb02f..022ad61f5eb 100644
--- a/src/Api/ResourceClassResolverInterface.php
+++ b/src/Api/ResourceClassResolverInterface.php
@@ -27,6 +27,7 @@ interface ResourceClassResolverInterface
      *
      * @param string $resourceClass The expected resource class
      * @param bool   $strict        If true, value must match the expected resource class
+     * @param mixed  $value
      *
      * @throws InvalidArgumentException
      */
diff --git a/src/Bridge/Doctrine/Common/DataPersister.php b/src/Bridge/Doctrine/Common/DataPersister.php
index 1d5d95a1d92..4e788c5dac3 100644
--- a/src/Bridge/Doctrine/Common/DataPersister.php
+++ b/src/Bridge/Doctrine/Common/DataPersister.php
@@ -78,6 +78,8 @@ public function remove($data, array $context = [])
 
     /**
      * Gets the Doctrine object manager associated with given data.
+     *
+     * @param mixed $data
      */
     private function getManager($data): ?DoctrineObjectManager
     {
@@ -86,6 +88,8 @@ private function getManager($data): ?DoctrineObjectManager
 
     /**
      * Checks if doctrine does not manage data automatically.
+     *
+     * @param mixed $data
      */
     private function isDeferredExplicit(DoctrineObjectManager $manager, $data): bool
     {
diff --git a/src/Bridge/Doctrine/EventListener/WriteListener.php b/src/Bridge/Doctrine/EventListener/WriteListener.php
index 8f2b348a421..fea014fbe30 100644
--- a/src/Bridge/Doctrine/EventListener/WriteListener.php
+++ b/src/Bridge/Doctrine/EventListener/WriteListener.php
@@ -71,6 +71,8 @@ public function onKernelView(ViewEvent $event): void
 
     /**
      * Gets the manager if applicable.
+     *
+     * @param mixed $data
      */
     private function getManager(string $resourceClass, $data): ?ObjectManager
     {
diff --git a/src/Bridge/Doctrine/MongoDbOdm/CollectionDataProvider.php b/src/Bridge/Doctrine/MongoDbOdm/CollectionDataProvider.php
index 2c0381e444f..de1f94f48a4 100644
--- a/src/Bridge/Doctrine/MongoDbOdm/CollectionDataProvider.php
+++ b/src/Bridge/Doctrine/MongoDbOdm/CollectionDataProvider.php
@@ -56,7 +56,7 @@ public function supports(string $resourceClass, string $operationName = null, ar
      *
      * @throws RuntimeException
      */
-    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, string $operationName = null, array $context = []): iterable
     {
         /** @var DocumentManager $manager */
         $manager = $this->managerRegistry->getManagerForClass($resourceClass);
diff --git a/src/Bridge/Doctrine/MongoDbOdm/Filter/AbstractFilter.php b/src/Bridge/Doctrine/MongoDbOdm/Filter/AbstractFilter.php
index e4a9bcef6d9..483ae408715 100644
--- a/src/Bridge/Doctrine/MongoDbOdm/Filter/AbstractFilter.php
+++ b/src/Bridge/Doctrine/MongoDbOdm/Filter/AbstractFilter.php
@@ -60,6 +60,8 @@ public function apply(Builder $aggregationBuilder, string $resourceClass, string
 
     /**
      * Passes a property through the filter.
+     *
+     * @param mixed $value
      */
     abstract protected function filterProperty(string $property, $value, Builder $aggregationBuilder, string $resourceClass, string $operationName = null, array &$context = []);
 
diff --git a/src/Bridge/Doctrine/MongoDbOdm/Filter/SearchFilter.php b/src/Bridge/Doctrine/MongoDbOdm/Filter/SearchFilter.php
index e14f74888ff..036d55231fa 100644
--- a/src/Bridge/Doctrine/MongoDbOdm/Filter/SearchFilter.php
+++ b/src/Bridge/Doctrine/MongoDbOdm/Filter/SearchFilter.php
@@ -144,6 +144,8 @@ protected function filterProperty(string $property, $value, Builder $aggregation
 
     /**
      * Add equality match stage according to the strategy.
+     *
+     * @param mixed $values
      */
     private function addEqualityMatchStrategy(string $strategy, Builder $aggregationBuilder, string $field, string $matchField, $values, bool $caseSensitive, ClassMetadata $metadata): void
     {
@@ -161,6 +163,8 @@ private function addEqualityMatchStrategy(string $strategy, Builder $aggregation
     /**
      * Get equality match value according to the strategy.
      *
+     * @param mixed $value
+     *
      * @throws InvalidArgumentException If strategy does not exist
      *
      * @return Regex|string
diff --git a/src/Bridge/Doctrine/MongoDbOdm/PropertyInfo/DoctrineExtractor.php b/src/Bridge/Doctrine/MongoDbOdm/PropertyInfo/DoctrineExtractor.php
index 492da9edd0e..5dcdc39f60e 100644
--- a/src/Bridge/Doctrine/MongoDbOdm/PropertyInfo/DoctrineExtractor.php
+++ b/src/Bridge/Doctrine/MongoDbOdm/PropertyInfo/DoctrineExtractor.php
@@ -43,8 +43,10 @@ public function __construct(ObjectManager $objectManager)
 
     /**
      * {@inheritdoc}
+     *
+     * @return string[]|null
      */
-    public function getProperties($class, array $context = [])
+    public function getProperties($class, array $context = []): ?array
     {
         if (null === $metadata = $this->getMetadata($class)) {
             return null;
@@ -55,8 +57,10 @@ public function getProperties($class, array $context = [])
 
     /**
      * {@inheritdoc}
+     *
+     * @return Type[]|null
      */
-    public function getTypes($class, $property, array $context = [])
+    public function getTypes($class, $property, array $context = []): ?array
     {
         if (null === $metadata = $this->getMetadata($class)) {
             return null;
diff --git a/src/Bridge/Doctrine/Orm/CollectionDataProvider.php b/src/Bridge/Doctrine/Orm/CollectionDataProvider.php
index f0cf2b4a2fe..fe4d6c06c8c 100644
--- a/src/Bridge/Doctrine/Orm/CollectionDataProvider.php
+++ b/src/Bridge/Doctrine/Orm/CollectionDataProvider.php
@@ -53,7 +53,7 @@ public function supports(string $resourceClass, string $operationName = null, ar
      *
      * @throws RuntimeException
      */
-    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, string $operationName = null, array $context = []): iterable
     {
         /** @var EntityManagerInterface $manager */
         $manager = $this->managerRegistry->getManagerForClass($resourceClass);
diff --git a/src/Bridge/Doctrine/Orm/Extension/PaginationExtension.php b/src/Bridge/Doctrine/Orm/Extension/PaginationExtension.php
index 39d88c78c3d..d13f2ae8240 100644
--- a/src/Bridge/Doctrine/Orm/Extension/PaginationExtension.php
+++ b/src/Bridge/Doctrine/Orm/Extension/PaginationExtension.php
@@ -155,7 +155,7 @@ public function supportsResult(string $resourceClass, string $operationName = nu
     /**
      * {@inheritdoc}
      */
-    public function getResult(QueryBuilder $queryBuilder, string $resourceClass = null, string $operationName = null, array $context = [])
+    public function getResult(QueryBuilder $queryBuilder, string $resourceClass = null, string $operationName = null, array $context = []): iterable
     {
         $query = $queryBuilder->getQuery();
 
diff --git a/src/Bridge/Doctrine/Orm/Filter/AbstractFilter.php b/src/Bridge/Doctrine/Orm/Filter/AbstractFilter.php
index 5759ad3c3ce..f6501589d1e 100644
--- a/src/Bridge/Doctrine/Orm/Filter/AbstractFilter.php
+++ b/src/Bridge/Doctrine/Orm/Filter/AbstractFilter.php
@@ -75,6 +75,8 @@ public function apply(QueryBuilder $queryBuilder, QueryNameGeneratorInterface $q
 
     /**
      * Passes a property through the filter.
+     *
+     * @param mixed $value
      */
     abstract protected function filterProperty(string $property, $value, QueryBuilder $queryBuilder, QueryNameGeneratorInterface $queryNameGenerator, string $resourceClass, string $operationName = null/*, array $context = []*/);
 
diff --git a/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php b/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
index 35c483032e8..a42b2ba6053 100644
--- a/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
+++ b/src/Bridge/Doctrine/Orm/Filter/SearchFilter.php
@@ -154,6 +154,8 @@ protected function filterProperty(string $property, $value, QueryBuilder $queryB
     /**
      * Adds where clause according to the strategy.
      *
+     * @param mixed $values
+     *
      * @throws InvalidArgumentException If strategy does not exist
      */
     protected function addWhereByStrategy(string $strategy, QueryBuilder $queryBuilder, QueryNameGeneratorInterface $queryNameGenerator, string $alias, string $field, $values, bool $caseSensitive)
diff --git a/src/Bridge/Elasticsearch/DataProvider/CollectionDataProvider.php b/src/Bridge/Elasticsearch/DataProvider/CollectionDataProvider.php
index 0aa6dc4107c..b69f0083a0b 100644
--- a/src/Bridge/Elasticsearch/DataProvider/CollectionDataProvider.php
+++ b/src/Bridge/Elasticsearch/DataProvider/CollectionDataProvider.php
@@ -89,7 +89,7 @@ public function supports(string $resourceClass, ?string $operationName = null, a
     /**
      * {@inheritdoc}
      */
-    public function getCollection(string $resourceClass, ?string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, ?string $operationName = null, array $context = []): iterable
     {
         $documentMetadata = $this->documentMetadataFactory->create($resourceClass);
         $body = [];
diff --git a/src/Bridge/Elasticsearch/Serializer/ItemNormalizer.php b/src/Bridge/Elasticsearch/Serializer/ItemNormalizer.php
index c5bc46ffedf..3f3c6087aa7 100644
--- a/src/Bridge/Elasticsearch/Serializer/ItemNormalizer.php
+++ b/src/Bridge/Elasticsearch/Serializer/ItemNormalizer.php
@@ -52,6 +52,8 @@ public function supportsDenormalization($data, $type, $format = null): bool
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
diff --git a/src/Bridge/Elasticsearch/Serializer/NameConverter/InnerFieldsNameConverter.php b/src/Bridge/Elasticsearch/Serializer/NameConverter/InnerFieldsNameConverter.php
index 3bd4645cb92..d1bbfcdf50e 100644
--- a/src/Bridge/Elasticsearch/Serializer/NameConverter/InnerFieldsNameConverter.php
+++ b/src/Bridge/Elasticsearch/Serializer/NameConverter/InnerFieldsNameConverter.php
@@ -36,7 +36,7 @@ public function __construct(?NameConverterInterface $decorated = null)
     /**
      * {@inheritdoc}
      */
-    public function normalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function normalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         return $this->convertInnerFields($propertyName, true, $class, $format, $context);
     }
@@ -44,7 +44,7 @@ public function normalize($propertyName, string $class = null, string $format =
     /**
      * {@inheritdoc}
      */
-    public function denormalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function denormalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         return $this->convertInnerFields($propertyName, false, $class, $format, $context);
     }
diff --git a/src/Bridge/Symfony/Bundle/Action/SwaggerUiAction.php b/src/Bridge/Symfony/Bundle/Action/SwaggerUiAction.php
index b838a6c851e..c475453ed4e 100644
--- a/src/Bridge/Symfony/Bundle/Action/SwaggerUiAction.php
+++ b/src/Bridge/Symfony/Bundle/Action/SwaggerUiAction.php
@@ -66,6 +66,15 @@ final class SwaggerUiAction
     /**
      * @param int[]      $swaggerVersions
      * @param mixed|null $assetPackage
+     * @param mixed      $formats
+     * @param mixed      $oauthEnabled
+     * @param mixed      $oauthClientId
+     * @param mixed      $oauthClientSecret
+     * @param mixed      $oauthType
+     * @param mixed      $oauthFlow
+     * @param mixed      $oauthTokenUrl
+     * @param mixed      $oauthAuthorizationUrl
+     * @param mixed      $oauthScopes
      */
     public function __construct(ResourceNameCollectionFactoryInterface $resourceNameCollectionFactory, ResourceMetadataFactoryInterface $resourceMetadataFactory, NormalizerInterface $normalizer, ?TwigEnvironment $twig, UrlGeneratorInterface $urlGenerator, string $title = '', string $description = '', string $version = '', $formats = [], $oauthEnabled = false, $oauthClientId = '', $oauthClientSecret = '', $oauthType = '', $oauthFlow = '', $oauthTokenUrl = '', $oauthAuthorizationUrl = '', $oauthScopes = [], bool $showWebby = true, bool $swaggerUiEnabled = false, bool $reDocEnabled = false, bool $graphqlEnabled = false, bool $graphiQlEnabled = false, bool $graphQlPlaygroundEnabled = false, array $swaggerVersions = [2, 3], OpenApiSwaggerUiAction $swaggerUiAction = null, $assetPackage = null)
     {
diff --git a/src/Bridge/Symfony/Bundle/CacheWarmer/CachePoolClearerCacheWarmer.php b/src/Bridge/Symfony/Bundle/CacheWarmer/CachePoolClearerCacheWarmer.php
index 497e5821aa1..a40241b9c76 100644
--- a/src/Bridge/Symfony/Bundle/CacheWarmer/CachePoolClearerCacheWarmer.php
+++ b/src/Bridge/Symfony/Bundle/CacheWarmer/CachePoolClearerCacheWarmer.php
@@ -36,8 +36,10 @@ public function __construct(Psr6CacheClearer $poolClearer, array $pools = [])
 
     /**
      * {@inheritdoc}
+     *
+     * @return string[]
      */
-    public function warmUp($cacheDirectory)
+    public function warmUp($cacheDirectory): array
     {
         foreach ($this->pools as $pool) {
             if ($this->poolClearer->hasPool($pool)) {
diff --git a/src/Bridge/Symfony/Bundle/Command/GraphQlExportCommand.php b/src/Bridge/Symfony/Bundle/Command/GraphQlExportCommand.php
index 2b2402fc54a..acdfa39fde6 100644
--- a/src/Bridge/Symfony/Bundle/Command/GraphQlExportCommand.php
+++ b/src/Bridge/Symfony/Bundle/Command/GraphQlExportCommand.php
@@ -54,6 +54,8 @@ protected function configure(): void
 
     /**
      * {@inheritdoc}
+     *
+     * @return int
      */
     protected function execute(InputInterface $input, OutputInterface $output)
     {
diff --git a/src/Bridge/Symfony/Bundle/Command/OpenApiCommand.php b/src/Bridge/Symfony/Bundle/Command/OpenApiCommand.php
index f117899f705..68314d55098 100644
--- a/src/Bridge/Symfony/Bundle/Command/OpenApiCommand.php
+++ b/src/Bridge/Symfony/Bundle/Command/OpenApiCommand.php
@@ -57,7 +57,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         // Backwards compatibility
         if (2 === $specVersion = (int) $input->getOption('spec-version')) {
diff --git a/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php b/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
index a6b4b386e6b..61198eaceb5 100644
--- a/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
+++ b/src/Bridge/Symfony/Bundle/Command/SwaggerCommand.php
@@ -79,7 +79,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         $io = new SymfonyStyle($input, $output);
 
diff --git a/src/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataProvider.php b/src/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataProvider.php
index 14fd37c1ba1..0790d80da24 100644
--- a/src/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataProvider.php
+++ b/src/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataProvider.php
@@ -45,7 +45,7 @@ public function getContext(): array
         return $this->context;
     }
 
-    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, string $operationName = null, array $context = []): iterable
     {
         $this->context = $context;
         $results = null;
diff --git a/src/Bridge/Symfony/Bundle/DependencyInjection/Configuration.php b/src/Bridge/Symfony/Bundle/DependencyInjection/Configuration.php
index c860f6f02be..8ac24e4cd41 100644
--- a/src/Bridge/Symfony/Bundle/DependencyInjection/Configuration.php
+++ b/src/Bridge/Symfony/Bundle/DependencyInjection/Configuration.php
@@ -47,8 +47,9 @@ final class Configuration implements ConfigurationInterface
 {
     /**
      * {@inheritdoc}
+     * @return TreeBuilder
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         if (method_exists(TreeBuilder::class, 'getRootNode')) {
             $treeBuilder = new TreeBuilder('api_platform');
diff --git a/src/Bridge/Symfony/Bundle/Test/Constraint/MatchesJsonSchema.php b/src/Bridge/Symfony/Bundle/Test/Constraint/MatchesJsonSchema.php
index b7773b2a0c0..0ea9e8641be 100644
--- a/src/Bridge/Symfony/Bundle/Test/Constraint/MatchesJsonSchema.php
+++ b/src/Bridge/Symfony/Bundle/Test/Constraint/MatchesJsonSchema.php
@@ -89,6 +89,8 @@ protected function additionalFailureDescription($other): string
      *
      * Specifically, we should ensure that:
      * 1. a JSON object is represented as a PHP object, not as an associative array.
+     *
+     * @param mixed $document
      */
     private function normalizeJson($document)
     {
diff --git a/src/Bridge/Symfony/Bundle/Test/Response.php b/src/Bridge/Symfony/Bundle/Test/Response.php
index 96e2cd62241..620ffe291a2 100644
--- a/src/Bridge/Symfony/Bundle/Test/Response.php
+++ b/src/Bridge/Symfony/Bundle/Test/Response.php
@@ -65,6 +65,8 @@ public function __construct(HttpFoundationResponse $httpFoundationResponse, Brow
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function getInfo(string $type = null)
     {
diff --git a/src/Bridge/Symfony/Identifier/Normalizer/UlidNormalizer.php b/src/Bridge/Symfony/Identifier/Normalizer/UlidNormalizer.php
index fbfd6387b2d..c5f6576eb62 100644
--- a/src/Bridge/Symfony/Identifier/Normalizer/UlidNormalizer.php
+++ b/src/Bridge/Symfony/Identifier/Normalizer/UlidNormalizer.php
@@ -24,6 +24,8 @@ final class UlidNormalizer implements DenormalizerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
@@ -37,7 +39,7 @@ public function denormalize($data, $class, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsDenormalization($data, $type, $format = null)
+    public function supportsDenormalization($data, $type, $format = null): bool
     {
         return \is_string($data) && is_a($type, Ulid::class, true);
     }
diff --git a/src/Bridge/Symfony/Messenger/DataTransformer.php b/src/Bridge/Symfony/Messenger/DataTransformer.php
index dac49c37d21..181589f4a82 100644
--- a/src/Bridge/Symfony/Messenger/DataTransformer.php
+++ b/src/Bridge/Symfony/Messenger/DataTransformer.php
@@ -33,6 +33,8 @@ public function __construct(ResourceMetadataFactoryInterface $resourceMetadataFa
 
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/src/Bridge/Symfony/Routing/ApiLoader.php b/src/Bridge/Symfony/Routing/ApiLoader.php
index d7390fd7bd8..82eb4e4a4e5 100644
--- a/src/Bridge/Symfony/Routing/ApiLoader.php
+++ b/src/Bridge/Symfony/Routing/ApiLoader.php
@@ -157,7 +157,7 @@ public function load($data, $type = null): RouteCollection
     /**
      * {@inheritdoc}
      */
-    public function supports($resource, $type = null)
+    public function supports($resource, $type = null): bool
     {
         return 'api_platform' === $type;
     }
diff --git a/src/Bridge/Symfony/Routing/IriConverter.php b/src/Bridge/Symfony/Routing/IriConverter.php
index 0fa11e3e53e..4ca381a5834 100644
--- a/src/Bridge/Symfony/Routing/IriConverter.php
+++ b/src/Bridge/Symfony/Routing/IriConverter.php
@@ -66,6 +66,8 @@ public function __construct(PropertyNameCollectionFactoryInterface $propertyName
 
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function getItemFromIri(string $iri, array $context = [])
     {
diff --git a/src/Bridge/Symfony/Routing/Router.php b/src/Bridge/Symfony/Routing/Router.php
index 51dfe827a2e..60984327019 100644
--- a/src/Bridge/Symfony/Routing/Router.php
+++ b/src/Bridge/Symfony/Routing/Router.php
@@ -18,6 +18,7 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Exception\ResourceNotFoundException;
 use Symfony\Component\Routing\RequestContext;
+use Symfony\Component\Routing\RouteCollection;
 use Symfony\Component\Routing\RouterInterface;
 
 /**
@@ -54,7 +55,7 @@ public function setContext(RequestContext $context)
     /**
      * {@inheritdoc}
      */
-    public function getContext()
+    public function getContext(): RequestContext
     {
         return $this->router->getContext();
     }
@@ -62,7 +63,7 @@ public function getContext()
     /**
      * {@inheritdoc}
      */
-    public function getRouteCollection()
+    public function getRouteCollection(): RouteCollection
     {
         return $this->router->getRouteCollection();
     }
@@ -70,7 +71,7 @@ public function getRouteCollection()
     /**
      * {@inheritdoc}
      */
-    public function match($pathInfo)
+    public function match($pathInfo): array
     {
         $baseContext = $this->router->getContext();
         $baseUrl = $baseContext->getBaseUrl();
@@ -101,7 +102,7 @@ public function match($pathInfo)
     /**
      * {@inheritdoc}
      */
-    public function generate($name, $parameters = [], $referenceType = null)
+    public function generate($name, $parameters = [], $referenceType = null): string
     {
         return $this->router->generate($name, $parameters, self::CONST_MAP[$referenceType ?? $this->urlGenerationStrategy]);
     }
diff --git a/src/DataPersister/DataPersisterInterface.php b/src/DataPersister/DataPersisterInterface.php
index a8ab88c04c8..dc2cee68362 100644
--- a/src/DataPersister/DataPersisterInterface.php
+++ b/src/DataPersister/DataPersisterInterface.php
@@ -22,18 +22,24 @@ interface DataPersisterInterface
 {
     /**
      * Is the data supported by the persister?
+     *
+     * @param mixed $data
      */
     public function supports($data): bool;
 
     /**
      * Persists the data.
      *
+     * @param mixed $data
+     *
      * @return object|void Void will not be supported in API Platform 3, an object should always be returned
      */
     public function persist($data);
 
     /**
      * Removes the data.
+     *
+     * @param mixed $data
      */
     public function remove($data);
 }
diff --git a/src/DataProvider/ChainCollectionDataProvider.php b/src/DataProvider/ChainCollectionDataProvider.php
index 72e8668544c..684d64f68d2 100644
--- a/src/DataProvider/ChainCollectionDataProvider.php
+++ b/src/DataProvider/ChainCollectionDataProvider.php
@@ -40,7 +40,7 @@ public function __construct(iterable $dataProviders)
     /**
      * {@inheritdoc}
      */
-    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, string $operationName = null, array $context = []): iterable
     {
         foreach ($this->dataProviders as $dataProvider) {
             try {
diff --git a/src/DataProvider/OperationDataProviderTrait.php b/src/DataProvider/OperationDataProviderTrait.php
index 7e08d768b4d..8f4c62b0b0f 100644
--- a/src/DataProvider/OperationDataProviderTrait.php
+++ b/src/DataProvider/OperationDataProviderTrait.php
@@ -46,10 +46,8 @@ trait OperationDataProviderTrait
 
     /**
      * Retrieves data for a collection operation.
-     *
-     * @return iterable
      */
-    private function getCollectionData(array $attributes, array $context)
+    private function getCollectionData(array $attributes, array $context): iterable
     {
         return $this->collectionDataProvider->getCollection($attributes['resource_class'], $attributes['collection_operation_name'], $context);
     }
@@ -57,6 +55,8 @@ private function getCollectionData(array $attributes, array $context)
     /**
      * Gets data for an item operation.
      *
+     * @param mixed $identifiers
+     *
      * @return object|null
      */
     private function getItemData($identifiers, array $attributes, array $context)
@@ -67,6 +67,8 @@ private function getItemData($identifiers, array $attributes, array $context)
     /**
      * Gets data for a nested operation.
      *
+     * @param mixed $identifiers
+     *
      * @throws RuntimeException
      *
      * @return array|object|null
diff --git a/src/EventListener/SerializeListener.php b/src/EventListener/SerializeListener.php
index b3abea328b2..51fa0a612ef 100644
--- a/src/EventListener/SerializeListener.php
+++ b/src/EventListener/SerializeListener.php
@@ -109,6 +109,8 @@ public function onKernelView(ViewEvent $event): void
     /**
      * Tries to serialize data that are not API resources (e.g. the entrypoint or data returned by a custom controller).
      *
+     * @param mixed $controllerResult
+     *
      * @throws RuntimeException
      */
     private function serializeRawData(ViewEvent $event, Request $request, $controllerResult): void
diff --git a/src/Filter/Validator/ArrayItems.php b/src/Filter/Validator/ArrayItems.php
index e29e7200f84..0b3531c6abf 100644
--- a/src/Filter/Validator/ArrayItems.php
+++ b/src/Filter/Validator/ArrayItems.php
@@ -62,9 +62,12 @@ private function getValue(string $name, array $filterDescription, array $queryPa
 
         $collectionFormat = $filterDescription['swagger']['collectionFormat'] ?? 'csv';
 
-        return explode(self::getSeparator($collectionFormat), $value) ?: [];
+        return explode(self::getSeparator($collectionFormat), $value) ?: []; // @phpstan-ignore-line
     }
 
+    /**
+     * @return non-empty-string
+     */
     private static function getSeparator(string $collectionFormat): string
     {
         switch ($collectionFormat) {
diff --git a/src/Filter/Validator/Required.php b/src/Filter/Validator/Required.php
index 8e2bcee51a5..ca1ac218f17 100644
--- a/src/Filter/Validator/Required.php
+++ b/src/Filter/Validator/Required.php
@@ -72,8 +72,6 @@ private function requestHasQueryParameter(array $queryParameters, string $name):
 
     /**
      * Test if required filter is valid. It validates array notation too like "required[bar]".
-     *
-     * @return ?mixed
      */
     private function requestGetQueryParameter(array $queryParameters, string $name)
     {
diff --git a/src/GraphQl/ExecutorInterface.php b/src/GraphQl/ExecutorInterface.php
index 05f88c0f94b..7149adad53f 100644
--- a/src/GraphQl/ExecutorInterface.php
+++ b/src/GraphQl/ExecutorInterface.php
@@ -30,6 +30,7 @@ interface ExecutorInterface
      *
      * @param mixed|null $rootValue
      * @param mixed|null $context
+     * @param mixed      $source
      */
     public function executeQuery(Schema $schema, $source, $rootValue = null, $context = null, array $variableValues = null, string $operationName = null, callable $fieldResolver = null, array $validationRules = null): ExecutionResult;
 }
diff --git a/src/GraphQl/Type/Definition/IterableType.php b/src/GraphQl/Type/Definition/IterableType.php
index 081cbab4d47..f0e40eb8344 100644
--- a/src/GraphQl/Type/Definition/IterableType.php
+++ b/src/GraphQl/Type/Definition/IterableType.php
@@ -33,6 +33,8 @@ trait IterableTypeParseLiteralTrait
          * {@inheritdoc}
          *
          * @param ObjectValueNode|ListValueNode|IntValueNode|FloatValueNode|StringValueNode|BooleanValueNode|NullValueNode $valueNode
+         *
+         * @return mixed
          */
         public function parseLiteral(/*Node */ $valueNode, ?array $variables = null)
         {
@@ -90,6 +92,8 @@ public function getName(): string
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function serialize($value)
     {
@@ -102,6 +106,8 @@ public function serialize($value)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function parseValue($value)
     {
diff --git a/src/GraphQl/Type/Definition/UploadType.php b/src/GraphQl/Type/Definition/UploadType.php
index 3b61cf54d3c..ec20b49b589 100644
--- a/src/GraphQl/Type/Definition/UploadType.php
+++ b/src/GraphQl/Type/Definition/UploadType.php
@@ -24,6 +24,8 @@ trait UploadTypeParseLiteralTrait
     {
         /**
          * {@inheritdoc}
+         *
+         * @return mixed
          */
         public function parseLiteral(/*Node */ $valueNode, array $variables = null)
         {
@@ -67,6 +69,8 @@ public function getName(): string
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function serialize($value)
     {
diff --git a/src/Hal/Serializer/EntrypointNormalizer.php b/src/Hal/Serializer/EntrypointNormalizer.php
index 2a1b14907ef..c200f810c34 100644
--- a/src/Hal/Serializer/EntrypointNormalizer.php
+++ b/src/Hal/Serializer/EntrypointNormalizer.php
@@ -67,7 +67,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && $data instanceof Entrypoint;
     }
diff --git a/src/Hal/Serializer/ItemNormalizer.php b/src/Hal/Serializer/ItemNormalizer.php
index a6e485d1780..7ae9daf8af7 100644
--- a/src/Hal/Serializer/ItemNormalizer.php
+++ b/src/Hal/Serializer/ItemNormalizer.php
@@ -97,6 +97,8 @@ public function supportsDenormalization($data, $type, $format = null): bool
      * {@inheritdoc}
      *
      * @throws LogicException
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
@@ -225,6 +227,8 @@ private function populateRelation(array $data, $object, ?string $format, array $
     /**
      * Gets the IRI of the given relation.
      *
+     * @param mixed $rel
+     *
      * @throws UnexpectedValueException
      */
     private function getRelationIri($rel): string
diff --git a/src/Hal/Serializer/ObjectNormalizer.php b/src/Hal/Serializer/ObjectNormalizer.php
index 0b3797d982b..b622a710eac 100644
--- a/src/Hal/Serializer/ObjectNormalizer.php
+++ b/src/Hal/Serializer/ObjectNormalizer.php
@@ -95,6 +95,8 @@ public function supportsDenormalization($data, $type, $format = null, array $con
      * {@inheritdoc}
      *
      * @throws LogicException
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
diff --git a/src/Hydra/Serializer/CollectionFiltersNormalizer.php b/src/Hydra/Serializer/CollectionFiltersNormalizer.php
index 0ddf1a40f50..7e5cfb001aa 100644
--- a/src/Hydra/Serializer/CollectionFiltersNormalizer.php
+++ b/src/Hydra/Serializer/CollectionFiltersNormalizer.php
@@ -52,7 +52,7 @@ public function __construct(NormalizerInterface $collectionNormalizer, ResourceM
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $this->collectionNormalizer->supportsNormalization($data, $format);
     }
diff --git a/src/Hydra/Serializer/CollectionNormalizer.php b/src/Hydra/Serializer/CollectionNormalizer.php
index dcfc7ab7c21..a191dd1df48 100644
--- a/src/Hydra/Serializer/CollectionNormalizer.php
+++ b/src/Hydra/Serializer/CollectionNormalizer.php
@@ -59,7 +59,7 @@ public function __construct(ContextBuilderInterface $contextBuilder, ResourceCla
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && is_iterable($data);
     }
diff --git a/src/Hydra/Serializer/DocumentationNormalizer.php b/src/Hydra/Serializer/DocumentationNormalizer.php
index d5dcc96ca60..71186fcb1ad 100644
--- a/src/Hydra/Serializer/DocumentationNormalizer.php
+++ b/src/Hydra/Serializer/DocumentationNormalizer.php
@@ -549,7 +549,7 @@ private function getContext(): array
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null, array $context = [])
+    public function supportsNormalization($data, $format = null, array $context = []): bool
     {
         return self::FORMAT === $format && $data instanceof Documentation;
     }
diff --git a/src/Hydra/Serializer/EntrypointNormalizer.php b/src/Hydra/Serializer/EntrypointNormalizer.php
index 45aa8cfaa46..40d5e45c5a9 100644
--- a/src/Hydra/Serializer/EntrypointNormalizer.php
+++ b/src/Hydra/Serializer/EntrypointNormalizer.php
@@ -73,7 +73,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null, array $context = [])
+    public function supportsNormalization($data, $format = null, array $context = []): bool
     {
         return self::FORMAT === $format && $data instanceof Entrypoint;
     }
diff --git a/src/Hydra/Serializer/ErrorNormalizer.php b/src/Hydra/Serializer/ErrorNormalizer.php
index 6aeee094142..158f797163b 100644
--- a/src/Hydra/Serializer/ErrorNormalizer.php
+++ b/src/Hydra/Serializer/ErrorNormalizer.php
@@ -66,7 +66,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && ($data instanceof \Exception || $data instanceof FlattenException || $data instanceof LegacyFlattenException);
     }
diff --git a/src/Hydra/Serializer/PartialCollectionViewNormalizer.php b/src/Hydra/Serializer/PartialCollectionViewNormalizer.php
index f6a18586b22..a1c6d845bf3 100644
--- a/src/Hydra/Serializer/PartialCollectionViewNormalizer.php
+++ b/src/Hydra/Serializer/PartialCollectionViewNormalizer.php
@@ -103,7 +103,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $this->collectionNormalizer->supportsNormalization($data, $format);
     }
diff --git a/src/Identifier/Normalizer/DateTimeIdentifierDenormalizer.php b/src/Identifier/Normalizer/DateTimeIdentifierDenormalizer.php
index 6a38c121e01..ea9dda77279 100644
--- a/src/Identifier/Normalizer/DateTimeIdentifierDenormalizer.php
+++ b/src/Identifier/Normalizer/DateTimeIdentifierDenormalizer.php
@@ -19,7 +19,12 @@
 
 final class DateTimeIdentifierDenormalizer extends DateTimeNormalizer
 {
-    public function denormalize($data, $class, $format = null, array $context = [])
+    /**
+     * @param mixed|null $format
+     * @param mixed      $data
+     * @param mixed      $class
+     */
+    public function denormalize($data, $class, $format = null, array $context = []): \DateTimeInterface
     {
         try {
             return parent::denormalize($data, $class, $format, $context);
diff --git a/src/JsonApi/Serializer/ConstraintViolationListNormalizer.php b/src/JsonApi/Serializer/ConstraintViolationListNormalizer.php
index 586f4f13cdc..d5c505dc3fb 100644
--- a/src/JsonApi/Serializer/ConstraintViolationListNormalizer.php
+++ b/src/JsonApi/Serializer/ConstraintViolationListNormalizer.php
@@ -56,7 +56,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && $data instanceof ConstraintViolationListInterface;
     }
diff --git a/src/JsonApi/Serializer/EntrypointNormalizer.php b/src/JsonApi/Serializer/EntrypointNormalizer.php
index be4f67d18fb..ee6c74f4e11 100644
--- a/src/JsonApi/Serializer/EntrypointNormalizer.php
+++ b/src/JsonApi/Serializer/EntrypointNormalizer.php
@@ -69,7 +69,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && $data instanceof Entrypoint;
     }
diff --git a/src/JsonApi/Serializer/ErrorNormalizer.php b/src/JsonApi/Serializer/ErrorNormalizer.php
index 6ba2d582728..762dd7cf9ce 100644
--- a/src/JsonApi/Serializer/ErrorNormalizer.php
+++ b/src/JsonApi/Serializer/ErrorNormalizer.php
@@ -63,7 +63,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && ($data instanceof \Exception || $data instanceof FlattenException || $data instanceof LegacyFlattenException);
     }
diff --git a/src/JsonApi/Serializer/ItemNormalizer.php b/src/JsonApi/Serializer/ItemNormalizer.php
index 2beb8cab51a..e7a70278c3e 100644
--- a/src/JsonApi/Serializer/ItemNormalizer.php
+++ b/src/JsonApi/Serializer/ItemNormalizer.php
@@ -130,6 +130,8 @@ public function supportsDenormalization($data, $type, $format = null): bool
      * {@inheritdoc}
      *
      * @throws NotNormalizableValueException
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
@@ -361,6 +363,8 @@ private function getPopulatedRelations($object, ?string $format, array $context,
 
     /**
      * Populates included keys.
+     *
+     * @param mixed $object
      */
     private function getRelatedResources($object, ?string $format, array $context, array $relationships): array
     {
diff --git a/src/JsonApi/Serializer/ReservedAttributeNameConverter.php b/src/JsonApi/Serializer/ReservedAttributeNameConverter.php
index 9eb3948eaaa..d78fd0a22fd 100644
--- a/src/JsonApi/Serializer/ReservedAttributeNameConverter.php
+++ b/src/JsonApi/Serializer/ReservedAttributeNameConverter.php
@@ -41,7 +41,7 @@ public function __construct(NameConverterInterface $nameConverter = null)
     /**
      * {@inheritdoc}
      */
-    public function normalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function normalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         if (null !== $this->nameConverter) {
             $propertyName = $this->nameConverter->normalize($propertyName, $class, $format, $context);
@@ -57,7 +57,7 @@ public function normalize($propertyName, string $class = null, string $format =
     /**
      * {@inheritdoc}
      */
-    public function denormalize($propertyName, string $class = null, string $format = null, array $context = [])
+    public function denormalize($propertyName, string $class = null, string $format = null, array $context = []): string
     {
         if (\in_array($propertyName, self::JSON_API_RESERVED_ATTRIBUTES, true)) {
             $propertyName = substr($propertyName, 1);
diff --git a/src/JsonLd/AnonymousContextBuilderInterface.php b/src/JsonLd/AnonymousContextBuilderInterface.php
index a13ef3428ed..55d466aa1ef 100644
--- a/src/JsonLd/AnonymousContextBuilderInterface.php
+++ b/src/JsonLd/AnonymousContextBuilderInterface.php
@@ -25,6 +25,8 @@ interface AnonymousContextBuilderInterface extends ContextBuilderInterface
     /**
      * Creates a JSON-LD context based on the given object.
      * Usually this is used with an Input or Output DTO object.
+     *
+     * @param mixed $object
      */
     public function getAnonymousResourceContext($object, array $context = [], int $referenceType = UrlGeneratorInterface::ABS_PATH): array;
 }
diff --git a/src/JsonLd/Serializer/ItemNormalizer.php b/src/JsonLd/Serializer/ItemNormalizer.php
index 793eba67639..4a87887d385 100644
--- a/src/JsonLd/Serializer/ItemNormalizer.php
+++ b/src/JsonLd/Serializer/ItemNormalizer.php
@@ -105,6 +105,8 @@ public function supportsDenormalization($data, $type, $format = null): bool
      * {@inheritdoc}
      *
      * @throws NotNormalizableValueException
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
diff --git a/src/JsonSchema/Command/JsonSchemaGenerateCommand.php b/src/JsonSchema/Command/JsonSchemaGenerateCommand.php
index c492b6f3528..9be6a2c03d3 100644
--- a/src/JsonSchema/Command/JsonSchemaGenerateCommand.php
+++ b/src/JsonSchema/Command/JsonSchemaGenerateCommand.php
@@ -61,7 +61,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         $io = new SymfonyStyle($input, $output);
 
diff --git a/src/Metadata/Property/PropertyMetadata.php b/src/Metadata/Property/PropertyMetadata.php
index 7a84532d3dd..d2968b96bca 100644
--- a/src/Metadata/Property/PropertyMetadata.php
+++ b/src/Metadata/Property/PropertyMetadata.php
@@ -372,6 +372,8 @@ public function getDefault()
 
     /**
      * Returns a new instance with the given default value for the property.
+     *
+     * @param mixed $default
      */
     public function withDefault($default): self
     {
@@ -391,6 +393,8 @@ public function getExample()
 
     /**
      * Returns a new instance with the given example.
+     *
+     * @param mixed $example
      */
     public function withExample($example): self
     {
diff --git a/src/Metadata/Property/PropertyNameCollection.php b/src/Metadata/Property/PropertyNameCollection.php
index 785a6ef8919..1564c2afb1c 100644
--- a/src/Metadata/Property/PropertyNameCollection.php
+++ b/src/Metadata/Property/PropertyNameCollection.php
@@ -36,7 +36,8 @@ public function __construct(array $properties = [])
     /**
      * {@inheritdoc}
      */
-    public function getIterator()
+    #[\ReturnTypeWillChange]
+    public function getIterator(): \Traversable
     {
         return new \ArrayIterator($this->properties);
     }
@@ -44,7 +45,8 @@ public function getIterator()
     /**
      * {@inheritdoc}
      */
-    public function count()
+    #[\ReturnTypeWillChange]
+    public function count(): int
     {
         return \count($this->properties);
     }
diff --git a/src/Metadata/Resource/Factory/AnnotationResourceMetadataFactory.php b/src/Metadata/Resource/Factory/AnnotationResourceMetadataFactory.php
index f6efada1fab..f1986cb8076 100644
--- a/src/Metadata/Resource/Factory/AnnotationResourceMetadataFactory.php
+++ b/src/Metadata/Resource/Factory/AnnotationResourceMetadataFactory.php
@@ -121,6 +121,8 @@ private function createMetadata(ApiResource $annotation, ResourceMetadata $paren
 
     /**
      * Creates a new instance of metadata if the property is not already set.
+     *
+     * @param mixed $value
      */
     private function createWith(ResourceMetadata $resourceMetadata, string $property, $value): ResourceMetadata
     {
diff --git a/src/Problem/Serializer/ErrorNormalizer.php b/src/Problem/Serializer/ErrorNormalizer.php
index 29c39fd91c5..42053b63565 100644
--- a/src/Problem/Serializer/ErrorNormalizer.php
+++ b/src/Problem/Serializer/ErrorNormalizer.php
@@ -65,7 +65,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return self::FORMAT === $format && ($data instanceof \Exception || $data instanceof FlattenException || $data instanceof LegacyFlattenException);
     }
diff --git a/src/Serializer/AbstractCollectionNormalizer.php b/src/Serializer/AbstractCollectionNormalizer.php
index 4af7d4c456e..200d0e79652 100644
--- a/src/Serializer/AbstractCollectionNormalizer.php
+++ b/src/Serializer/AbstractCollectionNormalizer.php
@@ -52,6 +52,8 @@ public function __construct(ResourceClassResolverInterface $resourceClassResolve
 
     /**
      * {@inheritdoc}
+     *
+     * @return bool
      */
     public function supportsNormalization($data, $format = null)
     {
@@ -92,6 +94,7 @@ public function normalize($object, $format = null, array $context = [])
      * Normalizes a raw collection (not API resources).
      *
      * @param string|null $format
+     * @param mixed       $object
      */
     protected function normalizeRawCollection($object, $format = null, array $context = []): array
     {
diff --git a/src/Serializer/AbstractItemNormalizer.php b/src/Serializer/AbstractItemNormalizer.php
index 3e41e9da00d..d5d30e1e7f9 100644
--- a/src/Serializer/AbstractItemNormalizer.php
+++ b/src/Serializer/AbstractItemNormalizer.php
@@ -96,6 +96,8 @@ public function __construct(PropertyNameCollectionFactoryInterface $propertyName
 
     /**
      * {@inheritdoc}
+     *
+     * @return bool
      */
     public function supportsNormalization($data, $format = null)
     {
@@ -173,6 +175,8 @@ public function normalize($object, $format = null, array $context = [])
 
     /**
      * {@inheritdoc}
+     *
+     * @return bool
      */
     public function supportsDenormalization($data, $type, $format = null)
     {
@@ -181,6 +185,8 @@ public function supportsDenormalization($data, $type, $format = null)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
@@ -259,6 +265,8 @@ public function denormalize($data, $class, $format = null, array $context = [])
      * {@inheritdoc}
      *
      * @internal
+     *
+     * @return object
      */
     protected function instantiateObject(array &$data, $class, array &$context, \ReflectionClass $reflectionClass, $allowedAttributes, string $format = null)
     {
@@ -344,6 +352,8 @@ protected function createConstructorArgument($parameterData, string $key, \Refle
      * {@inheritdoc}
      *
      * Unused in this context.
+     *
+     * @return string[]
      */
     protected function extractAttributes($object, $format = null, array $context = [])
     {
@@ -378,6 +388,8 @@ protected function getAllowedAttributes($classOrObject, array $context, $attribu
 
     /**
      * {@inheritdoc}
+     *
+     * @return bool
      */
     protected function isAllowedAttribute($classOrObject, $attribute, $format = null, array $context = [])
     {
@@ -408,6 +420,8 @@ protected function setAttributeValue($object, $attribute, $value, $format = null
     /**
      * Validates the type of the value. Allows using integers as floats for JSON formats.
      *
+     * @param mixed $value
+     *
      * @throws InvalidArgumentException
      */
     protected function validateType(string $attribute, Type $type, $value, string $format = null)
@@ -427,6 +441,8 @@ protected function validateType(string $attribute, Type $type, $value, string $f
     /**
      * Denormalizes a collection of objects.
      *
+     * @param mixed $value
+     *
      * @throws InvalidArgumentException
      */
     protected function denormalizeCollection(string $attribute, PropertyMetadata $propertyMetadata, Type $type, string $className, $value, ?string $format, array $context): array
@@ -453,6 +469,8 @@ protected function denormalizeCollection(string $attribute, PropertyMetadata $pr
     /**
      * Denormalizes a relation.
      *
+     * @param mixed $value
+     *
      * @throws LogicException
      * @throws UnexpectedValueException
      * @throws ItemNotFoundException
@@ -554,6 +572,8 @@ protected function createRelationSerializationContext(string $resourceClass, arr
      *
      * @throws UnexpectedValueException
      * @throws LogicException
+     *
+     * @return mixed
      */
     protected function getAttributeValue($object, $attribute, $format = null, array $context = [])
     {
@@ -699,6 +719,8 @@ protected function getDataTransformer($data, string $to, array $context = []): ?
     /**
      * For a given resource, it returns an output representation if any
      * If not, the resource is returned.
+     *
+     * @param mixed $object
      */
     protected function transformOutput($object, array $context = [], string $outputClass = null)
     {
@@ -841,6 +863,7 @@ private function createAttributeValue($attribute, $value, $format = null, array
      * Sets a value of the object using the PropertyAccess component.
      *
      * @param object $object
+     * @param mixed  $value
      */
     private function setValue($object, string $attributeName, $value)
     {
diff --git a/src/Serializer/ItemNormalizer.php b/src/Serializer/ItemNormalizer.php
index 293b7955766..581c1c8ed0b 100644
--- a/src/Serializer/ItemNormalizer.php
+++ b/src/Serializer/ItemNormalizer.php
@@ -48,6 +48,8 @@ public function __construct(PropertyNameCollectionFactoryInterface $propertyName
      * {@inheritdoc}
      *
      * @throws NotNormalizableValueException
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
diff --git a/src/Serializer/JsonEncoder.php b/src/Serializer/JsonEncoder.php
index 197bc7d0d28..def8dff9de5 100644
--- a/src/Serializer/JsonEncoder.php
+++ b/src/Serializer/JsonEncoder.php
@@ -55,7 +55,7 @@ public function __construct(string $format, BaseJsonEncoder $jsonEncoder = null)
     /**
      * {@inheritdoc}
      */
-    public function supportsEncoding($format)
+    public function supportsEncoding($format): bool
     {
         return $this->format === $format;
     }
@@ -63,7 +63,7 @@ public function supportsEncoding($format)
     /**
      * {@inheritdoc}
      */
-    public function encode($data, $format, array $context = [])
+    public function encode($data, $format, array $context = []): string
     {
         return $this->jsonEncoder->encode($data, $format, $context);
     }
@@ -71,13 +71,15 @@ public function encode($data, $format, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsDecoding($format)
+    public function supportsDecoding($format): bool
     {
         return $this->format === $format;
     }
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function decode($data, $format, array $context = [])
     {
diff --git a/src/Swagger/Serializer/ApiGatewayNormalizer.php b/src/Swagger/Serializer/ApiGatewayNormalizer.php
index f726881982d..f271dbfa081 100644
--- a/src/Swagger/Serializer/ApiGatewayNormalizer.php
+++ b/src/Swagger/Serializer/ApiGatewayNormalizer.php
@@ -118,7 +118,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $this->documentationNormalizer->supportsNormalization($data, $format);
     }
diff --git a/src/Test/DoctrineMongoDbOdmTestCase.php b/src/Test/DoctrineMongoDbOdmTestCase.php
index de245448aa0..2dd6f9bc9db 100644
--- a/src/Test/DoctrineMongoDbOdmTestCase.php
+++ b/src/Test/DoctrineMongoDbOdmTestCase.php
@@ -28,6 +28,8 @@
 class DoctrineMongoDbOdmTestCase extends TestCase
 {
     /**
+     * @param mixed $paths
+     *
      * @return DocumentManager
      */
     public static function createTestDocumentManager($paths = [])
diff --git a/src/Util/IriHelper.php b/src/Util/IriHelper.php
index 384ca8dbb15..3687ee3efdf 100644
--- a/src/Util/IriHelper.php
+++ b/src/Util/IriHelper.php
@@ -56,6 +56,7 @@ public static function parseIri(string $iri, string $pageParameterName): array
      * Gets a collection IRI for the given parameters.
      *
      * @param float $page
+     * @param mixed $urlGenerationStrategy
      */
     public static function createIri(array $parts, array $parameters, string $pageParameterName = null, float $page = null, $urlGenerationStrategy = UrlGeneratorInterface::ABS_PATH): string
     {
diff --git a/tests/Api/CachedIdentifiersExtractorTest.php b/tests/Api/CachedIdentifiersExtractorTest.php
index 78b6458caa5..173f00db033 100644
--- a/tests/Api/CachedIdentifiersExtractorTest.php
+++ b/tests/Api/CachedIdentifiersExtractorTest.php
@@ -45,6 +45,9 @@ public function itemProvider()
 
     /**
      * @dataProvider itemProvider
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testFirstPass($item, $expected)
     {
@@ -81,6 +84,9 @@ public function testFirstPass($item, $expected)
 
     /**
      * @dataProvider itemProvider
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testSecondPass($item, $expected)
     {
@@ -146,6 +152,9 @@ public function identifiersRelatedProvider()
 
     /**
      * @dataProvider identifiersRelatedProvider
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testFirstPassWithRelated($item, $expected)
     {
@@ -181,6 +190,9 @@ public function testFirstPassWithRelated($item, $expected)
 
     /**
      * @dataProvider identifiersRelatedProvider
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testSecondPassWithRelated($item, $expected)
     {
diff --git a/tests/Api/IdentifiersExtractorTest.php b/tests/Api/IdentifiersExtractorTest.php
index c45eeccb21f..e8d14bc2f63 100644
--- a/tests/Api/IdentifiersExtractorTest.php
+++ b/tests/Api/IdentifiersExtractorTest.php
@@ -72,6 +72,9 @@ public function itemProvider()
 
     /**
      * @dataProvider itemProvider
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testGetIdentifiersFromItem($item, $expected)
     {
@@ -101,6 +104,9 @@ public function itemProviderComposite()
 
     /**
      * @dataProvider itemProviderComposite
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testGetCompositeIdentifiersFromItem($item, $expected)
     {
@@ -138,6 +144,9 @@ public function itemProviderRelated()
 
     /**
      * @dataProvider itemProviderRelated
+     *
+     * @param mixed $item
+     * @param mixed $expected
      */
     public function testGetRelatedIdentifiersFromItem($item, $expected)
     {
diff --git a/tests/Behat/DoctrineContext.php b/tests/Behat/DoctrineContext.php
index 0946ef12f07..cd7f51bbb2d 100644
--- a/tests/Behat/DoctrineContext.php
+++ b/tests/Behat/DoctrineContext.php
@@ -312,6 +312,8 @@ public function thereAreFooObjectsWithFakeNames(int $nb)
 
     /**
      * @Given there are :nb fooDummy objects with fake names
+     *
+     * @param mixed $nb
      */
     public function thereAreFooDummyObjectsWithFakeNames($nb)
     {
@@ -1500,6 +1502,8 @@ public function thereIsADummyDtoCustom()
 
     /**
      * @Given there are :nb DummyDtoCustom
+     *
+     * @param mixed $nb
      */
     public function thereAreNbDummyDtoCustom($nb)
     {
diff --git a/tests/Behat/JsonApiContext.php b/tests/Behat/JsonApiContext.php
index 1154ef235c9..5e26c61218c 100644
--- a/tests/Behat/JsonApiContext.php
+++ b/tests/Behat/JsonApiContext.php
@@ -86,6 +86,8 @@ public function theJsonShouldBeValidAccordingToTheJsonApiSchema()
 
     /**
      * @Then the JSON node :node should be an empty array
+     *
+     * @param mixed $node
      */
     public function theJsonNodeShouldBeAnEmptyArray($node)
     {
@@ -97,6 +99,8 @@ public function theJsonNodeShouldBeAnEmptyArray($node)
 
     /**
      * @Then the JSON node :node should be a number
+     *
+     * @param mixed $node
      */
     public function theJsonNodeShouldBeANumber($node)
     {
@@ -107,6 +111,8 @@ public function theJsonNodeShouldBeANumber($node)
 
     /**
      * @Then the JSON node :node should not be an empty string
+     *
+     * @param mixed $node
      */
     public function theJsonNodeShouldNotBeAnEmptyString($node)
     {
@@ -118,6 +124,8 @@ public function theJsonNodeShouldNotBeAnEmptyString($node)
     /**
      * @Then the JSON node :node should be sorted
      * @Then the JSON should be sorted
+     *
+     * @param mixed $node
      */
     public function theJsonNodeShouldBeSorted($node = '')
     {
diff --git a/tests/Bridge/Doctrine/Common/DataPersisterTest.php b/tests/Bridge/Doctrine/Common/DataPersisterTest.php
index 97c08d8e610..c0d9a6b0a49 100644
--- a/tests/Bridge/Doctrine/Common/DataPersisterTest.php
+++ b/tests/Bridge/Doctrine/Common/DataPersisterTest.php
@@ -130,6 +130,10 @@ public function getTrackingPolicyParameters()
 
     /**
      * @dataProvider getTrackingPolicyParameters
+     *
+     * @param mixed $metadataClass
+     * @param mixed $deferredExplicit
+     * @param mixed $persisted
      */
     public function testTrackingPolicy($metadataClass, $deferredExplicit, $persisted)
     {
diff --git a/tests/Bridge/Doctrine/MongoDbOdm/PaginatorTest.php b/tests/Bridge/Doctrine/MongoDbOdm/PaginatorTest.php
index 9ad1843629f..ce91a418141 100644
--- a/tests/Bridge/Doctrine/MongoDbOdm/PaginatorTest.php
+++ b/tests/Bridge/Doctrine/MongoDbOdm/PaginatorTest.php
@@ -31,6 +31,12 @@ class PaginatorTest extends TestCase
 
     /**
      * @dataProvider initializeProvider
+     *
+     * @param mixed $firstResult
+     * @param mixed $maxResults
+     * @param mixed $totalItems
+     * @param mixed $currentPage
+     * @param mixed $lastPage
      */
     public function testInitialize($firstResult, $maxResults, $totalItems, $currentPage, $lastPage)
     {
diff --git a/tests/Bridge/Doctrine/MongoDbOdm/PropertyInfo/Fixtures/DoctrineFooType.php b/tests/Bridge/Doctrine/MongoDbOdm/PropertyInfo/Fixtures/DoctrineFooType.php
index 0e35d094bb9..4d55ca4a579 100644
--- a/tests/Bridge/Doctrine/MongoDbOdm/PropertyInfo/Fixtures/DoctrineFooType.php
+++ b/tests/Bridge/Doctrine/MongoDbOdm/PropertyInfo/Fixtures/DoctrineFooType.php
@@ -23,6 +23,8 @@ class DoctrineFooType extends Type
 {
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function convertToDatabaseValue($value)
     {
@@ -38,6 +40,8 @@ public function convertToDatabaseValue($value)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function convertToPHPValue($value)
     {
diff --git a/tests/Bridge/Doctrine/Orm/PaginatorTest.php b/tests/Bridge/Doctrine/Orm/PaginatorTest.php
index 791b49ef0a4..c850ce43218 100644
--- a/tests/Bridge/Doctrine/Orm/PaginatorTest.php
+++ b/tests/Bridge/Doctrine/Orm/PaginatorTest.php
@@ -26,6 +26,12 @@ class PaginatorTest extends TestCase
 
     /**
      * @dataProvider initializeProvider
+     *
+     * @param mixed $firstResult
+     * @param mixed $maxResults
+     * @param mixed $totalItems
+     * @param mixed $currentPage
+     * @param mixed $lastPage
      */
     public function testInitialize($firstResult, $maxResults, $totalItems, $currentPage, $lastPage)
     {
diff --git a/tests/Bridge/Symfony/Bundle/Action/SwaggerUiActionTest.php b/tests/Bridge/Symfony/Bundle/Action/SwaggerUiActionTest.php
index ae1c6d3391d..d3c9836d29d 100644
--- a/tests/Bridge/Symfony/Bundle/Action/SwaggerUiActionTest.php
+++ b/tests/Bridge/Symfony/Bundle/Action/SwaggerUiActionTest.php
@@ -46,6 +46,8 @@ class SwaggerUiActionTest extends TestCase
     /**
      * @dataProvider getInvokeParameters
      * @group legacy
+     *
+     * @param mixed $twigProphecy
      */
     public function testInvoke(Request $request, $twigProphecy)
     {
diff --git a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataCollectorTest.php b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataCollectorTest.php
index b87dcf64ebe..e8d640433bf 100644
--- a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataCollectorTest.php
+++ b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataCollectorTest.php
@@ -47,6 +47,10 @@ public function testGetCollection($provider, $context, $expected)
     /**
      * @dataProvider deprecatedDataProviderProvider
      * @group legacy
+     *
+     * @param mixed $provider
+     * @param mixed $context
+     * @param mixed $expected
      */
     public function testDeprecatedGetCollection($provider, $context, $expected)
     {
diff --git a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainItemDataCollectorTest.php b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainItemDataCollectorTest.php
index 32c7a63ae87..8a37bc26adf 100644
--- a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainItemDataCollectorTest.php
+++ b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainItemDataCollectorTest.php
@@ -48,6 +48,10 @@ public function testGetItem($provider, $context, $expected)
     /**
      * @dataProvider deprecatedDataProviderProvider
      * @group legacy
+     *
+     * @param mixed $provider
+     * @param mixed $context
+     * @param mixed $expected
      */
     public function testDeprecatedGetItem($provider, $context, $expected)
     {
diff --git a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainSubresourceDataCollectorTest.php b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainSubresourceDataCollectorTest.php
index 2ea4d3e0a40..029d731067d 100644
--- a/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainSubresourceDataCollectorTest.php
+++ b/tests/Bridge/Symfony/Bundle/DataProvider/TraceableChainSubresourceDataCollectorTest.php
@@ -47,6 +47,10 @@ public function testGetSubresource($provider, $context, $expected)
     /**
      * @dataProvider deprecatedDataProviderProvider
      * @group legacy
+     *
+     * @param mixed $provider
+     * @param mixed $context
+     * @param mixed $expected
      */
     public function testDeprecatedGetSubResource($provider, $context, $expected)
     {
diff --git a/tests/Bridge/Symfony/Bundle/DependencyInjection/ConfigurationTest.php b/tests/Bridge/Symfony/Bundle/DependencyInjection/ConfigurationTest.php
index 3133bca92e1..8707fb3e4bd 100644
--- a/tests/Bridge/Symfony/Bundle/DependencyInjection/ConfigurationTest.php
+++ b/tests/Bridge/Symfony/Bundle/DependencyInjection/ConfigurationTest.php
@@ -271,6 +271,8 @@ public function invalidHttpStatusCodeProvider()
 
     /**
      * @dataProvider invalidHttpStatusCodeProvider
+     *
+     * @param mixed $invalidHttpStatusCode
      */
     public function testExceptionToStatusConfigWithInvalidHttpStatusCode($invalidHttpStatusCode)
     {
@@ -300,6 +302,8 @@ public function invalidHttpStatusCodeValueProvider()
 
     /**
      * @dataProvider invalidHttpStatusCodeValueProvider
+     *
+     * @param mixed $invalidHttpStatusCodeValue
      */
     public function testExceptionToStatusConfigWithInvalidHttpStatusCodeValue($invalidHttpStatusCodeValue)
     {
diff --git a/tests/Bridge/Symfony/Bundle/SwaggerUi/SwaggerUiActionTest.php b/tests/Bridge/Symfony/Bundle/SwaggerUi/SwaggerUiActionTest.php
index 126a3b8bc10..8f156633fc2 100644
--- a/tests/Bridge/Symfony/Bundle/SwaggerUi/SwaggerUiActionTest.php
+++ b/tests/Bridge/Symfony/Bundle/SwaggerUi/SwaggerUiActionTest.php
@@ -47,6 +47,8 @@ class SwaggerUiActionTest extends TestCase
 
     /**
      * @dataProvider getInvokeParameters
+     *
+     * @param mixed $twigProphecy
      */
     public function testInvoke(Request $request, $twigProphecy)
     {
diff --git a/tests/Bridge/Symfony/Bundle/Test/ClientTest.php b/tests/Bridge/Symfony/Bundle/Test/ClientTest.php
index adc443dcfad..034bf8bfa39 100644
--- a/tests/Bridge/Symfony/Bundle/Test/ClientTest.php
+++ b/tests/Bridge/Symfony/Bundle/Test/ClientTest.php
@@ -93,6 +93,8 @@ public function testDefaultHeaders(): void
 
     /**
      * @dataProvider authBasicProvider
+     *
+     * @param mixed $basic
      */
     public function testAuthBasic($basic): void
     {
diff --git a/tests/DataProvider/ArrayPaginatorTest.php b/tests/DataProvider/ArrayPaginatorTest.php
index 5d0269a5b45..f6029082359 100644
--- a/tests/DataProvider/ArrayPaginatorTest.php
+++ b/tests/DataProvider/ArrayPaginatorTest.php
@@ -23,6 +23,13 @@ class ArrayPaginatorTest extends TestCase
 {
     /**
      * @dataProvider initializeProvider
+     *
+     * @param mixed $firstResult
+     * @param mixed $maxResults
+     * @param mixed $currentItems
+     * @param mixed $totalItems
+     * @param mixed $currentPage
+     * @param mixed $lastPage
      */
     public function testInitialize(array $results, $firstResult, $maxResults, $currentItems, $totalItems, $currentPage, $lastPage)
     {
diff --git a/tests/EventListener/AddFormatListenerTest.php b/tests/EventListener/AddFormatListenerTest.php
index cbe005a030d..96bbe7663ef 100644
--- a/tests/EventListener/AddFormatListenerTest.php
+++ b/tests/EventListener/AddFormatListenerTest.php
@@ -362,6 +362,8 @@ public function testResourceClassSupportedRequestFormat(): void
      * @group legacy
      * @expectedDeprecation Passing an array or an instance of "ApiPlatform\Core\Api\FormatsProviderInterface" as 2nd parameter of the constructor of "ApiPlatform\Core\EventListener\AddFormatListener" is deprecated since API Platform 2.5, pass an instance of "ApiPlatform\Core\Metadata\Resource\Factory\ResourceMetadataFactoryInterface" instead
      * @dataProvider legacyFormatsProvider
+     *
+     * @param mixed $formatsProvider
      */
     public function testLegacyFormatsParameter($formatsProvider): void
     {
diff --git a/tests/Fixtures/ArrayAccessible.php b/tests/Fixtures/ArrayAccessible.php
index 92073f5d942..2f0a9e19b66 100644
--- a/tests/Fixtures/ArrayAccessible.php
+++ b/tests/Fixtures/ArrayAccessible.php
@@ -22,11 +22,16 @@ public function __construct(array $array = [])
         $this->array = $array;
     }
 
-    public function offsetExists($offset)
+    #[\ReturnTypeWillChange]
+    public function offsetExists($offset): bool
     {
         return \array_key_exists($offset, $this->array);
     }
 
+    /**
+     * @return mixed
+     */
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->array[$offset];
@@ -46,7 +51,8 @@ public function offsetUnset($offset): void
         unset($this->array[$offset]);
     }
 
-    public function getIterator()
+    #[\ReturnTypeWillChange]
+    public function getIterator(): \Traversable
     {
         return new \ArrayIterator($this->array);
     }
diff --git a/tests/Fixtures/TestBundle/Controller/MongoDbOdm/DummyValidationController.php b/tests/Fixtures/TestBundle/Controller/MongoDbOdm/DummyValidationController.php
index 2bc9b6c3973..dc9ef69b3f8 100644
--- a/tests/Fixtures/TestBundle/Controller/MongoDbOdm/DummyValidationController.php
+++ b/tests/Fixtures/TestBundle/Controller/MongoDbOdm/DummyValidationController.php
@@ -25,6 +25,8 @@ class DummyValidationController
      *     path="/dummy_validation/validation_groups",
      *     defaults={"_api_resource_class"=DummyValidation::class, "_api_collection_operation_name"="post_validation_groups"}
      * )
+     *
+     * @param mixed $data
      */
     public function postValidationGroups($data)
     {
@@ -38,6 +40,8 @@ public function postValidationGroups($data)
      *     path="/dummy_validation/validation_sequence",
      *     defaults={"_api_resource_class"=DummyValidation::class, "_api_collection_operation_name"="post_validation_sequence"}
      * )
+     *
+     * @param mixed $data
      */
     public function postValidationSequence($data)
     {
diff --git a/tests/Fixtures/TestBundle/Controller/Orm/DummyValidationController.php b/tests/Fixtures/TestBundle/Controller/Orm/DummyValidationController.php
index d4e0c0bb522..f5872ebd2d9 100644
--- a/tests/Fixtures/TestBundle/Controller/Orm/DummyValidationController.php
+++ b/tests/Fixtures/TestBundle/Controller/Orm/DummyValidationController.php
@@ -25,6 +25,8 @@ class DummyValidationController
      *     path="/dummy_validation/validation_groups",
      *     defaults={"_api_resource_class"=DummyValidation::class, "_api_collection_operation_name"="post_validation_groups"}
      * )
+     *
+     * @param mixed $data
      */
     public function postValidationGroups($data)
     {
@@ -38,6 +40,8 @@ public function postValidationGroups($data)
      *     path="/dummy_validation/validation_sequence",
      *     defaults={"_api_resource_class"=DummyValidation::class, "_api_collection_operation_name"="post_validation_sequence"}
      * )
+     *
+     * @param mixed $data
      */
     public function postValidationSequence($data)
     {
diff --git a/tests/Fixtures/TestBundle/DataProvider/DummyDtoNoInputCollectionDataProvider.php b/tests/Fixtures/TestBundle/DataProvider/DummyDtoNoInputCollectionDataProvider.php
index ff2fffe5d33..dcb9ee42a56 100644
--- a/tests/Fixtures/TestBundle/DataProvider/DummyDtoNoInputCollectionDataProvider.php
+++ b/tests/Fixtures/TestBundle/DataProvider/DummyDtoNoInputCollectionDataProvider.php
@@ -45,7 +45,7 @@ public function supports(string $resourceClass, string $operationName = null, ar
     /**
      * {@inheritdoc}
      */
-    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
+    public function getCollection(string $resourceClass, string $operationName = null, array $context = []): iterable
     {
         /** @var DummyDtoNoInput[]|DummyDtoNoInputDocument[] $dummyDtos */
         $dummyDtos = $this->registry->getManagerForClass($resourceClass)->getRepository($resourceClass)->findAll();
diff --git a/tests/Fixtures/TestBundle/DataProvider/GeneratorDataProvider.php b/tests/Fixtures/TestBundle/DataProvider/GeneratorDataProvider.php
index 38c5b199a8e..00f337595ea 100644
--- a/tests/Fixtures/TestBundle/DataProvider/GeneratorDataProvider.php
+++ b/tests/Fixtures/TestBundle/DataProvider/GeneratorDataProvider.php
@@ -24,7 +24,7 @@ public function supports(string $resourceClass, string $operationName = null, ar
         return SecuredDummy::class === $resourceClass && 'get_from_data_provider_generator' === $operationName;
     }
 
-    public function getCollection(string $resourceClass, string $operationName = null)
+    public function getCollection(string $resourceClass, string $operationName = null): iterable
     {
         yield from [new class() {
         }, new class() {
diff --git a/tests/Fixtures/TestBundle/DataProvider/ResourceInterfaceImplementationDataProvider.php b/tests/Fixtures/TestBundle/DataProvider/ResourceInterfaceImplementationDataProvider.php
index dd994ac5f0c..c68bcbdbdac 100644
--- a/tests/Fixtures/TestBundle/DataProvider/ResourceInterfaceImplementationDataProvider.php
+++ b/tests/Fixtures/TestBundle/DataProvider/ResourceInterfaceImplementationDataProvider.php
@@ -35,7 +35,7 @@ public function getItem(string $resourceClass, $id, string $operationName = null
         return null;
     }
 
-    public function getCollection(string $resourceClass, string $operationName = null)
+    public function getCollection(string $resourceClass, string $operationName = null): iterable
     {
         yield (new ResourceInterfaceImplementation())->setFoo('item1');
         yield (new ResourceInterfaceImplementation())->setFoo('item2');
diff --git a/tests/Fixtures/TestBundle/DataTransformer/CustomInputDtoDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/CustomInputDtoDataTransformer.php
index 24683213917..edeac806881 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/CustomInputDtoDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/CustomInputDtoDataTransformer.php
@@ -23,6 +23,8 @@ final class CustomInputDtoDataTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/CustomOutputDtoDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/CustomOutputDtoDataTransformer.php
index 66936c0cfa4..8450b5155d7 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/CustomOutputDtoDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/CustomOutputDtoDataTransformer.php
@@ -22,6 +22,8 @@ final class CustomOutputDtoDataTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/DummyDtoNoInputToOutputDtoDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/DummyDtoNoInputToOutputDtoDataTransformer.php
index aa35c9c9eba..0779d70a35e 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/DummyDtoNoInputToOutputDtoDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/DummyDtoNoInputToOutputDtoDataTransformer.php
@@ -23,6 +23,8 @@ final class DummyDtoNoInputToOutputDtoDataTransformer implements DataTransformer
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/InitializeInputDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/InitializeInputDataTransformer.php
index 9f151b0a0c5..099a9124125 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/InitializeInputDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/InitializeInputDataTransformer.php
@@ -23,6 +23,8 @@ final class InitializeInputDataTransformer implements DataTransformerInitializer
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/InputDtoDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/InputDtoDataTransformer.php
index 9f5a5ee3e05..a12326415a5 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/InputDtoDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/InputDtoDataTransformer.php
@@ -24,6 +24,8 @@ final class InputDtoDataTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/OutputDtoDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/OutputDtoDataTransformer.php
index 3b1644edc23..d55d2769954 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/OutputDtoDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/OutputDtoDataTransformer.php
@@ -24,6 +24,8 @@ final class OutputDtoDataTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/OutputDtoSameClassTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/OutputDtoSameClassTransformer.php
index 53a222e3cb0..eacfebe31ca 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/OutputDtoSameClassTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/OutputDtoSameClassTransformer.php
@@ -27,6 +27,8 @@ final class OutputDtoSameClassTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/RPCOutputDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/RPCOutputDataTransformer.php
index 54940515aa2..22aeb173567 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/RPCOutputDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/RPCOutputDataTransformer.php
@@ -22,6 +22,8 @@ final class RPCOutputDataTransformer implements DataTransformerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordInputDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordInputDataTransformer.php
index 55c64cac077..4df062afe35 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordInputDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordInputDataTransformer.php
@@ -23,6 +23,8 @@ final class RecoverPasswordInputDataTransformer implements DataTransformerInterf
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($data, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordOutputDataTransformer.php b/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordOutputDataTransformer.php
index 0921243610f..d7542a3bb4d 100644
--- a/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordOutputDataTransformer.php
+++ b/tests/Fixtures/TestBundle/DataTransformer/RecoverPasswordOutputDataTransformer.php
@@ -22,6 +22,8 @@ final class RecoverPasswordOutputDataTransformer implements DataTransformerInter
 {
     /**
      * {@inheritdoc}
+     *
+     * @return object
      */
     public function transform($object, string $to, array $context = [])
     {
diff --git a/tests/Fixtures/TestBundle/Document/Answer.php b/tests/Fixtures/TestBundle/Document/Answer.php
index 49126ff7ab9..c9971f64414 100644
--- a/tests/Fixtures/TestBundle/Document/Answer.php
+++ b/tests/Fixtures/TestBundle/Document/Answer.php
@@ -16,6 +16,7 @@
 use ApiPlatform\Core\Annotation\ApiResource;
 use ApiPlatform\Core\Annotation\ApiSubresource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
 use Symfony\Component\Serializer\Annotation as Serializer;
 
@@ -61,22 +62,16 @@ public function __construct()
 
     /**
      * Get id.
-     *
-     * @return string
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Set content.
-     *
-     * @param string $content
-     *
-     * @return Answer
      */
-    public function setContent($content)
+    public function setContent(string $content): self
     {
         $this->content = $content;
 
@@ -85,22 +80,16 @@ public function setContent($content)
 
     /**
      * Get content.
-     *
-     * @return string
      */
-    public function getContent()
+    public function getContent(): ?string
     {
         return $this->content;
     }
 
     /**
      * Set question.
-     *
-     * @param Question $question
-     *
-     * @return Answer
      */
-    public function setQuestion(Question $question = null)
+    public function setQuestion(Question $question = null): self
     {
         $this->question = $question;
 
@@ -109,25 +98,21 @@ public function setQuestion(Question $question = null)
 
     /**
      * Get question.
-     *
-     * @return Question
      */
-    public function getQuestion()
+    public function getQuestion(): ?Question
     {
         return $this->question;
     }
 
     /**
      * Get related question.
-     *
-     * @return ArrayCollection
      */
-    public function getRelatedQuestions()
+    public function getRelatedQuestions(): Collection
     {
         return $this->relatedQuestions;
     }
 
-    public function addRelatedQuestion(Question $question)
+    public function addRelatedQuestion(Question $question): void
     {
         $this->relatedQuestions->add($question);
     }
diff --git a/tests/Fixtures/TestBundle/Document/CompositeItem.php b/tests/Fixtures/TestBundle/Document/CompositeItem.php
index 2020aeee04d..d1cedd9b77b 100644
--- a/tests/Fixtures/TestBundle/Document/CompositeItem.php
+++ b/tests/Fixtures/TestBundle/Document/CompositeItem.php
@@ -44,20 +44,16 @@ class CompositeItem
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets field1.
-     *
-     * @return string|null
      */
-    public function getField1()
+    public function getField1(): ?string
     {
         return $this->field1;
     }
@@ -74,10 +70,8 @@ public function setField1($field1 = null)
 
     /**
      * Gets compositeValues.
-     *
-     * @return CompositeRelation
      */
-    public function getCompositeValues()
+    public function getCompositeValues(): ?CompositeRelation
     {
         return $this->compositeValues;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CompositeLabel.php b/tests/Fixtures/TestBundle/Document/CompositeLabel.php
index 4d6d26e3a90..eac0b3af7fb 100644
--- a/tests/Fixtures/TestBundle/Document/CompositeLabel.php
+++ b/tests/Fixtures/TestBundle/Document/CompositeLabel.php
@@ -38,20 +38,16 @@ class CompositeLabel
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets value.
-     *
-     * @return string|null
      */
-    public function getValue()
+    public function getValue(): ?string
     {
         return $this->value;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CompositePrimitiveItem.php b/tests/Fixtures/TestBundle/Document/CompositePrimitiveItem.php
index 5b6ce0282a6..9cf495df0a1 100644
--- a/tests/Fixtures/TestBundle/Document/CompositePrimitiveItem.php
+++ b/tests/Fixtures/TestBundle/Document/CompositePrimitiveItem.php
@@ -52,30 +52,24 @@ public function __construct(string $name, int $year)
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets name.
-     *
-     * @return string
      */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
     /**
      * Gets year.
-     *
-     * @return int
      */
-    public function getYear()
+    public function getYear(): ?int
     {
         return $this->year;
     }
@@ -90,10 +84,8 @@ public function setDescription(string $description)
 
     /**
      * Gets description.
-     *
-     * @return string
      */
-    public function getDescription()
+    public function getDescription(): ?string
     {
         return $this->description;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CompositeRelation.php b/tests/Fixtures/TestBundle/Document/CompositeRelation.php
index c5e9d54b7f1..005d31479cf 100644
--- a/tests/Fixtures/TestBundle/Document/CompositeRelation.php
+++ b/tests/Fixtures/TestBundle/Document/CompositeRelation.php
@@ -50,20 +50,16 @@ class CompositeRelation
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets value.
-     *
-     * @return string|null
      */
-    public function getValue()
+    public function getValue(): ?string
     {
         return $this->value;
     }
@@ -80,10 +76,8 @@ public function setValue($value = null)
 
     /**
      * Gets compositeItem.
-     *
-     * @return CompositeItem
      */
-    public function getCompositeItem()
+    public function getCompositeItem(): ?CompositeItem
     {
         return $this->compositeItem;
     }
@@ -100,10 +94,8 @@ public function setCompositeItem(CompositeItem $compositeItem)
 
     /**
      * Gets compositeLabel.
-     *
-     * @return CompositeLabel
      */
-    public function getCompositeLabel()
+    public function getCompositeLabel(): ?CompositeLabel
     {
         return $this->compositeLabel;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Content.php b/tests/Fixtures/TestBundle/Document/Content.php
index 461f33a5c5b..48d8bdadea0 100644
--- a/tests/Fixtures/TestBundle/Document/Content.php
+++ b/tests/Fixtures/TestBundle/Document/Content.php
@@ -147,7 +147,10 @@ public function getStatus(): ContentStatus
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return [
diff --git a/tests/Fixtures/TestBundle/Document/CustomActionDummy.php b/tests/Fixtures/TestBundle/Document/CustomActionDummy.php
index 9aae6262bf2..e5a893839ae 100644
--- a/tests/Fixtures/TestBundle/Document/CustomActionDummy.php
+++ b/tests/Fixtures/TestBundle/Document/CustomActionDummy.php
@@ -49,7 +49,7 @@ class CustomActionDummy
      */
     private $foo = '';
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CustomIdentifierDummy.php b/tests/Fixtures/TestBundle/Document/CustomIdentifierDummy.php
index a6453482073..001cc81f7f3 100644
--- a/tests/Fixtures/TestBundle/Document/CustomIdentifierDummy.php
+++ b/tests/Fixtures/TestBundle/Document/CustomIdentifierDummy.php
@@ -38,18 +38,12 @@ class CustomIdentifierDummy
      */
     private $name;
 
-    /**
-     * @return int
-     */
-    public function getCustomId()
+    public function getCustomId(): int
     {
         return $this->customId;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CustomNormalizedDummy.php b/tests/Fixtures/TestBundle/Document/CustomNormalizedDummy.php
index 0c47c8ed86a..1d3b89775e4 100644
--- a/tests/Fixtures/TestBundle/Document/CustomNormalizedDummy.php
+++ b/tests/Fixtures/TestBundle/Document/CustomNormalizedDummy.php
@@ -33,7 +33,7 @@
 class CustomNormalizedDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      * @Groups({"input", "output"})
@@ -41,7 +41,7 @@ class CustomNormalizedDummy
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field
      * @Assert\NotBlank
@@ -51,7 +51,7 @@ class CustomNormalizedDummy
     private $name;
 
     /**
-     * @var string The dummy name alias
+     * @var string|null The dummy name alias
      *
      * @ODM\Field(nullable=true)
      * @ApiProperty(iri="https://schema.org/alternateName")
@@ -59,10 +59,7 @@ class CustomNormalizedDummy
      */
     private $alias;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -75,18 +72,12 @@ public function setName($name)
         $this->name = $name;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    /**
-     * @return string
-     */
-    public function getAlias()
+    public function getAlias(): ?string
     {
         return $this->alias;
     }
@@ -99,10 +90,7 @@ public function setAlias($alias)
         $this->alias = $alias;
     }
 
-    /**
-     * @return string
-     */
-    public function getPersonalizedAlias()
+    public function getPersonalizedAlias(): ?string
     {
         return $this->alias;
     }
diff --git a/tests/Fixtures/TestBundle/Document/CustomWritableIdentifierDummy.php b/tests/Fixtures/TestBundle/Document/CustomWritableIdentifierDummy.php
index c10720b19c8..2df004d8526 100644
--- a/tests/Fixtures/TestBundle/Document/CustomWritableIdentifierDummy.php
+++ b/tests/Fixtures/TestBundle/Document/CustomWritableIdentifierDummy.php
@@ -46,18 +46,12 @@ public function setSlug($slug)
         $this->slug = $slug;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): string
     {
         return $this->slug;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Dummy.php b/tests/Fixtures/TestBundle/Document/Dummy.php
index 8e276fe7939..f1e8f9eca65 100644
--- a/tests/Fixtures/TestBundle/Document/Dummy.php
+++ b/tests/Fixtures/TestBundle/Document/Dummy.php
@@ -17,6 +17,7 @@
 use ApiPlatform\Core\Annotation\ApiResource;
 use ApiPlatform\Core\Annotation\ApiSubresource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
 use Symfony\Component\Validator\Constraints as Assert;
 
@@ -48,14 +49,14 @@
 class Dummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int", nullable=true)
      */
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field(type="string")
      * @Assert\NotBlank
@@ -64,7 +65,7 @@ class Dummy
     private $name;
 
     /**
-     * @var string The dummy name alias
+     * @var string|null The dummy name alias
      *
      * @ODM\Field(nullable=true)
      * @ApiProperty(iri="https://schema.org/alternateName")
@@ -72,12 +73,12 @@ class Dummy
     private $alias;
 
     /**
-     * @var array foo
+     * @var array|null foo
      */
     private $foo;
 
     /**
-     * @var string A short description of the item
+     * @var string|null A short description of the item
      *
      * @ODM\Field(type="string", nullable=true)
      * @ApiProperty(iri="https://schema.org/description")
@@ -85,21 +86,21 @@ class Dummy
     public $description;
 
     /**
-     * @var string A dummy
+     * @var string|null A dummy
      *
      * @ODM\Field(nullable=true)
      */
     public $dummy;
 
     /**
-     * @var bool A dummy boolean
+     * @var bool|null A dummy boolean
      *
      * @ODM\Field(type="bool", nullable=true)
      */
     public $dummyBoolean;
 
     /**
-     * @var \DateTime A dummy date
+     * @var \DateTime|null A dummy date
      *
      * @ODM\Field(type="date", nullable=true)
      * @ApiProperty(iri="http://schema.org/DateTime")
@@ -107,28 +108,28 @@ class Dummy
     public $dummyDate;
 
     /**
-     * @var string A dummy float
+     * @var float|null A dummy float
      *
      * @ODM\Field(type="float", nullable=true)
      */
     public $dummyFloat;
 
     /**
-     * @var string A dummy price
+     * @var float|null A dummy price
      *
      * @ODM\Field(type="float", nullable=true)
      */
     public $dummyPrice;
 
     /**
-     * @var RelatedDummy A related dummy
+     * @var RelatedDummy|null A related dummy
      *
      * @ODM\ReferenceOne(targetDocument=RelatedDummy::class, storeAs="id", nullable=true)
      */
     public $relatedDummy;
 
     /**
-     * @var ArrayCollection Several dummies
+     * @var Collection Several dummies
      *
      * @ODM\ReferenceMany(targetDocument=RelatedDummy::class, storeAs="id", nullable=true)
      * @ApiSubresource
@@ -150,27 +151,27 @@ class Dummy
     public $arrayData;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      */
     public $nameConverted;
 
     /**
-     * @var RelatedOwnedDummy
+     * @var RelatedOwnedDummy|null
      *
      * @ODM\ReferenceOne(targetDocument=RelatedOwnedDummy::class, cascade={"persist"}, mappedBy="owningDummy", nullable=true)
      */
     public $relatedOwnedDummy;
 
     /**
-     * @var RelatedOwningDummy
+     * @var RelatedOwningDummy|null
      *
      * @ODM\ReferenceOne(targetDocument=RelatedOwningDummy::class, cascade={"persist"}, inversedBy="ownedDummy", nullable=true, storeAs="id")
      */
     public $relatedOwningDummy;
 
-    public static function staticMethod()
+    public static function staticMethod(): void
     {
     }
 
@@ -312,18 +313,12 @@ public function setRelatedOwningDummy(RelatedOwningDummy $relatedOwningDummy)
         $this->relatedOwningDummy = $relatedOwningDummy;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
 
-    /**
-     * @param bool $dummyBoolean
-     */
-    public function setDummyBoolean($dummyBoolean)
+    public function setDummyBoolean(?bool $dummyBoolean)
     {
         $this->dummyBoolean = $dummyBoolean;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyCarColor.php b/tests/Fixtures/TestBundle/Document/DummyCarColor.php
index efa4fb9bf0d..5fe8680ca3b 100644
--- a/tests/Fixtures/TestBundle/Document/DummyCarColor.php
+++ b/tests/Fixtures/TestBundle/Document/DummyCarColor.php
@@ -57,10 +57,7 @@ public function getId()
         return $this->id;
     }
 
-    /**
-     * @return DummyCar|null
-     */
-    public function getCar()
+    public function getCar(): ?DummyCar
     {
         return $this->car;
     }
@@ -75,10 +72,7 @@ public function setCar(DummyCar $car)
         return $this;
     }
 
-    /**
-     * @return string
-     */
-    public function getProp()
+    public function getProp(): string
     {
         return $this->prop;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyCustomMutation.php b/tests/Fixtures/TestBundle/Document/DummyCustomMutation.php
index 22cee9776c4..c0657c7c79f 100644
--- a/tests/Fixtures/TestBundle/Document/DummyCustomMutation.php
+++ b/tests/Fixtures/TestBundle/Document/DummyCustomMutation.php
@@ -58,21 +58,21 @@
 class DummyCustomMutation
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Field(type="int")
      */
     private $operandA;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @Groups({"sum"})
      * @ODM\Field(type="int", nullable=true)
@@ -80,19 +80,19 @@ class DummyCustomMutation
     private $operandB;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @Groups({"result"})
      * @ODM\Field(type="int", nullable=true)
      */
     private $result;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getOperandA(): int
+    public function getOperandA(): ?int
     {
         return $this->operandA;
     }
@@ -102,7 +102,7 @@ public function setOperandA(int $operandA): void
         $this->operandA = $operandA;
     }
 
-    public function getOperandB(): int
+    public function getOperandB(): ?int
     {
         return $this->operandB;
     }
@@ -112,7 +112,7 @@ public function setOperandB(int $operandB): void
         $this->operandB = $operandB;
     }
 
-    public function getResult(): int
+    public function getResult(): ?int
     {
         return $this->result;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyDate.php b/tests/Fixtures/TestBundle/Document/DummyDate.php
index dbeaabb2f88..4f3f56b1815 100644
--- a/tests/Fixtures/TestBundle/Document/DummyDate.php
+++ b/tests/Fixtures/TestBundle/Document/DummyDate.php
@@ -40,35 +40,35 @@
 class DummyDate
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var \DateTime The dummy date
+     * @var \DateTime|null The dummy date
      *
      * @ODM\Field(type="date")
      */
     public $dummyDate;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ODM\Field(type="date")
      */
     public $dateIncludeNullAfter;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ODM\Field(type="date")
      */
     public $dateIncludeNullBefore;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ODM\Field(type="date")
      */
@@ -76,10 +76,8 @@ class DummyDate
 
     /**
      * Get id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyDifferentGraphQlSerializationGroup.php b/tests/Fixtures/TestBundle/Document/DummyDifferentGraphQlSerializationGroup.php
index 06095dacb1c..52058188523 100644
--- a/tests/Fixtures/TestBundle/Document/DummyDifferentGraphQlSerializationGroup.php
+++ b/tests/Fixtures/TestBundle/Document/DummyDifferentGraphQlSerializationGroup.php
@@ -33,7 +33,7 @@
 class DummyDifferentGraphQlSerializationGroup
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int", nullable=true)
      * @Groups({"item_query", "collection_query"})
@@ -41,7 +41,7 @@ class DummyDifferentGraphQlSerializationGroup
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field(type="string")
      * @Groups({"item_query", "collection_query"})
@@ -49,19 +49,19 @@ class DummyDifferentGraphQlSerializationGroup
     private $name;
 
     /**
-     * @var string The dummy title
+     * @var string|null The dummy title
      *
      * @ODM\Field(nullable=true)
      * @Groups({"item_query"})
      */
     private $title;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
@@ -71,7 +71,7 @@ public function setName(string $name): void
         $this->name = $name;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyEntityWithConstructor.php b/tests/Fixtures/TestBundle/Document/DummyEntityWithConstructor.php
index 8a7b01358f4..5afcd4d8c2e 100644
--- a/tests/Fixtures/TestBundle/Document/DummyEntityWithConstructor.php
+++ b/tests/Fixtures/TestBundle/Document/DummyEntityWithConstructor.php
@@ -35,7 +35,7 @@
 class DummyEntityWithConstructor
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
@@ -56,7 +56,7 @@ class DummyEntityWithConstructor
     private $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      * @Groups({"put"})
@@ -78,7 +78,7 @@ public function __construct(string $foo, string $bar, array $items)
         $this->items = $items;
     }
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -101,10 +101,7 @@ public function getItems(): array
         return $this->items;
     }
 
-    /**
-     * @return string
-     */
-    public function getBaz()
+    public function getBaz(): ?string
     {
         return $this->baz;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyFriend.php b/tests/Fixtures/TestBundle/Document/DummyFriend.php
index b796747c6b0..a2422bc99b6 100644
--- a/tests/Fixtures/TestBundle/Document/DummyFriend.php
+++ b/tests/Fixtures/TestBundle/Document/DummyFriend.php
@@ -31,14 +31,14 @@
 class DummyFriend
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field(type="string")
      * @Assert\NotBlank
@@ -49,10 +49,8 @@ class DummyFriend
 
     /**
      * Get id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -69,10 +67,8 @@ public function setId($id)
 
     /**
      * Get name.
-     *
-     * @return string
      */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
@@ -82,7 +78,7 @@ public function getName()
      *
      * @param string $name the value to set
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyGroup.php b/tests/Fixtures/TestBundle/Document/DummyGroup.php
index e4ce58b0192..ccb0fcfcec3 100644
--- a/tests/Fixtures/TestBundle/Document/DummyGroup.php
+++ b/tests/Fixtures/TestBundle/Document/DummyGroup.php
@@ -50,7 +50,7 @@
 class DummyGroup
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      *
@@ -59,7 +59,7 @@ class DummyGroup
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -68,7 +68,7 @@ class DummyGroup
     public $foo;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -77,7 +77,7 @@ class DummyGroup
     public $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -86,7 +86,7 @@ class DummyGroup
     public $baz;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -94,10 +94,7 @@ class DummyGroup
      */
     public $qux;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyProduct.php b/tests/Fixtures/TestBundle/Document/DummyProduct.php
index e770bb4e8cd..b544f687852 100644
--- a/tests/Fixtures/TestBundle/Document/DummyProduct.php
+++ b/tests/Fixtures/TestBundle/Document/DummyProduct.php
@@ -107,7 +107,7 @@ public function getRelatedProducts(): Collection
         return $this->relatedProducts;
     }
 
-    public function setRelatedProducts(Collection $relatedProducts)
+    public function setRelatedProducts(iterable $relatedProducts): void
     {
         $this->relatedProducts = $relatedProducts;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyProperty.php b/tests/Fixtures/TestBundle/Document/DummyProperty.php
index a1f6efdd286..79cdda158b6 100644
--- a/tests/Fixtures/TestBundle/Document/DummyProperty.php
+++ b/tests/Fixtures/TestBundle/Document/DummyProperty.php
@@ -48,7 +48,7 @@
 class DummyProperty
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      *
@@ -57,7 +57,7 @@ class DummyProperty
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -66,7 +66,7 @@ class DummyProperty
     public $foo;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -75,7 +75,7 @@ class DummyProperty
     public $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -84,7 +84,7 @@ class DummyProperty
     public $baz;
 
     /**
-     * @var DummyGroup
+     * @var DummyGroup|null
      *
      * @ODM\ReferenceOne(targetDocument=DummyGroup::class, cascade={"persist"}, nullable=true)
      *
@@ -93,7 +93,7 @@ class DummyProperty
     public $group;
 
     /**
-     * @var DummyGroup[]
+     * @var DummyGroup[]|null
      *
      * @ODM\ReferenceMany(targetDocument=DummyGroup::class, cascade={"persist"})
      * @Groups({"dummy_read", "dummy_graphql_read", "dummy_write"})
@@ -101,7 +101,7 @@ class DummyProperty
     public $groups;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(nullable=true)
      *
@@ -109,10 +109,7 @@ class DummyProperty
      */
     public $nameConverted;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyTableInheritance.php b/tests/Fixtures/TestBundle/Document/DummyTableInheritance.php
index 6fad970c1ae..fa717021e1e 100644
--- a/tests/Fixtures/TestBundle/Document/DummyTableInheritance.php
+++ b/tests/Fixtures/TestBundle/Document/DummyTableInheritance.php
@@ -32,7 +32,7 @@
 class DummyTableInheritance
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      *
@@ -41,7 +41,7 @@ class DummyTableInheritance
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field
      *
@@ -50,39 +50,33 @@ class DummyTableInheritance
     private $name;
 
     /**
-     * @var DummyTableInheritanceRelated
+     * @var DummyTableInheritanceRelated|null
      *
      * @ODM\ReferenceOne(targetDocument=DummyTableInheritanceRelated::class, inversedBy="children")
      */
     private $parent;
 
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    public function setName($name)
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
 
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return DummyTableInheritanceRelated
-     */
-    public function getParent()
+    public function getParent(): ?DummyTableInheritanceRelated
     {
         return $this->parent;
     }
 
-    /**
-     * @return $this
-     */
-    public function setParent(DummyTableInheritanceRelated $parent)
+    public function setParent(DummyTableInheritanceRelated $parent): self
     {
         $this->parent = $parent;
 
diff --git a/tests/Fixtures/TestBundle/Document/DummyTableInheritanceRelated.php b/tests/Fixtures/TestBundle/Document/DummyTableInheritanceRelated.php
index a75cfd78e38..6390f407619 100644
--- a/tests/Fixtures/TestBundle/Document/DummyTableInheritanceRelated.php
+++ b/tests/Fixtures/TestBundle/Document/DummyTableInheritanceRelated.php
@@ -15,6 +15,7 @@
 
 use ApiPlatform\Core\Annotation\ApiResource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
 use Symfony\Component\Serializer\Annotation\Groups;
 
@@ -39,7 +40,7 @@ class DummyTableInheritanceRelated
     private $id;
 
     /**
-     * @var ArrayCollection Related children
+     * @var Collection Related children
      *
      * @ODM\ReferenceMany(targetDocument=DummyTableInheritance::class, mappedBy="parent")
      *
@@ -57,10 +58,7 @@ public function getId()
         return $this->id;
     }
 
-    /**
-     * @return ArrayCollection
-     */
-    public function getChildren()
+    public function getChildren(): Collection
     {
         return $this->children;
     }
diff --git a/tests/Fixtures/TestBundle/Document/DummyValidation.php b/tests/Fixtures/TestBundle/Document/DummyValidation.php
index 47bcc320211..105c9df126e 100644
--- a/tests/Fixtures/TestBundle/Document/DummyValidation.php
+++ b/tests/Fixtures/TestBundle/Document/DummyValidation.php
@@ -31,7 +31,7 @@
 class DummyValidation
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
@@ -54,83 +54,62 @@ class DummyValidation
     private $title;
 
     /**
-     * @var string The dummy code
+     * @var string|null The dummy code
      * @ODM\Field
      */
     private $code;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return DummyValidation
-     */
-    public function setId(int $id)
+    public function setId(int $id): self
     {
         $this->id = $id;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
     /**
      * @param string|null $name
-     *
-     * @return DummyValidation
      */
-    public function setName($name)
+    public function setName($name): self
     {
         $this->name = $name;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getTitle()
+    public function getTitle(): ?string
     {
         return $this->title;
     }
 
     /**
      * @param string|null $title
-     *
-     * @return DummyValidation
      */
-    public function setTitle($title)
+    public function setTitle($title): self
     {
         $this->title = $title;
 
         return $this;
     }
 
-    /**
-     * @return string
-     */
-    public function getCode()
+    public function getCode(): ?string
     {
         return $this->code;
     }
 
     /**
      * @param string $code
-     *
-     * @return DummyValidation
      */
-    public function setCode($code)
+    public function setCode($code): self
     {
         $this->code = $code;
 
diff --git a/tests/Fixtures/TestBundle/Document/EmbeddableDummy.php b/tests/Fixtures/TestBundle/Document/EmbeddableDummy.php
index eabe2acb647..50f0b81e2f2 100644
--- a/tests/Fixtures/TestBundle/Document/EmbeddableDummy.php
+++ b/tests/Fixtures/TestBundle/Document/EmbeddableDummy.php
@@ -28,7 +28,7 @@
 class EmbeddableDummy
 {
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field(type="string")
      * @Groups({"embed"})
@@ -36,14 +36,14 @@ class EmbeddableDummy
     private $dummyName;
 
     /**
-     * @var bool A dummy boolean
+     * @var bool|null A dummy boolean
      *
      * @ODM\Field(type="bool")
      */
     public $dummyBoolean;
 
     /**
-     * @var \DateTime A dummy date
+     * @var \DateTime|null A dummy date
      *
      * @ODM\Field(type="date")
      * @Assert\DateTime
@@ -51,14 +51,14 @@ class EmbeddableDummy
     public $dummyDate;
 
     /**
-     * @var string A dummy float
+     * @var float|null A dummy float
      *
      * @ODM\Field(type="float")
      */
     public $dummyFloat;
 
     /**
-     * @var string A dummy price
+     * @var float|null A dummy price
      *
      * @ODM\Field(type="float")
      */
@@ -70,7 +70,7 @@ class EmbeddableDummy
      */
     protected $symfony;
 
-    public static function staticMethod()
+    public static function staticMethod(): void
     {
     }
 
@@ -78,77 +78,62 @@ public function __construct()
     {
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyName()
+    public function getDummyName(): ?string
     {
         return $this->dummyName;
     }
 
-    public function setDummyName(string $dummyName)
+    public function setDummyName(string $dummyName): void
     {
         $this->dummyName = $dummyName;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
 
-    public function setDummyBoolean(bool $dummyBoolean)
+    public function setDummyBoolean(bool $dummyBoolean): void
     {
         $this->dummyBoolean = $dummyBoolean;
     }
 
-    /**
-     * @return \DateTime
-     */
-    public function getDummyDate()
+    public function getDummyDate(): ?\DateTime
     {
         return $this->dummyDate;
     }
 
-    public function setDummyDate(\DateTime $dummyDate)
+    public function setDummyDate(\DateTime $dummyDate): void
     {
         $this->dummyDate = $dummyDate;
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyFloat()
+    public function getDummyFloat(): ?float
     {
         return $this->dummyFloat;
     }
 
-    public function setDummyFloat(string $dummyFloat)
+    public function setDummyFloat(float $dummyFloat): void
     {
         $this->dummyFloat = $dummyFloat;
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyPrice()
+    public function getDummyPrice(): ?float
     {
         return $this->dummyPrice;
     }
 
-    public function setDummyPrice(string $dummyPrice)
+    public function setDummyPrice(float $dummyPrice): void
     {
         $this->dummyPrice = $dummyPrice;
     }
 
-    public function getSymfony()
+    public function getSymfony(): ?string
     {
         return $this->symfony;
     }
 
-    public function setSymfony($symfony)
+    public function setSymfony(string $symfony): void
     {
         $this->symfony = $symfony;
     }
diff --git a/tests/Fixtures/TestBundle/Document/EmbeddedDummy.php b/tests/Fixtures/TestBundle/Document/EmbeddedDummy.php
index dcba6fdc48d..6d29bcc28f0 100644
--- a/tests/Fixtures/TestBundle/Document/EmbeddedDummy.php
+++ b/tests/Fixtures/TestBundle/Document/EmbeddedDummy.php
@@ -33,14 +33,14 @@
 class EmbeddedDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field(type="string")
      * @Groups({"embed"})
@@ -48,7 +48,7 @@ class EmbeddedDummy
     private $name;
 
     /**
-     * @var \DateTime A dummy date
+     * @var \DateTime|null A dummy date
      *
      * @ODM\Field(type="date")
      * @Assert\DateTime
@@ -64,13 +64,13 @@ class EmbeddedDummy
     public $embeddedDummy;
 
     /**
-     * @var RelatedDummy A related dummy
+     * @var RelatedDummy|null A related dummy
      *
      * @ODM\ReferenceOne(targetDocument=RelatedDummy::class, storeAs="id")
      */
     public $relatedDummy;
 
-    public static function staticMethod()
+    public static function staticMethod(): void
     {
     }
 
@@ -79,17 +79,17 @@ public function __construct()
         $this->embeddedDummy = new EmbeddableDummy();
     }
 
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    public function setName(string $name)
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
@@ -99,33 +99,27 @@ public function getEmbeddedDummy(): EmbeddableDummy
         return $this->embeddedDummy;
     }
 
-    public function setEmbeddedDummy(EmbeddableDummy $embeddedDummy)
+    public function setEmbeddedDummy(EmbeddableDummy $embeddedDummy): void
     {
         $this->embeddedDummy = $embeddedDummy;
     }
 
-    /**
-     * @return \DateTime
-     */
-    public function getDummyDate()
+    public function getDummyDate(): ?\DateTime
     {
         return $this->dummyDate;
     }
 
-    public function setDummyDate(\DateTime $dummyDate)
+    public function setDummyDate(\DateTime $dummyDate): void
     {
         $this->dummyDate = $dummyDate;
     }
 
-    /**
-     * @return RelatedDummy
-     */
-    public function getRelatedDummy()
+    public function getRelatedDummy(): ?RelatedDummy
     {
         return $this->relatedDummy;
     }
 
-    public function setRelatedDummy(RelatedDummy $relatedDummy)
+    public function setRelatedDummy(RelatedDummy $relatedDummy): void
     {
         $this->relatedDummy = $relatedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Field.php b/tests/Fixtures/TestBundle/Document/Field.php
index 2e7f59c58ce..647e64e0289 100644
--- a/tests/Fixtures/TestBundle/Document/Field.php
+++ b/tests/Fixtures/TestBundle/Document/Field.php
@@ -63,7 +63,7 @@ public function setContent(?Content $content): void
         $this->content = $content;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
@@ -73,7 +73,7 @@ public function setName(string $name): void
         $this->name = $name;
     }
 
-    public function getValue(): string
+    public function getValue(): ?string
     {
         return $this->value;
     }
@@ -85,7 +85,10 @@ public function setValue(string $value): void
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return [
diff --git a/tests/Fixtures/TestBundle/Document/FourthLevel.php b/tests/Fixtures/TestBundle/Document/FourthLevel.php
index 8f51d9c9a83..f78dc4a9fac 100644
--- a/tests/Fixtures/TestBundle/Document/FourthLevel.php
+++ b/tests/Fixtures/TestBundle/Document/FourthLevel.php
@@ -28,14 +28,14 @@
 class FourthLevel
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Field(type="int")
      * @Groups({"barcelona", "chicago"})
@@ -47,26 +47,17 @@ class FourthLevel
      */
     public $badThirdLevel;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return int
-     */
-    public function getLevel()
+    public function getLevel(): ?int
     {
         return $this->level;
     }
 
-    /**
-     * @param int $level
-     */
-    public function setLevel($level)
+    public function setLevel(int $level)
     {
         $this->level = $level;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Greeting.php b/tests/Fixtures/TestBundle/Document/Greeting.php
index ada87385e8d..9c955096012 100644
--- a/tests/Fixtures/TestBundle/Document/Greeting.php
+++ b/tests/Fixtures/TestBundle/Document/Greeting.php
@@ -42,7 +42,7 @@ class Greeting
      */
     public $recipient;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Document/IriOnlyDummy.php b/tests/Fixtures/TestBundle/Document/IriOnlyDummy.php
index a4c1ec11ce6..7e5a99860aa 100644
--- a/tests/Fixtures/TestBundle/Document/IriOnlyDummy.php
+++ b/tests/Fixtures/TestBundle/Document/IriOnlyDummy.php
@@ -32,25 +32,25 @@
 class IriOnlyDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(type="string")
      */
     private $foo;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getFoo(): string
+    public function getFoo(): ?string
     {
         return $this->foo;
     }
diff --git a/tests/Fixtures/TestBundle/Document/LegacySecuredDummy.php b/tests/Fixtures/TestBundle/Document/LegacySecuredDummy.php
index b2d1a9c81ff..9b7f8cf308b 100644
--- a/tests/Fixtures/TestBundle/Document/LegacySecuredDummy.php
+++ b/tests/Fixtures/TestBundle/Document/LegacySecuredDummy.php
@@ -44,14 +44,14 @@
 class LegacySecuredDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var string The title
+     * @var string|null The title
      *
      * @ODM\Field
      * @Assert\NotBlank
@@ -66,19 +66,19 @@ class LegacySecuredDummy
     private $description = '';
 
     /**
-     * @var string The owner
+     * @var string|null The owner
      *
      * @ODM\Field
      * @Assert\NotBlank
      */
     private $owner;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
@@ -98,7 +98,7 @@ public function setDescription(string $description)
         $this->description = $description;
     }
 
-    public function getOwner(): string
+    public function getOwner(): ?string
     {
         return $this->owner;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Payment.php b/tests/Fixtures/TestBundle/Document/Payment.php
index 13e7c98d1f9..b96a5fa3133 100644
--- a/tests/Fixtures/TestBundle/Document/Payment.php
+++ b/tests/Fixtures/TestBundle/Document/Payment.php
@@ -42,7 +42,7 @@ class Payment
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      */
     private $amount;
 
@@ -61,7 +61,7 @@ public function getId(): ?int
         return $this->id;
     }
 
-    public function getAmount(): string
+    public function getAmount(): ?string
     {
         return $this->amount;
     }
diff --git a/tests/Fixtures/TestBundle/Document/Question.php b/tests/Fixtures/TestBundle/Document/Question.php
index 1e218cb907e..cc1796b55d3 100644
--- a/tests/Fixtures/TestBundle/Document/Question.php
+++ b/tests/Fixtures/TestBundle/Document/Question.php
@@ -43,10 +43,8 @@ class Question
      * Set content.
      *
      * @param string $content
-     *
-     * @return Question
      */
-    public function setContent($content)
+    public function setContent($content): self
     {
         $this->content = $content;
 
@@ -55,32 +53,24 @@ public function setContent($content)
 
     /**
      * Get content.
-     *
-     * @return string
      */
-    public function getContent()
+    public function getContent(): string
     {
         return $this->content;
     }
 
     /**
      * Get id.
-     *
-     * @return string
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Set answer.
-     *
-     * @param Answer $answer
-     *
-     * @return Question
      */
-    public function setAnswer(Answer $answer = null)
+    public function setAnswer(Answer $answer = null): self
     {
         $this->answer = $answer;
 
@@ -89,10 +79,8 @@ public function setAnswer(Answer $answer = null)
 
     /**
      * Get answer.
-     *
-     * @return Answer
      */
-    public function getAnswer()
+    public function getAnswer(): ?Answer
     {
         return $this->answer;
     }
diff --git a/tests/Fixtures/TestBundle/Document/RelatedDummy.php b/tests/Fixtures/TestBundle/Document/RelatedDummy.php
index e4fb067d2b4..9666b556ea6 100644
--- a/tests/Fixtures/TestBundle/Document/RelatedDummy.php
+++ b/tests/Fixtures/TestBundle/Document/RelatedDummy.php
@@ -17,6 +17,7 @@
 use ApiPlatform\Core\Annotation\ApiResource;
 use ApiPlatform\Core\Annotation\ApiSubresource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -139,10 +140,7 @@ public function getDummyDate()
         return $this->dummyDate;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
@@ -155,10 +153,7 @@ public function setDummyBoolean($dummyBoolean)
         $this->dummyBoolean = $dummyBoolean;
     }
 
-    /**
-     * @return ThirdLevel|null
-     */
-    public function getThirdLevel()
+    public function getThirdLevel(): ?ThirdLevel
     {
         return $this->thirdLevel;
     }
@@ -170,10 +165,8 @@ public function setThirdLevel(ThirdLevel $thirdLevel = null)
 
     /**
      * Get relatedToDummyFriend.
-     *
-     * @return RelatedToDummyFriend
      */
-    public function getRelatedToDummyFriend()
+    public function getRelatedToDummyFriend(): Collection
     {
         return $this->relatedToDummyFriend;
     }
@@ -188,10 +181,7 @@ public function addRelatedToDummyFriend(RelatedToDummyFriend $relatedToDummyFrie
         $this->relatedToDummyFriend->add($relatedToDummyFriend);
     }
 
-    /**
-     * @return EmbeddableDummy
-     */
-    public function getEmbeddedDummy()
+    public function getEmbeddedDummy(): EmbeddableDummy
     {
         return $this->embeddedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/RelatedNormalizedDummy.php b/tests/Fixtures/TestBundle/Document/RelatedNormalizedDummy.php
index e5870896d1f..4300db6cef9 100644
--- a/tests/Fixtures/TestBundle/Document/RelatedNormalizedDummy.php
+++ b/tests/Fixtures/TestBundle/Document/RelatedNormalizedDummy.php
@@ -16,6 +16,7 @@
 use ApiPlatform\Core\Annotation\ApiProperty;
 use ApiPlatform\Core\Annotation\ApiResource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -34,7 +35,7 @@
 class RelatedNormalizedDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      * @Groups({"related_output", "related_input"})
@@ -42,7 +43,7 @@ class RelatedNormalizedDummy
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ODM\Field
      * @Assert\NotBlank
@@ -52,7 +53,7 @@ class RelatedNormalizedDummy
     private $name;
 
     /**
-     * @var ArrayCollection Several Normalized dummies
+     * @var iterable Several Normalized dummies
      *
      * @ODM\ReferenceMany(targetDocument=CustomNormalizedDummy::class)
      * @Groups({"related_output", "related_input"})
@@ -64,7 +65,7 @@ public function __construct()
         $this->customNormalizedDummy = new ArrayCollection();
     }
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -77,23 +78,17 @@ public function setName($name)
         $this->name = $name;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    /**
-     * @return ArrayCollection
-     */
-    public function getCustomNormalizedDummy()
+    public function getCustomNormalizedDummy(): Collection
     {
         return $this->customNormalizedDummy;
     }
 
-    /**
-     * @param ArrayCollection $customNormalizedDummy
-     */
-    public function setCustomNormalizedDummy($customNormalizedDummy)
+    public function setCustomNormalizedDummy(iterable $customNormalizedDummy): void
     {
         $this->customNormalizedDummy = $customNormalizedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/RelatedOwnedDummy.php b/tests/Fixtures/TestBundle/Document/RelatedOwnedDummy.php
index 20dbd0f0629..ad5712b805d 100644
--- a/tests/Fixtures/TestBundle/Document/RelatedOwnedDummy.php
+++ b/tests/Fixtures/TestBundle/Document/RelatedOwnedDummy.php
@@ -34,14 +34,14 @@ class RelatedOwnedDummy
     private $id;
 
     /**
-     * @var string A name
+     * @var string|null A name
      *
      * @ODM\Field(type="string")
      */
     public $name;
 
     /**
-     * @var Dummy
+     * @var Dummy|null
      *
      * @ODM\ReferenceOne(targetDocument=Dummy::class, cascade={"persist"}, inversedBy="relatedOwnedDummy", storeAs="id")
      * @ApiSubresource
@@ -70,10 +70,8 @@ public function getName()
 
     /**
      * Get owning dummy.
-     *
-     * @return Dummy
      */
-    public function getOwningDummy()
+    public function getOwningDummy(): ?Dummy
     {
         return $this->owningDummy;
     }
@@ -83,7 +81,7 @@ public function getOwningDummy()
      *
      * @param Dummy $owningDummy the value to set
      */
-    public function setOwningDummy(Dummy $owningDummy)
+    public function setOwningDummy(Dummy $owningDummy): void
     {
         $this->owningDummy = $owningDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/RelatedOwningDummy.php b/tests/Fixtures/TestBundle/Document/RelatedOwningDummy.php
index 944a1b1fdc8..dbfaf81adc3 100644
--- a/tests/Fixtures/TestBundle/Document/RelatedOwningDummy.php
+++ b/tests/Fixtures/TestBundle/Document/RelatedOwningDummy.php
@@ -70,10 +70,8 @@ public function getName()
 
     /**
      * Get owned dummy.
-     *
-     * @return Dummy
      */
-    public function getOwnedDummy()
+    public function getOwnedDummy(): Dummy
     {
         return $this->ownedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/RelatedToDummyFriend.php b/tests/Fixtures/TestBundle/Document/RelatedToDummyFriend.php
index a4554978817..048c846be38 100644
--- a/tests/Fixtures/TestBundle/Document/RelatedToDummyFriend.php
+++ b/tests/Fixtures/TestBundle/Document/RelatedToDummyFriend.php
@@ -83,10 +83,7 @@ public function getName()
         return $this->name;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getDescription()
+    public function getDescription(): ?string
     {
         return $this->description;
     }
@@ -101,10 +98,8 @@ public function setDescription($description)
 
     /**
      * Gets dummyFriend.
-     *
-     * @return DummyFriend
      */
-    public function getDummyFriend()
+    public function getDummyFriend(): DummyFriend
     {
         return $this->dummyFriend;
     }
@@ -121,10 +116,8 @@ public function setDummyFriend(DummyFriend $dummyFriend)
 
     /**
      * Gets relatedDummy.
-     *
-     * @return RelatedDummy
      */
-    public function getRelatedDummy()
+    public function getRelatedDummy(): RelatedDummy
     {
         return $this->relatedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/SecuredDummy.php b/tests/Fixtures/TestBundle/Document/SecuredDummy.php
index 58c787110ca..562c7464ca7 100644
--- a/tests/Fixtures/TestBundle/Document/SecuredDummy.php
+++ b/tests/Fixtures/TestBundle/Document/SecuredDummy.php
@@ -52,14 +52,14 @@
 class SecuredDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     private $id;
 
     /**
-     * @var string The title
+     * @var string|null The title
      *
      * @ODM\Field
      * @Assert\NotBlank
@@ -82,19 +82,19 @@ class SecuredDummy
     private $adminOnlyProperty = '';
 
     /**
-     * @var string The owner
+     * @var string|null The owner
      *
      * @ODM\Field
      * @Assert\NotBlank
      */
     private $owner;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
@@ -124,7 +124,7 @@ public function setAdminOnlyProperty(?string $adminOnlyProperty)
         $this->adminOnlyProperty = $adminOnlyProperty;
     }
 
-    public function getOwner(): string
+    public function getOwner(): ?string
     {
         return $this->owner;
     }
diff --git a/tests/Fixtures/TestBundle/Document/SlugChildDummy.php b/tests/Fixtures/TestBundle/Document/SlugChildDummy.php
index 3e993c1ede4..52d9d91d506 100644
--- a/tests/Fixtures/TestBundle/Document/SlugChildDummy.php
+++ b/tests/Fixtures/TestBundle/Document/SlugChildDummy.php
@@ -49,18 +49,12 @@ class SlugChildDummy
      */
     private $parentDummy;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): string
     {
         return $this->slug;
     }
@@ -70,10 +64,7 @@ public function setSlug(string $slug)
         $this->slug = $slug;
     }
 
-    /**
-     * @return SlugParentDummy
-     */
-    public function getParentDummy()
+    public function getParentDummy(): SlugParentDummy
     {
         return $this->parentDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Document/SlugParentDummy.php b/tests/Fixtures/TestBundle/Document/SlugParentDummy.php
index 216957e1328..0d69cf6764a 100644
--- a/tests/Fixtures/TestBundle/Document/SlugParentDummy.php
+++ b/tests/Fixtures/TestBundle/Document/SlugParentDummy.php
@@ -29,7 +29,7 @@
 class SlugParentDummy
 {
     /**
-     * @var int The database identifier
+     * @var int|null The database identifier
      *
      * @ApiProperty(identifier=false)
      *
@@ -38,7 +38,7 @@ class SlugParentDummy
     private $id;
 
     /**
-     * @var string The slug used a API identifier
+     * @var string|null The slug used a API identifier
      *
      * @ApiProperty(identifier=true)
      *
@@ -58,26 +58,17 @@ public function __construct()
         $this->childDummies = new ArrayCollection();
     }
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): ?string
     {
         return $this->slug;
     }
 
-    /**
-     * @param string $slug
-     */
-    public function setSlug($slug)
+    public function setSlug(string $slug)
     {
         $this->slug = $slug;
     }
diff --git a/tests/Fixtures/TestBundle/Document/ThirdLevel.php b/tests/Fixtures/TestBundle/Document/ThirdLevel.php
index 40a590914d3..1be2c118de3 100644
--- a/tests/Fixtures/TestBundle/Document/ThirdLevel.php
+++ b/tests/Fixtures/TestBundle/Document/ThirdLevel.php
@@ -30,7 +30,7 @@
 class ThirdLevel
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
@@ -63,50 +63,32 @@ class ThirdLevel
      */
     public $badFourthLevel;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return int
-     */
-    public function getLevel()
+    public function getLevel(): int
     {
         return $this->level;
     }
 
-    /**
-     * @param int $level
-     */
-    public function setLevel($level)
+    public function setLevel(int $level)
     {
         $this->level = $level;
     }
 
-    /**
-     * @return bool
-     */
-    public function isTest()
+    public function isTest(): bool
     {
         return $this->test;
     }
 
-    /**
-     * @param bool $test
-     */
-    public function setTest($test)
+    public function setTest(bool $test)
     {
         $this->test = $test;
     }
 
-    /**
-     * @return FourthLevel|null
-     */
-    public function getFourthLevel()
+    public function getFourthLevel(): ?FourthLevel
     {
         return $this->fourthLevel;
     }
diff --git a/tests/Fixtures/TestBundle/Document/User.php b/tests/Fixtures/TestBundle/Document/User.php
index 4a19447c268..d3a95a220ba 100644
--- a/tests/Fixtures/TestBundle/Document/User.php
+++ b/tests/Fixtures/TestBundle/Document/User.php
@@ -61,21 +61,21 @@
 class User extends AbstractSecurityUser
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int")
      */
     protected $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @Groups({"user"})
      */
     protected $email;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ODM\Field(type="string", nullable=true)
      * @Groups({"user"})
@@ -83,25 +83,25 @@ class User extends AbstractSecurityUser
     protected $fullname;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @Groups({"user-write"})
      */
     protected $plainPassword;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @Groups({"user"})
      */
     protected $username;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getEmail(): string
+    public function getEmail(): ?string
     {
         return $this->email;
     }
@@ -121,22 +121,14 @@ public function setPlainPassword(string $plainPassword): void
         $this->plainPassword = $plainPassword;
     }
 
-    /**
-     * @param string|null $fullname
-     *
-     * @return $this
-     */
-    public function setFullname($fullname)
+    public function setFullname(?string $fullname): self
     {
         $this->fullname = $fullname;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getFullname()
+    public function getFullname(): ?string
     {
         return $this->fullname;
     }
@@ -161,7 +153,7 @@ public function getPassword(): ?string
         return null;
     }
 
-    public function getSalt()
+    public function getSalt(): ?string
     {
         return null;
     }
diff --git a/tests/Fixtures/TestBundle/Document/WithJsonDummy.php b/tests/Fixtures/TestBundle/Document/WithJsonDummy.php
index a0a82da40b8..6fead8905b9 100644
--- a/tests/Fixtures/TestBundle/Document/WithJsonDummy.php
+++ b/tests/Fixtures/TestBundle/Document/WithJsonDummy.php
@@ -23,7 +23,7 @@
 class WithJsonDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ODM\Id(strategy="INCREMENT", type="int", nullable=true)
      */
@@ -36,7 +36,7 @@ class WithJsonDummy
      */
     public $json;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Answer.php b/tests/Fixtures/TestBundle/Entity/Answer.php
index b68da8ff8f7..6229d07961c 100644
--- a/tests/Fixtures/TestBundle/Entity/Answer.php
+++ b/tests/Fixtures/TestBundle/Entity/Answer.php
@@ -16,6 +16,7 @@
 use ApiPlatform\Core\Annotation\ApiResource;
 use ApiPlatform\Core\Annotation\ApiSubresource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation as Serializer;
 
@@ -63,10 +64,8 @@ public function __construct()
 
     /**
      * Get id.
-     *
-     * @return string
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -75,10 +74,8 @@ public function getId()
      * Set content.
      *
      * @param string $content
-     *
-     * @return Answer
      */
-    public function setContent($content)
+    public function setContent($content): self
     {
         $this->content = $content;
 
@@ -87,10 +84,8 @@ public function setContent($content)
 
     /**
      * Get content.
-     *
-     * @return string
      */
-    public function getContent()
+    public function getContent(): ?string
     {
         return $this->content;
     }
@@ -99,10 +94,8 @@ public function getContent()
      * Set question.
      *
      * @param Question $question
-     *
-     * @return Answer
      */
-    public function setQuestion(Question $question = null)
+    public function setQuestion(Question $question = null): self
     {
         $this->question = $question;
 
@@ -111,20 +104,16 @@ public function setQuestion(Question $question = null)
 
     /**
      * Get question.
-     *
-     * @return Question
      */
-    public function getQuestion()
+    public function getQuestion(): ?Question
     {
         return $this->question;
     }
 
     /**
      * Get related question.
-     *
-     * @return ArrayCollection
      */
-    public function getRelatedQuestions()
+    public function getRelatedQuestions(): Collection
     {
         return $this->relatedQuestions;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CompositeItem.php b/tests/Fixtures/TestBundle/Entity/CompositeItem.php
index 1291bc03018..9c2ad306456 100644
--- a/tests/Fixtures/TestBundle/Entity/CompositeItem.php
+++ b/tests/Fixtures/TestBundle/Entity/CompositeItem.php
@@ -14,6 +14,7 @@
 namespace ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity;
 
 use ApiPlatform\Core\Annotation\ApiResource;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 
@@ -46,20 +47,16 @@ class CompositeItem
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets field1.
-     *
-     * @return string|null
      */
-    public function getField1()
+    public function getField1(): ?string
     {
         return $this->field1;
     }
@@ -76,15 +73,13 @@ public function setField1($field1 = null)
 
     /**
      * Gets compositeValues.
-     *
-     * @return CompositeRelation
      */
-    public function getCompositeValues()
+    public function getCompositeValues(): ?Collection
     {
         return $this->compositeValues;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return (string) $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CompositeLabel.php b/tests/Fixtures/TestBundle/Entity/CompositeLabel.php
index 88ee80d743d..399997ad7e8 100644
--- a/tests/Fixtures/TestBundle/Entity/CompositeLabel.php
+++ b/tests/Fixtures/TestBundle/Entity/CompositeLabel.php
@@ -40,20 +40,16 @@ class CompositeLabel
 
     /**
      * Gets id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
     /**
      * Gets value.
-     *
-     * @return string|null
      */
-    public function getValue()
+    public function getValue(): ?string
     {
         return $this->value;
     }
@@ -63,12 +59,12 @@ public function getValue()
      *
      * @param string|null $value the value to set
      */
-    public function setValue($value = null)
+    public function setValue(?string $value = null)
     {
         $this->value = $value;
     }
 
-    public function __toString()
+    public function __toString(): string
     {
         return (string) $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CompositePrimitiveItem.php b/tests/Fixtures/TestBundle/Entity/CompositePrimitiveItem.php
index a57b24100dc..e6bcd8a8fd4 100644
--- a/tests/Fixtures/TestBundle/Entity/CompositePrimitiveItem.php
+++ b/tests/Fixtures/TestBundle/Entity/CompositePrimitiveItem.php
@@ -49,20 +49,16 @@ public function __construct(string $name, int $year)
 
     /**
      * Gets name.
-     *
-     * @return string
      */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
 
     /**
      * Gets year.
-     *
-     * @return int
      */
-    public function getYear()
+    public function getYear(): int
     {
         return $this->year;
     }
@@ -77,10 +73,8 @@ public function setDescription(string $description)
 
     /**
      * Gets description.
-     *
-     * @return string
      */
-    public function getDescription()
+    public function getDescription(): string
     {
         return $this->description;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CompositeRelation.php b/tests/Fixtures/TestBundle/Entity/CompositeRelation.php
index 71dfee44f78..dcbc014c79f 100644
--- a/tests/Fixtures/TestBundle/Entity/CompositeRelation.php
+++ b/tests/Fixtures/TestBundle/Entity/CompositeRelation.php
@@ -49,10 +49,8 @@ class CompositeRelation
 
     /**
      * Gets value.
-     *
-     * @return string|null
      */
-    public function getValue()
+    public function getValue(): ?string
     {
         return $this->value;
     }
@@ -69,10 +67,8 @@ public function setValue($value = null)
 
     /**
      * Gets compositeItem.
-     *
-     * @return CompositeItem
      */
-    public function getCompositeItem()
+    public function getCompositeItem(): CompositeItem
     {
         return $this->compositeItem;
     }
@@ -89,10 +85,8 @@ public function setCompositeItem(CompositeItem $compositeItem)
 
     /**
      * Gets compositeLabel.
-     *
-     * @return CompositeLabel
      */
-    public function getCompositeLabel()
+    public function getCompositeLabel(): CompositeLabel
     {
         return $this->compositeLabel;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Content.php b/tests/Fixtures/TestBundle/Entity/Content.php
index 59389fda9f1..3b58ffd84ad 100644
--- a/tests/Fixtures/TestBundle/Entity/Content.php
+++ b/tests/Fixtures/TestBundle/Entity/Content.php
@@ -151,7 +151,10 @@ public function getStatus(): ContentStatus
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return [
diff --git a/tests/Fixtures/TestBundle/Entity/CustomActionDummy.php b/tests/Fixtures/TestBundle/Entity/CustomActionDummy.php
index 1ceb19c85dc..32991904454 100644
--- a/tests/Fixtures/TestBundle/Entity/CustomActionDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/CustomActionDummy.php
@@ -36,7 +36,7 @@
 class CustomActionDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -51,7 +51,7 @@ class CustomActionDummy
      */
     private $foo = '';
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -61,7 +61,7 @@ public function getFoo(): string
         return $this->foo;
     }
 
-    public function setFoo(string $foo)
+    public function setFoo(string $foo): void
     {
         $this->foo = $foo;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CustomIdentifierDummy.php b/tests/Fixtures/TestBundle/Entity/CustomIdentifierDummy.php
index f9d12bb5e27..e5788230f2a 100644
--- a/tests/Fixtures/TestBundle/Entity/CustomIdentifierDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/CustomIdentifierDummy.php
@@ -40,18 +40,12 @@ class CustomIdentifierDummy
      */
     private $name;
 
-    /**
-     * @return int
-     */
-    public function getCustomId()
+    public function getCustomId(): int
     {
         return $this->customId;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CustomNormalizedDummy.php b/tests/Fixtures/TestBundle/Entity/CustomNormalizedDummy.php
index 62b981ff61f..2ed51568894 100644
--- a/tests/Fixtures/TestBundle/Entity/CustomNormalizedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/CustomNormalizedDummy.php
@@ -33,7 +33,7 @@
 class CustomNormalizedDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -43,7 +43,7 @@ class CustomNormalizedDummy
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ORM\Column
      * @Assert\NotBlank
@@ -53,7 +53,7 @@ class CustomNormalizedDummy
     private $name;
 
     /**
-     * @var string The dummy name alias
+     * @var string|null The dummy name alias
      *
      * @ORM\Column(nullable=true)
      * @ApiProperty(iri="https://schema.org/alternateName")
@@ -61,58 +61,37 @@ class CustomNormalizedDummy
      */
     private $alias;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @param string $name
-     */
-    public function setName($name)
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    /**
-     * @return string
-     */
-    public function getAlias()
+    public function getAlias(): ?string
     {
         return $this->alias;
     }
 
-    /**
-     * @param string $alias
-     */
-    public function setAlias($alias)
+    public function setAlias(string $alias): void
     {
         $this->alias = $alias;
     }
 
-    /**
-     * @return string
-     */
-    public function getPersonalizedAlias()
+    public function getPersonalizedAlias(): string
     {
         return $this->alias;
     }
 
-    /**
-     * @param string $value
-     */
-    public function setPersonalizedAlias($value)
+    public function setPersonalizedAlias(string $value): void
     {
         $this->alias = $value;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/CustomWritableIdentifierDummy.php b/tests/Fixtures/TestBundle/Entity/CustomWritableIdentifierDummy.php
index ede113cb776..86fa31da8cb 100644
--- a/tests/Fixtures/TestBundle/Entity/CustomWritableIdentifierDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/CustomWritableIdentifierDummy.php
@@ -47,18 +47,12 @@ public function setSlug($slug)
         $this->slug = $slug;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): string
     {
         return $this->slug;
     }
 
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): string
     {
         return $this->name;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Dummy.php b/tests/Fixtures/TestBundle/Entity/Dummy.php
index af81454acb1..408b9879712 100644
--- a/tests/Fixtures/TestBundle/Entity/Dummy.php
+++ b/tests/Fixtures/TestBundle/Entity/Dummy.php
@@ -313,10 +313,7 @@ public function setRelatedOwningDummy(RelatedOwningDummy $relatedOwningDummy)
         $this->relatedOwningDummy = $relatedOwningDummy;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyCarColor.php b/tests/Fixtures/TestBundle/Entity/DummyCarColor.php
index a9eaef13ded..f79aa482437 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyCarColor.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyCarColor.php
@@ -60,10 +60,7 @@ public function getId()
         return $this->id;
     }
 
-    /**
-     * @return DummyCar|null
-     */
-    public function getCar()
+    public function getCar(): ?DummyCar
     {
         return $this->car;
     }
@@ -78,10 +75,7 @@ public function setCar(DummyCar $car)
         return $this;
     }
 
-    /**
-     * @return string
-     */
-    public function getProp()
+    public function getProp(): string
     {
         return $this->prop;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyCustomMutation.php b/tests/Fixtures/TestBundle/Entity/DummyCustomMutation.php
index 99666e1a637..c8de0874812 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyCustomMutation.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyCustomMutation.php
@@ -58,7 +58,7 @@
 class DummyCustomMutation
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -67,14 +67,14 @@ class DummyCustomMutation
     private $id;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer", nullable=true)
      */
     private $operandA;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @Groups({"sum"})
      * @ORM\Column(type="integer", nullable=true)
@@ -82,19 +82,19 @@ class DummyCustomMutation
     private $operandB;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @Groups({"result"})
      * @ORM\Column(type="integer", nullable=true)
      */
     private $result;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getOperandA(): int
+    public function getOperandA(): ?int
     {
         return $this->operandA;
     }
@@ -104,7 +104,7 @@ public function setOperandA(int $operandA): void
         $this->operandA = $operandA;
     }
 
-    public function getOperandB(): int
+    public function getOperandB(): ?int
     {
         return $this->operandB;
     }
@@ -114,7 +114,7 @@ public function setOperandB(int $operandB): void
         $this->operandB = $operandB;
     }
 
-    public function getResult(): int
+    public function getResult(): ?int
     {
         return $this->result;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyDate.php b/tests/Fixtures/TestBundle/Entity/DummyDate.php
index 37fe8d5de12..4013eb4d574 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyDate.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyDate.php
@@ -39,7 +39,7 @@
 class DummyDate
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -48,28 +48,28 @@ class DummyDate
     private $id;
 
     /**
-     * @var \DateTime The dummy date
+     * @var \DateTime|null The dummy date
      *
      * @ORM\Column(type="date")
      */
     public $dummyDate;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ORM\Column(type="date", nullable=true)
      */
     public $dateIncludeNullAfter;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ORM\Column(type="date", nullable=true)
      */
     public $dateIncludeNullBefore;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      *
      * @ORM\Column(type="date", nullable=true)
      */
@@ -77,10 +77,8 @@ class DummyDate
 
     /**
      * Get id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyDifferentGraphQlSerializationGroup.php b/tests/Fixtures/TestBundle/Entity/DummyDifferentGraphQlSerializationGroup.php
index d54b21b3cf0..88fd2734e64 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyDifferentGraphQlSerializationGroup.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyDifferentGraphQlSerializationGroup.php
@@ -33,7 +33,7 @@
 class DummyDifferentGraphQlSerializationGroup
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer", nullable=true)
      * @ORM\Id
@@ -43,7 +43,7 @@ class DummyDifferentGraphQlSerializationGroup
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ORM\Column
      * @Groups({"item_query", "collection_query"})
@@ -51,19 +51,19 @@ class DummyDifferentGraphQlSerializationGroup
     private $name;
 
     /**
-     * @var string The dummy title
+     * @var string|null The dummy title
      *
      * @ORM\Column(nullable=true)
      * @Groups({"item_query"})
      */
     private $title;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
@@ -75,7 +75,7 @@ public function setName(string $name): self
         return $this;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyEntityWithConstructor.php b/tests/Fixtures/TestBundle/Entity/DummyEntityWithConstructor.php
index 04f4597cb71..1d5b70e1459 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyEntityWithConstructor.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyEntityWithConstructor.php
@@ -35,7 +35,7 @@
 class DummyEntityWithConstructor
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -58,7 +58,7 @@ class DummyEntityWithConstructor
     private $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      * @Groups({"put"})
@@ -80,7 +80,7 @@ public function __construct(string $foo, string $bar, array $items)
         $this->items = $items;
     }
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -103,15 +103,12 @@ public function getItems(): array
         return $this->items;
     }
 
-    /**
-     * @return string
-     */
-    public function getBaz()
+    public function getBaz(): ?string
     {
         return $this->baz;
     }
 
-    public function setBaz(string $baz)
+    public function setBaz(string $baz): void
     {
         $this->baz = $baz;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyFriend.php b/tests/Fixtures/TestBundle/Entity/DummyFriend.php
index 692259dcfb9..aa25f14b1e3 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyFriend.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyFriend.php
@@ -30,7 +30,7 @@
 class DummyFriend
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -39,7 +39,7 @@ class DummyFriend
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ORM\Column
      * @Assert\NotBlank
@@ -50,10 +50,8 @@ class DummyFriend
 
     /**
      * Get id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -63,17 +61,15 @@ public function getId()
      *
      * @param int $id the value to set
      */
-    public function setId($id)
+    public function setId(int $id): void
     {
         $this->id = $id;
     }
 
     /**
      * Get name.
-     *
-     * @return string
      */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
@@ -83,7 +79,7 @@ public function getName()
      *
      * @param string $name the value to set
      */
-    public function setName($name)
+    public function setName(string $name)
     {
         $this->name = $name;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyGroup.php b/tests/Fixtures/TestBundle/Entity/DummyGroup.php
index ab7367c9ab5..d3f9c6c99cd 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyGroup.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyGroup.php
@@ -49,7 +49,7 @@
 class DummyGroup
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Id
      * @ORM\Column(type="integer")
@@ -60,7 +60,7 @@ class DummyGroup
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -69,7 +69,7 @@ class DummyGroup
     public $foo;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -78,7 +78,7 @@ class DummyGroup
     public $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -87,7 +87,7 @@ class DummyGroup
     public $baz;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -95,10 +95,7 @@ class DummyGroup
      */
     public $qux;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyImmutableDate.php b/tests/Fixtures/TestBundle/Entity/DummyImmutableDate.php
index 252aa4e6aaa..8f013b63605 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyImmutableDate.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyImmutableDate.php
@@ -27,7 +27,7 @@
 class DummyImmutableDate
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -36,7 +36,7 @@ class DummyImmutableDate
     private $id;
 
     /**
-     * @var \DateTimeImmutable The dummy date
+     * @var \DateTimeImmutable|null The dummy date
      *
      * @ORM\Column(type="date_immutable")
      */
@@ -44,10 +44,8 @@ class DummyImmutableDate
 
     /**
      * Get id.
-     *
-     * @return int
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyProduct.php b/tests/Fixtures/TestBundle/Entity/DummyProduct.php
index 6c492322c71..df1ff7932af 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyProduct.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyProduct.php
@@ -109,7 +109,7 @@ public function getRelatedProducts(): Collection
         return $this->relatedProducts;
     }
 
-    public function setRelatedProducts(Collection $relatedProducts)
+    public function setRelatedProducts(iterable $relatedProducts)
     {
         $this->relatedProducts = $relatedProducts;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyProperty.php b/tests/Fixtures/TestBundle/Entity/DummyProperty.php
index b311f0a1538..ec4f37da383 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyProperty.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyProperty.php
@@ -48,7 +48,7 @@
 class DummyProperty
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Id
      * @ORM\Column(type="integer")
@@ -59,7 +59,7 @@ class DummyProperty
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -68,7 +68,7 @@ class DummyProperty
     public $foo;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -77,7 +77,7 @@ class DummyProperty
     public $bar;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -86,7 +86,7 @@ class DummyProperty
     public $baz;
 
     /**
-     * @var DummyGroup
+     * @var DummyGroup|null
      *
      * @ORM\ManyToOne(targetEntity=DummyGroup::class, cascade={"persist"})
      *
@@ -95,7 +95,7 @@ class DummyProperty
     public $group;
 
     /**
-     * @var DummyGroup[]
+     * @var DummyGroup[]|null
      *
      * @ORM\ManyToMany(targetEntity=DummyGroup::class, cascade={"persist"})
      * @Groups({"dummy_read", "dummy_graphql_read", "dummy_write"})
@@ -103,7 +103,7 @@ class DummyProperty
     public $groups;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(nullable=true)
      *
@@ -111,10 +111,7 @@ class DummyProperty
      */
     public $nameConverted;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyPropertyWithDefaultValue.php b/tests/Fixtures/TestBundle/Entity/DummyPropertyWithDefaultValue.php
index 2c7323165bd..5ab1296ab59 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyPropertyWithDefaultValue.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyPropertyWithDefaultValue.php
@@ -30,7 +30,7 @@
 class DummyPropertyWithDefaultValue
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Id
      * @ORM\Column(type="integer")
@@ -50,16 +50,13 @@ class DummyPropertyWithDefaultValue
     public $foo = 'foo';
 
     /**
-     * @var string A dummy with a Doctrine default options
+     * @var string|null A dummy with a Doctrine default options
      *
      * @ORM\Column(options={"default"="default value"})
      */
     public $dummyDefaultOption;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyTableInheritance.php b/tests/Fixtures/TestBundle/Entity/DummyTableInheritance.php
index 23b629d541d..3f3954d32f8 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyTableInheritance.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyTableInheritance.php
@@ -32,7 +32,7 @@
 class DummyTableInheritance
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -43,7 +43,7 @@ class DummyTableInheritance
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ORM\Column
      *
@@ -52,40 +52,34 @@ class DummyTableInheritance
     private $name;
 
     /**
-     * @var DummyTableInheritanceRelated
+     * @var DummyTableInheritanceRelated|null
      *
      * @ORM\ManyToOne(targetEntity="DummyTableInheritanceRelated", inversedBy="children")
      * @ORM\JoinColumn(nullable=true, onDelete="CASCADE")
      */
     private $parent;
 
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    public function setName($name)
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
 
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return DummyTableInheritanceRelated
-     */
-    public function getParent()
+    public function getParent(): ?DummyTableInheritanceRelated
     {
         return $this->parent;
     }
 
-    /**
-     * @return $this
-     */
-    public function setParent(DummyTableInheritanceRelated $parent)
+    public function setParent(?DummyTableInheritanceRelated $parent): self
     {
         $this->parent = $parent;
 
diff --git a/tests/Fixtures/TestBundle/Entity/DummyTableInheritanceRelated.php b/tests/Fixtures/TestBundle/Entity/DummyTableInheritanceRelated.php
index 4e6e90022ec..89db172c75a 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyTableInheritanceRelated.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyTableInheritanceRelated.php
@@ -15,6 +15,7 @@
 
 use ApiPlatform\Core\Annotation\ApiResource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 
@@ -41,7 +42,7 @@ class DummyTableInheritanceRelated
     private $id;
 
     /**
-     * @var ArrayCollection Related children
+     * @var Collection Related children
      *
      * @ORM\OneToMany(targetEntity="DummyTableInheritance", mappedBy="parent")
      * @ORM\OrderBy({"id"="ASC"})
@@ -60,10 +61,7 @@ public function getId()
         return $this->id;
     }
 
-    /**
-     * @return ArrayCollection
-     */
-    public function getChildren()
+    public function getChildren(): Collection
     {
         return $this->children;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/DummyValidation.php b/tests/Fixtures/TestBundle/Entity/DummyValidation.php
index 214ae7e83df..248770d78b8 100644
--- a/tests/Fixtures/TestBundle/Entity/DummyValidation.php
+++ b/tests/Fixtures/TestBundle/Entity/DummyValidation.php
@@ -31,7 +31,7 @@
 class DummyValidation
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -56,83 +56,53 @@ class DummyValidation
     private $title;
 
     /**
-     * @var string The dummy code
+     * @var string|null The dummy code
      * @ORM\Column
      */
     private $code;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return DummyValidation
-     */
-    public function setId(int $id)
+    public function setId(int $id): self
     {
         $this->id = $id;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    /**
-     * @param string|null $name
-     *
-     * @return DummyValidation
-     */
-    public function setName($name)
+    public function setName(?string $name): self
     {
         $this->name = $name;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getTitle()
+    public function getTitle(): ?string
     {
         return $this->title;
     }
 
-    /**
-     * @param string|null $title
-     *
-     * @return DummyValidation
-     */
-    public function setTitle($title)
+    public function setTitle(?string $title): self
     {
         $this->title = $title;
 
         return $this;
     }
 
-    /**
-     * @return string
-     */
-    public function getCode()
+    public function getCode(): ?string
     {
         return $this->code;
     }
 
-    /**
-     * @param string $code
-     *
-     * @return DummyValidation
-     */
-    public function setCode($code)
+    public function setCode(string $code): self
     {
         $this->code = $code;
 
diff --git a/tests/Fixtures/TestBundle/Entity/EmbeddableDummy.php b/tests/Fixtures/TestBundle/Entity/EmbeddableDummy.php
index 7ba0fe6a559..514dbd5b83d 100644
--- a/tests/Fixtures/TestBundle/Entity/EmbeddableDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/EmbeddableDummy.php
@@ -35,14 +35,14 @@ class EmbeddableDummy
     private $dummyName;
 
     /**
-     * @var bool A dummy boolean
+     * @var bool|null A dummy boolean
      *
      * @ORM\Column(type="boolean", nullable=true)
      */
     public $dummyBoolean;
 
     /**
-     * @var \DateTime A dummy date
+     * @var \DateTime|null A dummy date
      *
      * @ORM\Column(type="datetime", nullable=true)
      * @Assert\DateTime
@@ -50,14 +50,14 @@ class EmbeddableDummy
     public $dummyDate;
 
     /**
-     * @var string A dummy float
+     * @var float|null A dummy float
      *
      * @ORM\Column(type="float", nullable=true)
      */
     public $dummyFloat;
 
     /**
-     * @var string A dummy price
+     * @var string|null A dummy price
      *
      * @ORM\Column(type="decimal", precision=10, scale=2, nullable=true)
      */
@@ -77,10 +77,7 @@ public function __construct()
     {
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyName()
+    public function getDummyName(): ?string
     {
         return $this->dummyName;
     }
@@ -90,10 +87,7 @@ public function setDummyName(string $dummyName)
         $this->dummyName = $dummyName;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
@@ -103,10 +97,7 @@ public function setDummyBoolean(bool $dummyBoolean)
         $this->dummyBoolean = $dummyBoolean;
     }
 
-    /**
-     * @return \DateTime
-     */
-    public function getDummyDate()
+    public function getDummyDate(): ?\DateTime
     {
         return $this->dummyDate;
     }
@@ -116,23 +107,17 @@ public function setDummyDate(\DateTime $dummyDate)
         $this->dummyDate = $dummyDate;
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyFloat()
+    public function getDummyFloat(): ?float
     {
         return $this->dummyFloat;
     }
 
-    public function setDummyFloat(string $dummyFloat)
+    public function setDummyFloat(float $dummyFloat)
     {
         $this->dummyFloat = $dummyFloat;
     }
 
-    /**
-     * @return string
-     */
-    public function getDummyPrice()
+    public function getDummyPrice(): ?string
     {
         return $this->dummyPrice;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/EmbeddedDummy.php b/tests/Fixtures/TestBundle/Entity/EmbeddedDummy.php
index aba68494c95..d96dcf57e6f 100644
--- a/tests/Fixtures/TestBundle/Entity/EmbeddedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/EmbeddedDummy.php
@@ -105,10 +105,7 @@ public function setEmbeddedDummy(EmbeddableDummy $embeddedDummy)
         $this->embeddedDummy = $embeddedDummy;
     }
 
-    /**
-     * @return \DateTime
-     */
-    public function getDummyDate()
+    public function getDummyDate(): ?\DateTime
     {
         return $this->dummyDate;
     }
@@ -118,10 +115,7 @@ public function setDummyDate(\DateTime $dummyDate)
         $this->dummyDate = $dummyDate;
     }
 
-    /**
-     * @return RelatedDummy
-     */
-    public function getRelatedDummy()
+    public function getRelatedDummy(): ?RelatedDummy
     {
         return $this->relatedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Field.php b/tests/Fixtures/TestBundle/Entity/Field.php
index 6a39202bb85..92edfbed1fc 100644
--- a/tests/Fixtures/TestBundle/Entity/Field.php
+++ b/tests/Fixtures/TestBundle/Entity/Field.php
@@ -88,7 +88,10 @@ public function setValue(string $value): void
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return [
diff --git a/tests/Fixtures/TestBundle/Entity/FourthLevel.php b/tests/Fixtures/TestBundle/Entity/FourthLevel.php
index cf15505f07a..fd1b9064f4b 100644
--- a/tests/Fixtures/TestBundle/Entity/FourthLevel.php
+++ b/tests/Fixtures/TestBundle/Entity/FourthLevel.php
@@ -28,7 +28,7 @@
 class FourthLevel
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -37,7 +37,7 @@ class FourthLevel
     private $id;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @Groups({"barcelona", "chicago"})
@@ -49,26 +49,17 @@ class FourthLevel
      */
     public $badThirdLevel;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return int
-     */
-    public function getLevel()
+    public function getLevel(): ?int
     {
         return $this->level;
     }
 
-    /**
-     * @param int $level
-     */
-    public function setLevel($level)
+    public function setLevel(int $level)
     {
         $this->level = $level;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Greeting.php b/tests/Fixtures/TestBundle/Entity/Greeting.php
index 8faca4b3441..9b42ac8fada 100644
--- a/tests/Fixtures/TestBundle/Entity/Greeting.php
+++ b/tests/Fixtures/TestBundle/Entity/Greeting.php
@@ -46,7 +46,7 @@ class Greeting
      */
     public $recipient;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/IriOnlyDummy.php b/tests/Fixtures/TestBundle/Entity/IriOnlyDummy.php
index ffb6cbd8d6b..1252fc62303 100644
--- a/tests/Fixtures/TestBundle/Entity/IriOnlyDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/IriOnlyDummy.php
@@ -32,7 +32,7 @@
 class IriOnlyDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -41,18 +41,18 @@ class IriOnlyDummy
     private $id;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @ORM\Column(type="string")
      */
     private $foo;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getFoo(): string
+    public function getFoo(): ?string
     {
         return $this->foo;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/LegacySecuredDummy.php b/tests/Fixtures/TestBundle/Entity/LegacySecuredDummy.php
index 65bebaf2f9c..f3c50f07a25 100644
--- a/tests/Fixtures/TestBundle/Entity/LegacySecuredDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/LegacySecuredDummy.php
@@ -44,7 +44,7 @@
 class LegacySecuredDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -53,7 +53,7 @@ class LegacySecuredDummy
     private $id;
 
     /**
-     * @var string The title
+     * @var string|null The title
      *
      * @ORM\Column
      * @Assert\NotBlank
@@ -68,44 +68,44 @@ class LegacySecuredDummy
     private $description = '';
 
     /**
-     * @var string The owner
+     * @var string|null The owner
      *
      * @ORM\Column
      * @Assert\NotBlank
      */
     private $owner;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
 
-    public function setTitle(string $title)
+    public function setTitle(string $title): void
     {
         $this->title = $title;
     }
 
-    public function getDescription()
+    public function getDescription(): string
     {
         return $this->description;
     }
 
-    public function setDescription(string $description)
+    public function setDescription(string $description): void
     {
         $this->description = $description;
     }
 
-    public function getOwner(): string
+    public function getOwner(): ?string
     {
         return $this->owner;
     }
 
-    public function setOwner(string $owner)
+    public function setOwner(string $owner): void
     {
         $this->owner = $owner;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/Question.php b/tests/Fixtures/TestBundle/Entity/Question.php
index 64385800378..673eadbd125 100644
--- a/tests/Fixtures/TestBundle/Entity/Question.php
+++ b/tests/Fixtures/TestBundle/Entity/Question.php
@@ -46,10 +46,8 @@ class Question
      * Set content.
      *
      * @param string $content
-     *
-     * @return Question
      */
-    public function setContent($content)
+    public function setContent($content): self
     {
         $this->content = $content;
 
@@ -58,20 +56,16 @@ public function setContent($content)
 
     /**
      * Get content.
-     *
-     * @return string
      */
-    public function getContent()
+    public function getContent(): ?string
     {
         return $this->content;
     }
 
     /**
      * Get id.
-     *
-     * @return string
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
@@ -80,10 +74,8 @@ public function getId()
      * Set answer.
      *
      * @param Answer $answer
-     *
-     * @return Question
      */
-    public function setAnswer(Answer $answer = null)
+    public function setAnswer(Answer $answer = null): self
     {
         $this->answer = $answer;
 
@@ -92,10 +84,8 @@ public function setAnswer(Answer $answer = null)
 
     /**
      * Get answer.
-     *
-     * @return Answer
      */
-    public function getAnswer()
+    public function getAnswer(): ?Answer
     {
         return $this->answer;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RamseyUuidDummy.php b/tests/Fixtures/TestBundle/Entity/RamseyUuidDummy.php
index 15b72be3242..5e04ad43a24 100644
--- a/tests/Fixtures/TestBundle/Entity/RamseyUuidDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RamseyUuidDummy.php
@@ -54,7 +54,7 @@ public function getOther(): ?UuidInterface
         return $this->other;
     }
 
-    public function setOther(UuidInterface $other)
+    public function setOther(UuidInterface $other): void
     {
         $this->other = $other;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedDummy.php b/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
index ec4eacf89d7..9ee9e00c812 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
@@ -17,6 +17,7 @@
 use ApiPlatform\Core\Annotation\ApiResource;
 use ApiPlatform\Core\Annotation\ApiSubresource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -42,7 +43,7 @@ class RelatedDummy extends ParentDummy
     private $id;
 
     /**
-     * @var string A name
+     * @var string|null A name
      *
      * @ORM\Column(nullable=true)
      * @Groups({"friends"})
@@ -56,7 +57,7 @@ class RelatedDummy extends ParentDummy
     protected $symfony = 'symfony';
 
     /**
-     * @var \DateTime A dummy date
+     * @var \DateTime|null A dummy date
      *
      * @ORM\Column(type="datetime", nullable=true)
      * @Assert\DateTime
@@ -79,7 +80,7 @@ class RelatedDummy extends ParentDummy
     public $relatedToDummyFriend;
 
     /**
-     * @var bool A dummy bool
+     * @var bool|null A dummy bool
      *
      * @ORM\Column(type="boolean", nullable=true)
      * @Groups({"friends"})
@@ -140,10 +141,7 @@ public function getDummyDate()
         return $this->dummyDate;
     }
 
-    /**
-     * @return bool
-     */
-    public function isDummyBoolean()
+    public function isDummyBoolean(): ?bool
     {
         return $this->dummyBoolean;
     }
@@ -156,10 +154,7 @@ public function setDummyBoolean($dummyBoolean)
         $this->dummyBoolean = $dummyBoolean;
     }
 
-    /**
-     * @return ThirdLevel|null
-     */
-    public function getThirdLevel()
+    public function getThirdLevel(): ?ThirdLevel
     {
         return $this->thirdLevel;
     }
@@ -172,9 +167,9 @@ public function setThirdLevel(ThirdLevel $thirdLevel = null)
     /**
      * Get relatedToDummyFriend.
      *
-     * @return RelatedToDummyFriend[]
+     * @return Collection<RelatedToDummyFriend>
      */
-    public function getRelatedToDummyFriend()
+    public function getRelatedToDummyFriend(): Collection
     {
         return $this->relatedToDummyFriend;
     }
@@ -189,10 +184,7 @@ public function addRelatedToDummyFriend(RelatedToDummyFriend $relatedToDummyFrie
         $this->relatedToDummyFriend->add($relatedToDummyFriend);
     }
 
-    /**
-     * @return EmbeddableDummy
-     */
-    public function getEmbeddedDummy()
+    public function getEmbeddedDummy(): EmbeddableDummy
     {
         return $this->embeddedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedNormalizedDummy.php b/tests/Fixtures/TestBundle/Entity/RelatedNormalizedDummy.php
index d213bff107c..27ec42f29b3 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedNormalizedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedNormalizedDummy.php
@@ -16,6 +16,7 @@
 use ApiPlatform\Core\Annotation\ApiProperty;
 use ApiPlatform\Core\Annotation\ApiResource;
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -34,7 +35,7 @@
 class RelatedNormalizedDummy
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -44,7 +45,7 @@ class RelatedNormalizedDummy
     private $id;
 
     /**
-     * @var string The dummy name
+     * @var string|null The dummy name
      *
      * @ORM\Column
      * @Assert\NotBlank
@@ -54,7 +55,7 @@ class RelatedNormalizedDummy
     private $name;
 
     /**
-     * @var ArrayCollection Several Normalized dummies
+     * @var Collection Several Normalized dummies
      *
      * @ORM\ManyToMany(targetEntity="CustomNormalizedDummy")
      * @Groups({"related_output", "related_input"})
@@ -66,36 +67,30 @@ public function __construct()
         $this->customNormalizedDummy = new ArrayCollection();
     }
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @param string $name
-     */
-    public function setName($name)
+    public function setName(string $name): void
     {
         $this->name = $name;
     }
 
-    public function getName(): string
+    public function getName(): ?string
     {
         return $this->name;
     }
 
-    /**
-     * @return ArrayCollection
-     */
-    public function getCustomNormalizedDummy()
+    public function getCustomNormalizedDummy(): Collection
     {
         return $this->customNormalizedDummy;
     }
 
     /**
-     * @param ArrayCollection $customNormalizedDummy
+     * @param Collection|array $customNormalizedDummy
      */
-    public function setCustomNormalizedDummy($customNormalizedDummy)
+    public function setCustomNormalizedDummy($customNormalizedDummy): void
     {
         $this->customNormalizedDummy = $customNormalizedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedOwnedDummy.php b/tests/Fixtures/TestBundle/Entity/RelatedOwnedDummy.php
index abb771e4046..e0aaf20e905 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedOwnedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedOwnedDummy.php
@@ -35,14 +35,14 @@ class RelatedOwnedDummy
     private $id;
 
     /**
-     * @var string A name
+     * @var string|null A name
      *
      * @ORM\Column(nullable=true)
      */
     public $name;
 
     /**
-     * @var Dummy
+     * @var Dummy|null
      *
      * @ORM\OneToOne(targetEntity="Dummy", cascade={"persist"}, inversedBy="relatedOwnedDummy")
      * @ORM\JoinColumn(nullable=false)
@@ -50,32 +50,30 @@ class RelatedOwnedDummy
      */
     public $owningDummy;
 
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function setId($id)
+    public function setId(int $id): void
     {
         $this->id = $id;
     }
 
-    public function setName($name)
+    public function setName(?string $name): void
     {
         $this->name = $name;
     }
 
-    public function getName()
+    public function getName(): ?string
     {
         return $this->name;
     }
 
     /**
      * Get owning dummy.
-     *
-     * @return Dummy
      */
-    public function getOwningDummy()
+    public function getOwningDummy(): ?Dummy
     {
         return $this->owningDummy;
     }
@@ -85,7 +83,7 @@ public function getOwningDummy()
      *
      * @param Dummy $owningDummy the value to set
      */
-    public function setOwningDummy(Dummy $owningDummy)
+    public function setOwningDummy(Dummy $owningDummy): void
     {
         $this->owningDummy = $owningDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedOwningDummy.php b/tests/Fixtures/TestBundle/Entity/RelatedOwningDummy.php
index 53d32372233..bd20339581e 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedOwningDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedOwningDummy.php
@@ -71,10 +71,8 @@ public function getName()
 
     /**
      * Get owned dummy.
-     *
-     * @return Dummy
      */
-    public function getOwnedDummy()
+    public function getOwnedDummy(): Dummy
     {
         return $this->ownedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedToDummyFriend.php b/tests/Fixtures/TestBundle/Entity/RelatedToDummyFriend.php
index 8fd241dd773..01e437dcbfd 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedToDummyFriend.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedToDummyFriend.php
@@ -72,10 +72,7 @@ public function getName()
         return $this->name;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getDescription()
+    public function getDescription(): ?string
     {
         return $this->description;
     }
@@ -90,10 +87,8 @@ public function setDescription($description)
 
     /**
      * Gets dummyFriend.
-     *
-     * @return DummyFriend
      */
-    public function getDummyFriend()
+    public function getDummyFriend(): DummyFriend
     {
         return $this->dummyFriend;
     }
@@ -110,10 +105,8 @@ public function setDummyFriend(DummyFriend $dummyFriend)
 
     /**
      * Gets relatedDummy.
-     *
-     * @return RelatedDummy
      */
-    public function getRelatedDummy()
+    public function getRelatedDummy(): RelatedDummy
     {
         return $this->relatedDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/SecuredDummy.php b/tests/Fixtures/TestBundle/Entity/SecuredDummy.php
index 19ffc2cc816..d3b21bd055a 100644
--- a/tests/Fixtures/TestBundle/Entity/SecuredDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/SecuredDummy.php
@@ -51,7 +51,7 @@
 class SecuredDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -60,7 +60,7 @@ class SecuredDummy
     private $id;
 
     /**
-     * @var string The title
+     * @var string|null The title
      *
      * @ORM\Column
      * @Assert\NotBlank
@@ -83,34 +83,34 @@ class SecuredDummy
     private $adminOnlyProperty = '';
 
     /**
-     * @var string The owner
+     * @var string|null The owner
      *
      * @ORM\Column
      * @Assert\NotBlank
      */
     private $owner;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getTitle(): string
+    public function getTitle(): ?string
     {
         return $this->title;
     }
 
-    public function setTitle(string $title)
+    public function setTitle(string $title): void
     {
         $this->title = $title;
     }
 
-    public function getDescription()
+    public function getDescription(): string
     {
         return $this->description;
     }
 
-    public function setDescription(string $description)
+    public function setDescription(string $description): void
     {
         $this->description = $description;
     }
@@ -120,17 +120,17 @@ public function getAdminOnlyProperty(): ?string
         return $this->adminOnlyProperty;
     }
 
-    public function setAdminOnlyProperty(?string $adminOnlyProperty)
+    public function setAdminOnlyProperty(?string $adminOnlyProperty): void
     {
         $this->adminOnlyProperty = $adminOnlyProperty;
     }
 
-    public function getOwner(): string
+    public function getOwner(): ?string
     {
         return $this->owner;
     }
 
-    public function setOwner(string $owner)
+    public function setOwner(string $owner): void
     {
         $this->owner = $owner;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/SlugChildDummy.php b/tests/Fixtures/TestBundle/Entity/SlugChildDummy.php
index 5c89cacaad3..7e2428676ec 100644
--- a/tests/Fixtures/TestBundle/Entity/SlugChildDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/SlugChildDummy.php
@@ -25,7 +25,7 @@
 class SlugChildDummy
 {
     /**
-     * @var int The identifier
+     * @var int|null The identifier
      *
      * @ApiProperty(identifier=false)
      *
@@ -36,7 +36,7 @@ class SlugChildDummy
     private $id;
 
     /**
-     * @var string The slug used as API identifier
+     * @var string|null The slug used as API identifier
      *
      * @ApiProperty(identifier=true)
      *
@@ -52,31 +52,22 @@ class SlugChildDummy
      */
     private $parentDummy;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): ?string
     {
         return $this->slug;
     }
 
-    public function setSlug(string $slug)
+    public function setSlug(string $slug): void
     {
         $this->slug = $slug;
     }
 
-    /**
-     * @return SlugParentDummy
-     */
-    public function getParentDummy()
+    public function getParentDummy(): ?SlugParentDummy
     {
         return $this->parentDummy;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/SlugParentDummy.php b/tests/Fixtures/TestBundle/Entity/SlugParentDummy.php
index c24e784cc91..1876543d7a2 100644
--- a/tests/Fixtures/TestBundle/Entity/SlugParentDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/SlugParentDummy.php
@@ -29,7 +29,7 @@
 class SlugParentDummy
 {
     /**
-     * @var int The database identifier
+     * @var int|null The database identifier
      *
      * @ApiProperty(identifier=false)
      *
@@ -40,7 +40,7 @@ class SlugParentDummy
     private $id;
 
     /**
-     * @var string The slug used a API identifier
+     * @var string|null The slug used a API identifier
      *
      * @ApiProperty(identifier=true)
      *
@@ -60,26 +60,17 @@ public function __construct()
         $this->childDummies = new ArrayCollection();
     }
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return string
-     */
-    public function getSlug()
+    public function getSlug(): ?string
     {
         return $this->slug;
     }
 
-    /**
-     * @param string $slug
-     */
-    public function setSlug($slug)
+    public function setSlug(string $slug): void
     {
         $this->slug = $slug;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/SymfonyUuidDummy.php b/tests/Fixtures/TestBundle/Entity/SymfonyUuidDummy.php
index 98b5f0da7dd..5b07148082c 100644
--- a/tests/Fixtures/TestBundle/Entity/SymfonyUuidDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/SymfonyUuidDummy.php
@@ -40,7 +40,7 @@ class SymfonyUuidDummy
          */
         private $number;
 
-        public function __construct($id = null)
+        public function __construct(?Uuid $id = null)
         {
             $this->id = $id ?? Uuid::v4();
         }
diff --git a/tests/Fixtures/TestBundle/Entity/ThirdLevel.php b/tests/Fixtures/TestBundle/Entity/ThirdLevel.php
index 54996296200..f78570ff64b 100644
--- a/tests/Fixtures/TestBundle/Entity/ThirdLevel.php
+++ b/tests/Fixtures/TestBundle/Entity/ThirdLevel.php
@@ -29,7 +29,7 @@
 class ThirdLevel
 {
     /**
-     * @var int The id
+     * @var int|null The id
      *
      * @ORM\Column(type="integer")
      * @ORM\Id
@@ -38,7 +38,7 @@ class ThirdLevel
     private $id;
 
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer")
      * @Groups({"barcelona", "chicago"})
@@ -64,18 +64,12 @@ class ThirdLevel
      */
     public $badFourthLevel;
 
-    /**
-     * @return int
-     */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    /**
-     * @return int
-     */
-    public function getLevel()
+    public function getLevel(): ?int
     {
         return $this->level;
     }
@@ -88,10 +82,7 @@ public function setLevel($level)
         $this->level = $level;
     }
 
-    /**
-     * @return bool
-     */
-    public function isTest()
+    public function isTest(): bool
     {
         return $this->test;
     }
@@ -104,10 +95,7 @@ public function setTest($test)
         $this->test = $test;
     }
 
-    /**
-     * @return FourthLevel|null
-     */
-    public function getFourthLevel()
+    public function getFourthLevel(): ?FourthLevel
     {
         return $this->fourthLevel;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/TruncatedDummy.php b/tests/Fixtures/TestBundle/Entity/TruncatedDummy.php
index 8961bc251d1..002828e10d4 100644
--- a/tests/Fixtures/TestBundle/Entity/TruncatedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/TruncatedDummy.php
@@ -36,10 +36,8 @@ class TruncatedDummy
 
     /**
      * Get id.
-     *
-     * @return string
      */
-    public function getId()
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Entity/User.php b/tests/Fixtures/TestBundle/Entity/User.php
index 616b9d4a8d0..464ca12d6ed 100644
--- a/tests/Fixtures/TestBundle/Entity/User.php
+++ b/tests/Fixtures/TestBundle/Entity/User.php
@@ -62,7 +62,7 @@
 class User extends AbstractSecurityUser
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Id
      * @ORM\Column(type="integer")
@@ -93,18 +93,18 @@ class User extends AbstractSecurityUser
     private $plainPassword;
 
     /**
-     * @var string
+     * @var string|null
      *
      * @Groups({"user"})
      */
     private $username;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
 
-    public function getEmail(): string
+    public function getEmail(): ?string
     {
         return $this->email;
     }
@@ -124,22 +124,14 @@ public function setPlainPassword(string $plainPassword): void
         $this->plainPassword = $plainPassword;
     }
 
-    /**
-     * @param string|null $fullname
-     *
-     * @return $this
-     */
-    public function setFullname($fullname)
+    public function setFullname(?string $fullname): self
     {
         $this->fullname = $fullname;
 
         return $this;
     }
 
-    /**
-     * @return string|null
-     */
-    public function getFullname()
+    public function getFullname(): ?string
     {
         return $this->fullname;
     }
@@ -164,12 +156,12 @@ public function getPassword(): ?string
         return null;
     }
 
-    public function getSalt()
+    public function getSalt(): ?string
     {
         return null;
     }
 
-    public function eraseCredentials()
+    public function eraseCredentials(): void
     {
     }
 }
diff --git a/tests/Fixtures/TestBundle/Entity/WithJsonDummy.php b/tests/Fixtures/TestBundle/Entity/WithJsonDummy.php
index a2769c87c1f..30110fe10dd 100644
--- a/tests/Fixtures/TestBundle/Entity/WithJsonDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/WithJsonDummy.php
@@ -23,7 +23,7 @@
 class WithJsonDummy
 {
     /**
-     * @var int
+     * @var int|null
      *
      * @ORM\Column(type="integer", nullable=true)
      * @ORM\Id
@@ -38,7 +38,7 @@ class WithJsonDummy
      */
     public $json;
 
-    public function getId(): int
+    public function getId(): ?int
     {
         return $this->id;
     }
diff --git a/tests/Fixtures/TestBundle/Enum/ContentStatus.php b/tests/Fixtures/TestBundle/Enum/ContentStatus.php
index d64310f443b..e1e212265cd 100644
--- a/tests/Fixtures/TestBundle/Enum/ContentStatus.php
+++ b/tests/Fixtures/TestBundle/Enum/ContentStatus.php
@@ -68,7 +68,10 @@ public static function search(string $value)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return [
diff --git a/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemDocumentResolver.php b/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemDocumentResolver.php
index a4acf694b91..3bfa5c69d98 100644
--- a/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemDocumentResolver.php
+++ b/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemDocumentResolver.php
@@ -26,10 +26,8 @@ class DummyCustomQueryNoReadAndSerializeItemDocumentResolver implements QueryIte
 {
     /**
      * @param DummyCustomQueryDocument|null $item
-     *
-     * @return DummyCustomQueryDocument
      */
-    public function __invoke($item, array $context)
+    public function __invoke($item, array $context): DummyCustomQueryDocument
     {
         if (null !== $item) {
             throw new RuntimeException('Item should be null');
diff --git a/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemResolver.php b/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemResolver.php
index 8b55554f012..ecb7d9a33cb 100644
--- a/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemResolver.php
+++ b/tests/Fixtures/TestBundle/GraphQl/Resolver/DummyCustomQueryNoReadAndSerializeItemResolver.php
@@ -26,10 +26,8 @@ class DummyCustomQueryNoReadAndSerializeItemResolver implements QueryItemResolve
 {
     /**
      * @param DummyCustomQuery|null $item
-     *
-     * @return DummyCustomQuery
      */
-    public function __invoke($item, array $context)
+    public function __invoke($item, array $context): DummyCustomQuery
     {
         if (null !== $item) {
             throw new RuntimeException('Item should be null');
diff --git a/tests/Fixtures/TestBundle/GraphQl/Type/Definition/DateTimeType.php b/tests/Fixtures/TestBundle/GraphQl/Type/Definition/DateTimeType.php
index d6b64b656c8..fb136c1ede5 100644
--- a/tests/Fixtures/TestBundle/GraphQl/Type/Definition/DateTimeType.php
+++ b/tests/Fixtures/TestBundle/GraphQl/Type/Definition/DateTimeType.php
@@ -42,6 +42,8 @@ public function getName(): string
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function serialize($value)
     {
@@ -60,6 +62,8 @@ public function serialize($value)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function parseValue($value)
     {
@@ -77,6 +81,8 @@ public function parseValue($value)
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function parseLiteral(Node $valueNode, ?array $variables = null)
     {
diff --git a/tests/Fixtures/TestBundle/Serializer/Denormalizer/SerializableResourceDenormalizer.php b/tests/Fixtures/TestBundle/Serializer/Denormalizer/SerializableResourceDenormalizer.php
index 9d2e8f52df1..a997ede8589 100644
--- a/tests/Fixtures/TestBundle/Serializer/Denormalizer/SerializableResourceDenormalizer.php
+++ b/tests/Fixtures/TestBundle/Serializer/Denormalizer/SerializableResourceDenormalizer.php
@@ -23,6 +23,8 @@ class SerializableResourceDenormalizer implements DenormalizerInterface
 {
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     public function denormalize($data, $class, $format = null, array $context = [])
     {
@@ -37,7 +39,7 @@ public function denormalize($data, $class, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsDenormalization($data, $type, $format = null)
+    public function supportsDenormalization($data, $type, $format = null): bool
     {
         return 'json' === $format && SerializableResource::class === $type && \is_array($data);
     }
diff --git a/tests/Fixtures/TestBundle/Serializer/NameConverter/CustomConverter.php b/tests/Fixtures/TestBundle/Serializer/NameConverter/CustomConverter.php
index 11d8be1806e..74489a5cf9f 100644
--- a/tests/Fixtures/TestBundle/Serializer/NameConverter/CustomConverter.php
+++ b/tests/Fixtures/TestBundle/Serializer/NameConverter/CustomConverter.php
@@ -21,12 +21,12 @@
  */
 class CustomConverter extends CamelCaseToSnakeCaseNameConverter
 {
-    public function normalize($propertyName)
+    public function normalize($propertyName): string
     {
         return 'nameConverted' === $propertyName ? parent::normalize($propertyName) : $propertyName;
     }
 
-    public function denormalize($propertyName)
+    public function denormalize($propertyName): string
     {
         return 'name_converted' === $propertyName ? parent::denormalize($propertyName) : $propertyName;
     }
diff --git a/tests/Fixtures/TestBundle/Serializer/Normalizer/OverrideDocumentationNormalizer.php b/tests/Fixtures/TestBundle/Serializer/Normalizer/OverrideDocumentationNormalizer.php
index 69da8eb7281..cdc614fe52e 100644
--- a/tests/Fixtures/TestBundle/Serializer/Normalizer/OverrideDocumentationNormalizer.php
+++ b/tests/Fixtures/TestBundle/Serializer/Normalizer/OverrideDocumentationNormalizer.php
@@ -44,7 +44,11 @@ public function normalize($object, $format = null, array $context = [])
         return $data;
     }
 
-    public function supportsNormalization($data, $format = null)
+    /**
+     * @param mixed|null $format
+     * @param mixed      $data
+     */
+    public function supportsNormalization($data, $format = null): bool
     {
         return $this->documentationNormalizer->supportsNormalization($data, $format);
     }
diff --git a/tests/Metadata/Property/Factory/AnnotationPropertyMetadataFactoryTest.php b/tests/Metadata/Property/Factory/AnnotationPropertyMetadataFactoryTest.php
index aa906801559..2773a975cf0 100644
--- a/tests/Metadata/Property/Factory/AnnotationPropertyMetadataFactoryTest.php
+++ b/tests/Metadata/Property/Factory/AnnotationPropertyMetadataFactoryTest.php
@@ -34,6 +34,9 @@ class AnnotationPropertyMetadataFactoryTest extends TestCase
 
     /**
      * @dataProvider dependenciesProvider
+     *
+     * @param mixed $reader
+     * @param mixed $decorated
      */
     public function testCreateProperty($reader, $decorated, string $description)
     {
diff --git a/tests/Metadata/Property/Factory/AnnotationPropertyNameCollectionFactoryTest.php b/tests/Metadata/Property/Factory/AnnotationPropertyNameCollectionFactoryTest.php
index 3aeccc4c767..2987917c159 100644
--- a/tests/Metadata/Property/Factory/AnnotationPropertyNameCollectionFactoryTest.php
+++ b/tests/Metadata/Property/Factory/AnnotationPropertyNameCollectionFactoryTest.php
@@ -35,6 +35,8 @@ class AnnotationPropertyNameCollectionFactoryTest extends TestCase
 
     /**
      * @dataProvider dependenciesProvider
+     *
+     * @param mixed $decorated
      */
     public function testCreate($decorated, array $results)
     {
@@ -80,6 +82,8 @@ public function testCreateAttribute()
 
     /**
      * @dataProvider upperCaseDependenciesProvider
+     *
+     * @param mixed $decorated
      */
     public function testUpperCaseCreate($decorated, array $results)
     {
diff --git a/tests/Metadata/Property/Factory/AnnotationSubresourceMetadataFactoryTest.php b/tests/Metadata/Property/Factory/AnnotationSubresourceMetadataFactoryTest.php
index 89562cf825f..fb14f8bfbe0 100644
--- a/tests/Metadata/Property/Factory/AnnotationSubresourceMetadataFactoryTest.php
+++ b/tests/Metadata/Property/Factory/AnnotationSubresourceMetadataFactoryTest.php
@@ -34,6 +34,9 @@ class AnnotationSubresourceMetadataFactoryTest extends TestCase
 
     /**
      * @dataProvider dependenciesProvider
+     *
+     * @param mixed $reader
+     * @param mixed $decorated
      */
     public function testCreateProperty($reader, $decorated)
     {
diff --git a/tests/Metadata/Property/Factory/SerializerPropertyMetadataFactoryTest.php b/tests/Metadata/Property/Factory/SerializerPropertyMetadataFactoryTest.php
index 5ed15722d24..dea35c20d71 100644
--- a/tests/Metadata/Property/Factory/SerializerPropertyMetadataFactoryTest.php
+++ b/tests/Metadata/Property/Factory/SerializerPropertyMetadataFactoryTest.php
@@ -56,6 +56,9 @@ public function testConstruct()
 
     /**
      * @dataProvider groupsProvider
+     *
+     * @param mixed $readGroups
+     * @param mixed $writeGroups
      */
     public function testCreate($readGroups, $writeGroups, ?string $relatedOutputClass = null)
     {
diff --git a/tests/Metadata/Resource/Factory/AnnotationResourceMetadataFactoryTest.php b/tests/Metadata/Resource/Factory/AnnotationResourceMetadataFactoryTest.php
index c06f1e0c0a8..8d81915c359 100644
--- a/tests/Metadata/Resource/Factory/AnnotationResourceMetadataFactoryTest.php
+++ b/tests/Metadata/Resource/Factory/AnnotationResourceMetadataFactoryTest.php
@@ -34,6 +34,9 @@ class AnnotationResourceMetadataFactoryTest extends TestCase
 
     /**
      * @dataProvider getCreateDependencies
+     *
+     * @param mixed $reader
+     * @param mixed $decorated
      */
     public function testCreate($reader, $decorated, string $expectedShortName, ?string $expectedDescription)
     {
diff --git a/tests/Metadata/Resource/Factory/ExtractorResourceMetadataFactoryTest.php b/tests/Metadata/Resource/Factory/ExtractorResourceMetadataFactoryTest.php
index 07f700a8d68..39062ea34b6 100644
--- a/tests/Metadata/Resource/Factory/ExtractorResourceMetadataFactoryTest.php
+++ b/tests/Metadata/Resource/Factory/ExtractorResourceMetadataFactoryTest.php
@@ -39,6 +39,8 @@ class ExtractorResourceMetadataFactoryTest extends FileConfigurationMetadataFact
 
     /**
      * @dataProvider resourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testXmlCreateResourceMetadata($expectedResourceMetadata)
     {
@@ -66,6 +68,8 @@ public function testXmlDoesNotExistMetadataFactory()
 
     /**
      * @dataProvider optionalResourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testXmlOptionalResourceMetadata($expectedResourceMetadata)
     {
@@ -81,6 +85,8 @@ public function testXmlOptionalResourceMetadata($expectedResourceMetadata)
      * @expectedDeprecation Configuring "%s" tags without using a parent "%ss" tag is deprecated since API Platform 2.1 and will not be possible anymore in API Platform 3
      * @group legacy
      * @dataProvider legacyOperationsResourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testLegacyOperationsResourceMetadata($expectedResourceMetadata)
     {
@@ -94,6 +100,8 @@ public function testLegacyOperationsResourceMetadata($expectedResourceMetadata)
 
     /**
      * @dataProvider noCollectionOperationsResourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testXmlNoCollectionOperationsResourceMetadata($expectedResourceMetadata)
     {
@@ -107,6 +115,8 @@ public function testXmlNoCollectionOperationsResourceMetadata($expectedResourceM
 
     /**
      * @dataProvider noItemOperationsResourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testXmlNoItemOperationsResourceMetadata($expectedResourceMetadata)
     {
@@ -192,6 +202,8 @@ public function testYamlDoesNotExistMetadataFactory()
 
     /**
      * @dataProvider optionalResourceMetadataProvider
+     *
+     * @param mixed $expectedResourceMetadata
      */
     public function testYamlOptionalResourceMetadata($expectedResourceMetadata)
     {
diff --git a/tests/Metadata/Resource/Factory/InputOutputResourceMetadataFactoryTest.php b/tests/Metadata/Resource/Factory/InputOutputResourceMetadataFactoryTest.php
index a3381deab22..9796872e3d0 100644
--- a/tests/Metadata/Resource/Factory/InputOutputResourceMetadataFactoryTest.php
+++ b/tests/Metadata/Resource/Factory/InputOutputResourceMetadataFactoryTest.php
@@ -26,6 +26,9 @@ class InputOutputResourceMetadataFactoryTest extends TestCase
 
     /**
      * @dataProvider getAttributes
+     *
+     * @param mixed $attributes
+     * @param mixed $expected
      */
     public function testInputOutputMetadata($attributes, $expected)
     {
@@ -40,6 +43,9 @@ public function testInputOutputMetadata($attributes, $expected)
 
     /**
      * @dataProvider getAttributes
+     *
+     * @param mixed $attributes
+     * @param mixed $expected
      */
     public function testInputOutputViaGraphQlMetadata($attributes, $expected)
     {
diff --git a/tests/Metadata/Resource/ResourceMetadataTest.php b/tests/Metadata/Resource/ResourceMetadataTest.php
index 33f9cd12b45..863f5a447f4 100644
--- a/tests/Metadata/Resource/ResourceMetadataTest.php
+++ b/tests/Metadata/Resource/ResourceMetadataTest.php
@@ -73,6 +73,8 @@ public function testValueObject()
 
     /**
      * @dataProvider getWithMethods
+     *
+     * @param mixed $value
      */
     public function testWithMethods(string $name, $value)
     {
diff --git a/tests/Swagger/Serializer/DocumentationNormalizerV2Test.php b/tests/Swagger/Serializer/DocumentationNormalizerV2Test.php
index 318f10774a8..24c1539c570 100644
--- a/tests/Swagger/Serializer/DocumentationNormalizerV2Test.php
+++ b/tests/Swagger/Serializer/DocumentationNormalizerV2Test.php
@@ -3394,6 +3394,9 @@ private function doTestNormalizeWithInputAndOutputClass(): void
 
     /**
      * @dataProvider propertyWithDefaultProvider
+     *
+     * @param mixed $expectedDefault
+     * @param mixed $expectedExample
      */
     public function testNormalizeWithDefaultProperty($expectedDefault, $expectedExample, PropertyMetadata $propertyMetadata)
     {
diff --git a/tests/Util/RequestParserTest.php b/tests/Util/RequestParserTest.php
index 7433d2f2f9a..114e2241311 100644
--- a/tests/Util/RequestParserTest.php
+++ b/tests/Util/RequestParserTest.php
@@ -31,6 +31,9 @@ public function testParseAndDuplicateRequest()
 
     /**
      * @dataProvider parseRequestParamsProvider
+     *
+     * @param mixed $source
+     * @param mixed $expected
      */
     public function testParseRequestParams($source, $expected)
     {