fix(jsonapi): use parent-resolved class in denormalizeRelation

src/JsonApi/Serializer/ItemNormalizer.php

@@ -278,22 +278,9 @@ protected function denormalizeRelation(string $attributeName, ApiProperty $prope
                 return $this->iriConverter->getResourceFromIri($value['id'], $context);
             }
 
-            $targetClass = null;
-            $nativeType = $propertyMetadata->getNativeType();
-
-            if ($nativeType) {
-                $nativeType->isSatisfiedBy(function (Type $type) use (&$targetClass): bool {
-                    return $type instanceof ObjectType && $this->resourceClassResolver->isResourceClass($targetClass = $type->getClassName());
-                });
-            }
-
-            if (null === $targetClass) {
-                throw new ItemNotFoundException(\sprintf('Cannot determine target class for property "%s".', $attributeName));
-            }
-
             /** @var HttpOperation $getOperation */
-            $getOperation = $this->resourceMetadataCollectionFactory->create($targetClass)->getOperation(httpOperation: true);
-            $iri = $this->reconstructIri($targetClass, (string) $value['id'], $getOperation);
+            $getOperation = $this->resourceMetadataCollectionFactory->create($className)->getOperation(httpOperation: true);
+            $iri = $this->reconstructIri($className, (string) $value['id'], $getOperation);
 
             return $this->iriConverter->getResourceFromIri($iri, $context);
         } catch (ItemNotFoundException $e) {

src/JsonApi/Tests/Serializer/ItemNormalizerTest.php

@@ -314,6 +314,67 @@ public function testDenormalize(): void
         $this->assertInstanceOf(Dummy::class, $normalizer->denormalize($data, Dummy::class, ItemNormalizer::FORMAT));
     }
 
+    // https://github.com/api-platform/core/pull/7938
+    public function testDenormalizeRelationUsesClassNameArgument(): void
+    {
+        $relatedDummy = new RelatedDummy();
+        $relatedDummy->setId(1);
+
+        $propertyMetadata = (new ApiProperty())
+            ->withNativeType(Type::collection(Type::object(ArrayCollection::class), Type::object(RelatedDummy::class), Type::int()))
+            ->withReadable(false)->withWritable(true)
+            ->withReadableLink(false)->withWritableLink(false);
+
+        $iriConverter = $this->createStub(IriConverterInterface::class);
+        $iriConverter->method('getIriFromResource')->willReturn('/related_dummies/1');
+        $iriConverter->method('getResourceFromIri')->willReturn($relatedDummy);
+
+        $resourceClassResolver = $this->createStub(ResourceClassResolverInterface::class);
+        $resourceClassResolver->method('isResourceClass')->willReturnMap([
+            [RelatedDummy::class, true],
+            [ArrayCollection::class, false],
+        ]);
+
+        $resourceMetadataCollectionFactory = $this->createMock(ResourceMetadataCollectionFactoryInterface::class);
+        $resourceMetadataCollectionFactory->expects($this->once())
+            ->method('create')
+            ->with(RelatedDummy::class)
+            ->willReturn(new ResourceMetadataCollection(RelatedDummy::class, [
+                (new ApiResource())->withOperations(new Operations([
+                    new Get(name: 'get', uriTemplate: '/related_dummies/{id}', uriVariables: ['id' => new Link(fromClass: RelatedDummy::class, identifiers: ['id'])]),
+                ])),
+            ]));
+
+        $normalizer = new ItemNormalizer(
+            $this->createStub(PropertyNameCollectionFactoryInterface::class),
+            $this->createStub(PropertyMetadataFactoryInterface::class),
+            $iriConverter,
+            $resourceClassResolver,
+            null,
+            new ReservedAttributeNameConverter(),
+            null,
+            [],
+            $resourceMetadataCollectionFactory,
+            null,
+            null,
+            null,
+            null,
+            false,
+        );
+
+        $result = (new \ReflectionMethod(ItemNormalizer::class, 'denormalizeRelation'))->invoke(
+            $normalizer,
+            'relatedDummies',
+            $propertyMetadata,
+            RelatedDummy::class,
+            ['type' => 'related-dummy', 'id' => '1'],
+            null,
+            []
+        );
+
+        $this->assertSame($relatedDummy, $result);
+    }
+
     public function testDenormalizeUpdateOperationNotAllowed(): void
     {
         $this->expectException(NotNormalizableValueException::class);