Fix for failing doctrine object constructor on embeddable class

src/Construction/DoctrineObjectConstructor.php

@@ -89,6 +89,12 @@ public function construct(DeserializationVisitorInterface $visitor, ClassMetadat
             $identifierList[$name] = $data[$dataName];
         }
 
+        if (empty($identifierList)) {
+            // $classMetadataFactory->isTransient() fails on embeddable class with file metadata driver
+            // https://github.com/doctrine/persistence/issues/37
+            return $this->fallbackConstructor->construct($visitor, $metadata, $data, $type, $context);
+        }
+
         // Entity update, load it from database
         $object = $objectManager->find($metadata->name, $identifierList);
 

tests/Fixtures/Doctrine/XmlMapping/JMS.Serializer.Tests.Fixtures.Doctrine.Embeddable.BlogPostSeo.dcm.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xsi="http://www.w3.org/2001/XMLSchema-instance" schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
+  <embeddable name="JMS\Serializer\Tests\Fixtures\Doctrine\Embeddable\BlogPostSeo">
+    <field name="metaTitle" column="meta_title" type="string" nullable="false"/>
+  </embeddable>
+</doctrine-mapping>

tests/Serializer/Doctrine/ObjectConstructorTest.php

@@ -14,9 +14,11 @@
 use Doctrine\ORM\Configuration;
 use Doctrine\ORM\EntityManager;
 use Doctrine\ORM\Mapping\Driver\AnnotationDriver;
+use Doctrine\ORM\Mapping\Driver\XmlDriver;
 use Doctrine\ORM\ORMException;
 use Doctrine\ORM\Tools\SchemaTool;
 use Doctrine\ORM\UnitOfWork;
+use Doctrine\ORM\Version as ORMVersion;
 use JMS\Serializer\Builder\CallbackDriverFactory;
 use JMS\Serializer\Builder\DefaultDriverFactory;
 use JMS\Serializer\Construction\DoctrineObjectConstructor;
@@ -29,6 +31,7 @@
 use JMS\Serializer\Serializer;
 use JMS\Serializer\SerializerBuilder;
 use JMS\Serializer\SerializerInterface;
+use JMS\Serializer\Tests\Fixtures\Doctrine\Embeddable\BlogPostSeo;
 use JMS\Serializer\Tests\Fixtures\Doctrine\Entity\Author;
 use JMS\Serializer\Tests\Fixtures\Doctrine\IdentityFields\Server;
 use JMS\Serializer\Tests\Fixtures\DoctrinePHPCR\Author as DoctrinePHPCRAuthor;
@@ -212,6 +215,40 @@ public function testNamingForIdentifierColumnIsConsidered()
         );
     }
 
+    public function testFallbackOnEmbeddableClassWithXmlDriver()
+    {
+        if (ORMVersion::compare('2.5') >= 0) {
+            $this->markTestSkipped('Not using Doctrine ORM >= 2.5 with Embedded entities');
+        }
+
+        $fallback = $this->getMockBuilder(ObjectConstructorInterface::class)->getMock();
+        $fallback->expects($this->once())->method('construct');
+
+        $connection = $this->createConnection();
+        $entityManager = $this->createXmlEntityManager($connection);
+
+        $this->registry = $registry = new SimpleBaseManagerRegistry(
+            static function ($id) use ($connection, $entityManager) {
+                switch ($id) {
+                    case 'default_connection':
+                        return $connection;
+
+                    case 'default_manager':
+                        return $entityManager;
+
+                    default:
+                        throw new \RuntimeException(sprintf('Unknown service id "%s".', $id));
+                }
+            }
+        );
+
+        $type = ['name' => BlogPostSeo::class, 'params' => []];
+        $class = new ClassMetadata(BlogPostSeo::class);
+
+        $constructor = new DoctrineObjectConstructor($this->registry, $fallback, DoctrineObjectConstructor::ON_MISSING_FALLBACK);
+        $constructor->construct($this->visitor, $class, ['metaTitle' => 'test'], $type, $this->context);
+    }
+
     protected function setUp()
     {
         $this->visitor = $this->getMockBuilder(DeserializationVisitorInterface::class)->getMock();
@@ -265,20 +302,38 @@ private function createConnection()
         ]);
     }
 
-    private function createEntityManager(Connection $con)
+    private function createEntityManager(Connection $con, ?Configuration $cfg = null)
     {
-        $cfg = new Configuration();
-        $cfg->setMetadataDriverImpl(new AnnotationDriver(new AnnotationReader(), [
-            __DIR__ . '/../../Fixtures/Doctrine/Entity',
-            __DIR__ . '/../../Fixtures/Doctrine/IdentityFields',
-        ]));
+        if (!$cfg) {
+            $cfg = new Configuration();
+            $cfg->setMetadataDriverImpl(new AnnotationDriver(new AnnotationReader(), [
+                __DIR__ . '/../../Fixtures/Doctrine/Entity',
+                __DIR__ . '/../../Fixtures/Doctrine/IdentityFields',
+            ]));
+        }
+
         $cfg->setAutoGenerateProxyClasses(true);
         $cfg->setProxyNamespace('JMS\Serializer\DoctrineProxy');
         $cfg->setProxyDir(sys_get_temp_dir() . '/serializer-test-proxies');
 
         return EntityManager::create($con, $cfg);
     }
 
+    /**
+     * @param Connection $con
+     *
+     * @return EntityManager
+     */
+    private function createXmlEntityManager(Connection $con)
+    {
+        $cfg = new Configuration();
+        $cfg->setMetadataDriverImpl(new XmlDriver([
+            __DIR__ . '/../../Fixtures/Doctrine/XmlMapping',
+        ]));
+
+        return $this->createEntityManager($con, $cfg);
+    }
+
     /**
      * @return SerializerInterface
      */