Symfony testing repository custom method

I am trying to test a custom repository function but when my test call the function I have this error “BadMethodCallException: Undefined method “getByState”. I don’t understand why. The repository seems to be empty of my custom functions.
Maybe it’s because the Document entity is declared as an abstract class…
I also have tests on another repository which are perfectly running.

Entity/Document.php

#[Entity(repositoryClass: DocumentRepository::class)]
#[InheritanceType('JOINED')]
abstract class Document
{
...
}

tests/DocumentRepositoryTest.php

<?php

namespace AppTest;

use AppEntityDocument;
use AppRepositoryDocumentRepository;
use AppWorkflowStateDocumentWorkflowState;
use DoctrineORMEntityManager;
use SymfonyBundleFrameworkBundleTestKernelTestCase;

class DocumentRepositoryTest extends KernelTestCase
{

    private ?EntityManager $entityManager;

    protected function setUp(): void
    {
        $kernel = self::bootKernel();

        $this->entityManager = $kernel->getContainer()
            ->get('doctrine')
            ->getManager();
    }

    protected function tearDown(): void
    {
        parent::tearDown();

        $this->entityManager->close();
        $this->entityManager = null;
    }
    public function testGetByState(): void
    {
        /** @var DocumentRepository */
        $documentRepository = $this->entityManager
            ->getRepository(Document::class);

        assert($documentRepository instanceof DocumentRepository);

        $documents = $documentRepository->getByState(DocumentWorkflowState::BROUILLON);

        foreach ($documents as $document) {
            $this->assertEquals(DocumentWorkflowState::BROUILLON, $document->getState(), 'Erreur dans la fonction findByStatus');
        }
    }
}

Repository/DocumentRepository.php

<?php

namespace AppRepository;

use AppEntityDocument;
use DoctrineBundleDoctrineBundleRepositoryServiceEntityRepository;

/**
 * @extends ServiceEntityRepository<Document>
 *
 * @method Document|null find($id, $lockMode = null, $lockVersion = null)
 * @method Document|null findOneBy(array $criteria, array $orderBy = null)
 * @method Document[]    findAll()
 * @method Document[]    findBy(array $criteria, array $orderBy = null, $limit = null, $offset = null)
 */
class DocumentRepository extends ServiceEntityRepository
{
/**
     * @return Document[] Returns an array of Jury objects
     */
    public function getByState(string $state): array
    {
        return $this->createQueryBuilder('d')
            ->leftJoin('d.statuses', 'statuses')
            ->where(
                ":val = (SELECT st.status FROM AppEntityStatus st
                                WHERE st.id = (SELECT MAX(s.id) FROM AppEntityStatus s
                                WHERE s.document = d
                                GROUP BY s.document)
                    )"
            )
            ->setParameter('val', $state)
            ->orderBy('d.libelle_etape', 'ASC')
            ->getQuery()
            ->getResult();
    }
}

Thanks for ideas !