I am trying to unit test my bundle and I want to get unit of work from EventManager Mock. Basically, I want to get the last persisted object. I know in normal application, I can do the same with a EventSubscriber.
What I want to achieve is basically, check status of previous persisted record if its flag is pending, then in next persist, I want to update it to not pending.
Example:
Here's how I get Event Manager:
/**
 * @param Entity\Friend|null $friendEntity
 * @return \Doctrine\ORM\EntityManager|\PHPUnit_Framework_MockObject_MockObject
 */
private function getEntityManager(Entity\Friend $friendEntity = null)
{
    $repository = $this
        ->getMockBuilder('\Doctrine\ORM\EntityRepository')
        ->disableOriginalConstructor()
        ->setMethods(['findBy'])
        ->getMock();
    $repository
        ->expects($this->any())
        ->method('findBy')
        ->will($this->returnValue(null));
    /** @var \Doctrine\ORM\EntityManager|\PHPUnit_Framework_MockObject_MockObject $entityManager */
    $entityManager = $this
        ->getMockBuilder('\Doctrine\ORM\EntityManager')
        ->setMethods(['getRepository', 'getUnitOfWork', 'persist'])
        ->disableOriginalConstructor()
        ->getMock();
    $entityManager
        ->expects($this->any())
        ->method('getRepository')
        ->will($this->returnValue($repository));
    $entityManager
        ->expects($this->any())
        ->method('getUnitOfWork')
        ->will($this->returnValue($repository));
    $entityManager
        ->expects($this->any())
        ->method('persist')
        ->with($friendEntity)
        ->will($this->returnValue(null));
    return $entityManager;
}
And in my test:
/**
 * Test add friend when friend pending
 */
public function testAddFriendPending()
{
    $friendEntity = new Entity\Friend($this->friend, $this->user);
    $entityManager = $this->getEntityManager($friendEntity);
    $pendingRequest = new FriendService($entityManager);
    /** @var Entity\Friend $lastInsert */
    $lastInsert = $pendingRequest->addFriend($this->friend, $this->user);
    $lastInsert->setId(1);
    $friendAddRequest = new FriendService($entityManager);
    $friendAddRequest->addFriend($this->user, $this->friend);
    $response = $friendAddRequest->getStatus();
    $this->assertEquals(Entity\Friend::FRIEND_ADD_STATUS_COMPLETED, $response);
}
EDIT
Still receiving errors:
vendor/phpunit/phpunit/phpunit src/NalabTnahsarp/FriendFollowerBundle/Tests/Service/
PHPUnit 5.7.21 by Sebastian Bergmann and contributors.
EE                                                                  2 / 2 (100%)
Time: 102 ms, Memory: 4.00MB
There were 2 errors:
1) NalabTnahsarp\FriendFollowerBundle\Tests\Service\FriendTest::testAddFriendNotPending
Error: Call to a member function getUnitOfWork() on null
/Users/Sites/app/vendor/doctrine/orm/lib/Doctrine/ORM/EntityRepository.php:194
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Service/Friend.php:140
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Service/Friend.php:63
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Tests/Service/FriendTest.php:43
2) NalabTnahsarp\FriendFollowerBundle\Tests\Service\FriendTest::testAddFriendPending
Error: Call to a member function getUnitOfWork() on null
/Users/Sites/app/vendor/doctrine/orm/lib/Doctrine/ORM/EntityRepository.php:194
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Service/Friend.php:140
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Service/Friend.php:63
/Users/Sites/app/src/NalabTnahsarp/FriendFollowerBundle/Tests/Service/FriendTest.php:57