proper way to test a service in Symfony 4, with database access - unit-testing

Question

What would be the proper way to test a service in Symfony 4, which also accesses the database?
I am new in Symfony4 (before I developed for Symfony2) and I want to write my first test for a Service.
This service is writing via Entities / Doctrine / ORM in the database and each of my methods, I want to test is triggering a database save.
In Symfony 2 this was the case when I used rather KernelTestCase instead of the PHPUnit_Framework_TestCase because mocking the EntityManager was a pain in the ass and often I also wanted to check the result in the test db.
All examples for Symfony 4 only mention the KernelTestCase for testing Commands.
My class:
class UserPropertyService implements UserPropertyServiceInterface
{
public function __construct(EntityManager $em, LoggerInterface $logger)
{
....
}
....
}
My attempt at a Test:
class UserPropertyServiceTest extends KernelTestCase
{
/** #var UserPropertyService */
private $userPropertyService;
public function setUp()
{
self::bootKernel();
$client = static::createClient();
$container = $client->getContainer();
$this->userPropertyService = self::$container->get('app.user_management.user_property_service');
}
results in:
Cannot autowire service "App\Service\UserManagement\UserPropertyService": argument
"$em" of method "__construct()" references class "Doctrine\ORM\EntityManager"
but no such service exists.
Try changing the type-hint to one of its parents: interface "Doctrine\ORM\EntityManagerInterface",
or interface "Doctrine\Common\Persistence\ObjectManager".
What is the proper approach here? Which test class should I use?

Answer 1

This is how look like a service test (do not get your Container through the client, those containers are different)
By the way, you can't use static::createClient(); if you extend from KernelTestCase (misunderstanding with controller test and the WebTestCase class ?)
<?php
namespace App\Tests\Service;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
class UserPropertyServiceTest extends KernelTestCase
{
/** #var UserPropertyService */
private $myService;
public function setUp() {
self::bootKernel();
$this->myService = self::$kernel->getContainer()->get('app.user_management.user_property_service');
}
}