[FIXED] @Version field in entity class not increased during JPA test even though I updated it

Issue

I have a simple Repository:

public interface ReviewRepository extends CrudRepository<ReviewEntity, Integer> {

  @Transactional(readOnly = true)
  List<ReviewEntity> findByProductId(int productId);
}

I want to test it using test containers I followed the procedures and wrote my test case:

public abstract class MySqlTestBase {
  private static MySQLContainer database = new MySQLContainer("mysql:5.7.32");

  static {
    database.start();
  }

  @DynamicPropertySource
  static void databaseProperties(DynamicPropertyRegistry registry) {
    registry.add("spring.datasource.url", database::getJdbcUrl);
    registry.add("spring.datasource.username", database::getUsername);
    registry.add("spring.datasource.password", database::getPassword);
  }

}



@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
class PersistTests extends MySqlTestBase {

  @Autowired
  private ReviewRepository repository;

  private ReviewEntity savedEntity;

  @BeforeEach
  void setupDb() {
    repository.deleteAll();

    ReviewEntity entity = new ReviewEntity(1, 2, "author1");
    savedEntity = repository.save(entity);
    assertEqualsReview(entity, savedEntity);
  }

  @Test
  void update() {
    savedEntity.setAuthor("author2");
    repository.save(savedEntity);



       ReviewEntity foundEntity = repository.findById(savedEntity.getId()).get();
       assertEquals(1, (long)foundEntity.getVersion());
       assertEquals("author2", foundEntity.getAuthor());
          }
    }

my ReviewEntity also is written like:

@Entity
public class ReviewEntity {

  @Id @GeneratedValue
  private int id;

  @Version
  private int version;

  private int productId;
  private int reviewId;
  private String author;

  public ReviewEntity(int productId, int reviewId, String author) {
        this.productId = productId;
        this.reviewId = reviewId;
        this.author = author;
}

          // setter and getter
    
    }

When I run this test it fails at the assertEquals(1, (long)foundEntity.getVersion()); line with this message:

expected: <1> but was: <0>
Expected :1
Actual   :0

But I update the ReviewEntity class and according to the documentation the @Version field should automatically increases but this not happens. what part of my test is wrong?

Solution

If you look at the default implementation of save method in CrudRepository interface in the SimpleJpaRepository class you will see save method is implemented like:

@Transactional
@Override
public <S extends T> List<S> saveAll(Iterable<S> entities) {

    Assert.notNull(entities, "Entities must not be null!");

    List<S> result = new ArrayList<S>();

    for (S entity : entities) {
        result.add(save(entity));
    }

    return result;
}

meaning it is marked with @Transactional with Required as its propagation level(it is default)

Required propagation works like this:

REQUIRED is the default propagation. Spring checks if there is an active transaction, and if nothing exists, it creates a new one. Otherwise, the business logic appends to the currently active transaction

and for DataJpaTest annotation comment section says:

By default, tests annotated with @DataJpaTest are transactional and roll back at the end of each test

So for method update in your test a transaction is going to be created and the save method in repository.save(savedEntity); is going to be appended to that transaction. meaning it is committed only if that transaction successfully committed and we now know that's not going to happen.

A workaround for this problem probably would be to annotate test class with @Transactional(propagation = NOT_SUPPORTED) to suspends the currently running transaction then for repository.save(savedEntity); a transaction is going to be created and committed at the end of save method and then you can proceed in your test.

Answered By - h.a.
Answer Checked By - Clifford M. (JavaFixing Volunteer)