Add integration tests for entity manager merge return

Author: lcobucci

tests/DoctrineIntegration/ORM/EntityManagerIntegrationTest.php

@@ -15,6 +15,7 @@ public function dataTopics(): array
 		return [
 			['entityManagerDynamicReturn'],
 			['entityRepositoryDynamicReturn'],
+			['entityManagerMergeReturn'],
 		];
 	}
 

tests/DoctrineIntegration/ORM/data/entityManagerMergeReturn.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\DoctrineIntegration\ORM\EntityManagerMergeReturn;
+
+use Doctrine\ORM\EntityManagerInterface;
+
+class Example
+{
+	/**
+	 * @var EntityManagerInterface
+	 */
+	private $entityManager;
+
+	public function __construct(EntityManagerInterface $entityManager)
+	{
+		$this->entityManager = $entityManager;
+	}
+
+	public function merge(): void
+	{
+		$test = $this->entityManager->merge(new MyEntity());
+		$test->doSomething();
+	}
+}
+
+/**
+ * @ORM\Entity()
+ */
+class MyEntity
+{
+	public function doSomething(): void
+	{
+	}
+}