Allow DataPersister to return a new instance instead of mutating

see : #1799

Author: Rodrigue Villetard

src/Bridge/Doctrine/Common/DataPersister.php

@@ -48,7 +48,7 @@ public function supports($data): bool
     public function persist($data)
     {
         if (!$manager = $this->getManager($data)) {
-            return;
+            return $data;
         }
 
         if (!$manager->contains($data)) {
@@ -57,6 +57,8 @@ public function persist($data)
 
         $manager->flush();
         $manager->refresh($data);
+
+        return $data;
     }
 
     /**

src/Bridge/Doctrine/EventListener/WriteListener.php

@@ -58,7 +58,9 @@ public function onKernelView(GetResponseForControllerResultEvent $event)
 
         switch ($request->getMethod()) {
             case 'POST':
-                $objectManager->persist($controllerResult);
+                $event->setControllerResult(
+                    $objectManager->persist($controllerResult) ?? $controllerResult
+                );
                 break;
             case 'DELETE':
                 $objectManager->remove($controllerResult);

src/DataPersister/ChainDataPersister.php

@@ -51,7 +51,7 @@ public function persist($data)
     {
         foreach ($this->persisters as $persister) {
             if ($persister->supports($data)) {
-                $persister->persist($data);
+                return $persister->persist($data) ?? $data;
             }
         }
     }

src/DataPersister/DataPersisterInterface.php

@@ -33,6 +33,8 @@ 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);
 

src/EventListener/WriteListener.php

@@ -50,7 +50,10 @@ public function onKernelView(GetResponseForControllerResultEvent $event)
             case 'PUT':
             case 'PATCH':
             case 'POST':
-                $this->dataPersister->persist($controllerResult);
+                $event->setControllerResult(
+                    $this->dataPersister->persist($controllerResult)
+                    ?? $controllerResult
+                );
                 break;
             case 'DELETE':
                 $this->dataPersister->remove($controllerResult);

src/GraphQl/Resolver/Factory/ItemMutationResolverFactory.php

@@ -93,9 +93,9 @@ public function __invoke(string $resourceClass = null, string $rootClass = null,
                     $context += $resourceMetadata->getGraphqlAttribute($operationName, 'denormalization_context', [], true);
                     $item = $this->normalizer->denormalize($args['input'], $resourceClass, ItemNormalizer::FORMAT, $context);
                     $this->validate($item, $info, $resourceMetadata, $operationName);
-                    $this->dataPersister->persist($item);
+                    $persistResult = $this->dataPersister->persist($item) ?? $item;
 
-                    return $this->normalizer->normalize($item, ItemNormalizer::FORMAT, $normalizationContext) + $data;
+                    return $this->normalizer->normalize($persistResult, ItemNormalizer::FORMAT, $normalizationContext) + $data;
                 case 'delete':
                     if ($item) {
                         $this->dataPersister->remove($item);

tests/Bridge/Doctrine/Common/DataPersisterTest.php

@@ -56,7 +56,8 @@ public function testPersist()
         $managerRegistryProphecy = $this->prophesize(ManagerRegistry::class);
         $managerRegistryProphecy->getManagerForClass(Dummy::class)->willReturn($objectManagerProphecy->reveal())->shouldBeCalled();
 
-        (new DataPersister($managerRegistryProphecy->reveal()))->persist($dummy);
+        $result = (new DataPersister($managerRegistryProphecy->reveal()))->persist($dummy);
+        $this->assertSame($dummy, $result);
     }
 
     public function testPersistIfEntityAlreadyManaged()
@@ -72,15 +73,19 @@ public function testPersistIfEntityAlreadyManaged()
         $managerRegistryProphecy = $this->prophesize(ManagerRegistry::class);
         $managerRegistryProphecy->getManagerForClass(Dummy::class)->willReturn($objectManagerProphecy->reveal())->shouldBeCalled();
 
-        (new DataPersister($managerRegistryProphecy->reveal()))->persist($dummy);
+        $result = (new DataPersister($managerRegistryProphecy->reveal()))->persist($dummy);
+        $this->assertSame($dummy, $result);
     }
 
     public function testPersistWithNullManager()
     {
+        $dummy = new Dummy();
+
         $managerRegistryProphecy = $this->prophesize(ManagerRegistry::class);
         $managerRegistryProphecy->getManagerForClass(Dummy::class)->willReturn(null)->shouldBeCalled();
 
-        (new DataPersister($managerRegistryProphecy->reveal()))->persist(new Dummy());
+        $result = (new DataPersister($managerRegistryProphecy->reveal()))->persist($dummy);
+        $this->assertSame($dummy, $result);
     }
 
     public function testRemove()

tests/EventListener/WriteListenerTest.php

@@ -49,6 +49,46 @@ public function testOnKernelViewWithControllerResultAndPersist()
             $request->setMethod($httpMethod);
 
             (new WriteListener($dataPersisterProphecy->reveal()))->onKernelView($event);
+            $this->assertSame($dummy, $event->getControllerResult());
+        }
+    }
+
+    /**
+     * @see https://github.com/api-platform/core/issues/1799
+     */
+    public function testOnKernelViewWithControllerResultAndPersistWithImmutableResource()
+    {
+        $dummy = new Dummy();
+        $dummy->setName('Dummyrino');
+
+        $dummy2 = new Dummy();
+        $dummy2->setName('Dummyferoce');
+
+        $dataPersisterProphecy = $this->prophesize(DataPersisterInterface::class);
+        $dataPersisterProphecy->supports($dummy)->willReturn(true)->shouldBeCalled();
+
+        $dataPersisterProphecy
+            ->persist($dummy)
+            ->willReturn($dummy2) // Persist is not mutating $dummy, but return a brand new technically unrelated object instead
+            ->shouldBeCalled()
+        ;
+
+        $request = new Request();
+        $request->attributes->set('_api_resource_class', Dummy::class);
+
+        foreach (['PATCH', 'PUT', 'POST'] as $httpMethod) {
+            $event = new GetResponseForControllerResultEvent(
+                $this->prophesize(HttpKernelInterface::class)->reveal(),
+                $request,
+                HttpKernelInterface::MASTER_REQUEST,
+                $dummy
+            );
+
+            $request->setMethod($httpMethod);
+
+            (new WriteListener($dataPersisterProphecy->reveal()))->onKernelView($event);
+
+            $this->assertSame($dummy2, $event->getControllerResult());
         }
     }