Improve null checks in drivers with a delegate

src/Metadata/Driver/AbstractDoctrineTypeDriver.php

@@ -83,6 +83,11 @@ public function __construct(DriverInterface $delegate, ManagerRegistry $registry
     public function loadMetadataForClass(\ReflectionClass $class): ?BaseClassMetadata
     {
         $classMetadata = $this->delegate->loadMetadataForClass($class);
+
+        if (null === $classMetadata) {
+            return null;
+        }
+
         \assert($classMetadata instanceof ClassMetadata);
 
         // Abort if the given class is not a mapped entity

src/Metadata/Driver/DefaultValuePropertyDriver.php

@@ -30,12 +30,13 @@ public function __construct(DriverInterface $delegate)
     public function loadMetadataForClass(ReflectionClass $class): ?ClassMetadata
     {
         $classMetadata = $this->delegate->loadMetadataForClass($class);
-        \assert($classMetadata instanceof SerializerClassMetadata);
 
         if (null === $classMetadata) {
             return null;
         }
 
+        \assert($classMetadata instanceof SerializerClassMetadata);
+
         foreach ($classMetadata->propertyMetadata as $key => $propertyMetadata) {
             \assert($propertyMetadata instanceof PropertyMetadata);
             if (null !== $propertyMetadata->hasDefault) {

src/Metadata/Driver/DocBlockDriver.php

@@ -45,12 +45,13 @@ public function __construct(DriverInterface $delegate, ?ParserInterface $typePar
     public function loadMetadataForClass(ReflectionClass $class): ?ClassMetadata
     {
         $classMetadata = $this->delegate->loadMetadataForClass($class);
-        \assert($classMetadata instanceof SerializerClassMetadata);
 
         if (null === $classMetadata) {
             return null;
         }
 
+        \assert($classMetadata instanceof SerializerClassMetadata);
+
         // We base our scan on the internal driver's property list so that we
         // respect any internal allow/blocklist like in the AnnotationDriver
         foreach ($classMetadata->propertyMetadata as $key => $propertyMetadata) {

src/Metadata/Driver/EnumPropertiesDriver.php

@@ -30,12 +30,13 @@ public function __construct(DriverInterface $delegate)
     public function loadMetadataForClass(ReflectionClass $class): ?ClassMetadata
     {
         $classMetadata = $this->delegate->loadMetadataForClass($class);
-        \assert($classMetadata instanceof SerializerClassMetadata);
 
         if (null === $classMetadata) {
             return null;
         }
 
+        \assert($classMetadata instanceof SerializerClassMetadata);
+
         // We base our scan on the internal driver's property list so that we
         // respect any internal allow/blocklist like in the AnnotationDriver
         foreach ($classMetadata->propertyMetadata as $propertyMetadata) {

src/Metadata/Driver/TypedPropertiesDriver.php

@@ -67,6 +67,11 @@ private function getDefaultWhiteList(): array
     public function loadMetadataForClass(ReflectionClass $class): ?ClassMetadata
     {
         $classMetadata = $this->delegate->loadMetadataForClass($class);
+
+        if (null === $classMetadata) {
+            return null;
+        }
+
         \assert($classMetadata instanceof SerializerClassMetadata);
 
         if (PHP_VERSION_ID <= 70400) {