MappingException on loadFixtures in the Codeception tests

Question

I use the PHP Codeception framework to work with integration tests in the PHP app. Having mongodb as a main db, I use https://codeception.com/docs/modules/Doctrine2 extension to loadFixtures in the test.

It looks like this:

class TestExampleCest
{
    public function setUp(IntegrationTester $i): void
    {
        $i->loadFixtures(TestFixtures::class);
    }
....
}

class TestFixtures extends Fixture
{
    public function load(ObjectManager $manager): void
    {
      $object = new Ob();
      $manager->persist($object);
      $manager->flush();
    }
}

Fixtures work perfectly, when I run the command to load them manually:

php bin/console --env=test doctrine:mongodb:fixtures:load

Some basic fixtures I load before all tests and some on runtime in particular tests. Unfortunately, loading on runtime in the setUp method doesn't work. I am getting:

[ModuleException] Doctrine2: Fixtures could not be loaded, got Doctrine\Persistence\Mapping\MappingException: The class 'App\Ob' was not found in the chain configured namespaces

Can anybody help? Maybe it's a problem with mappings for tests.. I can't figure out it.

---

Solution -> workaround

The problem can be solved by adding a custom function to load fixture and skipping using a plugin. I wrote a loadFixture function in the Integration class helper:

public function loadFixture(object $fixture): void
{
    $container = $this->getModule('Symfony')->_getContainer();
    $documentManager = $container->get('doctrine_mongodb.odm.default_document_manager');

    $loader = new Loader();
    $loader->addFixture($fixture);
    $executor = new MongoDBExecutor(
        $documentManager,
        new MongoDBPurger()
    );

    $executor->execute($loader->getFixtures(), true);
}