[Serializer] Add missing types to BackedEnumNormalizer

Author: nicolas-grekas

Normalizer/BackedEnumNormalizer.php

@@ -29,7 +29,7 @@ final class BackedEnumNormalizer implements NormalizerInterface, DenormalizerInt
      *
      * @return int|string
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, string $format = null, array $context = [])
     {
         if (!$object instanceof \BackedEnum) {
             throw new InvalidArgumentException('The data must belong to a backed enumeration.');
@@ -41,7 +41,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null): bool
+    public function supportsNormalization($data, string $format = null): bool
     {
         return $data instanceof \BackedEnum;
     }
@@ -51,7 +51,7 @@ public function supportsNormalization($data, $format = null): bool
      *
      * @throws NotNormalizableValueException
      */
-    public function denormalize($data, $type, $format = null, array $context = [])
+    public function denormalize($data, string $type, string $format = null, array $context = [])
     {
         if (!is_subclass_of($type, \BackedEnum::class)) {
             throw new InvalidArgumentException('The data must belong to a backed enumeration.');
@@ -71,7 +71,7 @@ public function denormalize($data, $type, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsDenormalization($data, $type, $format = null): bool
+    public function supportsDenormalization($data, string $type, string $format = null): bool
     {
         return is_subclass_of($type, \BackedEnum::class);
     }