HS6, Testing and @Transactional

Hibernate Search
1

I wanted to test my research in my springboot + hibernate application.

In order to do that I used the in memory index for the test configuration.

hibernate.search.backend.directory.type                      = local-heap
hibernate.search.automatic_indexing.synchronization.strategy = sync

And then made a dummy test, who create and saveAndFlush an entity that I then search:

@Test
public void testSearchBook() {
    String ean = "000000000001";
    Book book = createBook(ean);
    bookDao.saveAndFlush(book);

    SearchFilterDto filter = new SearchFilterDto();
    filter.setEan(ean);

    List<Book> results = bookService.searchBook(filter);
    assertThat(results.size()).isEqualTo(1);
}

With all my test classes extending:

@RunWith(SpringRunner.class)
@SpringBootTest
@Transactional
public abstract class BaseServiceTest

And I couldn’t get the test working, I tried to delay the search expecting that the indexing wasn’t fast enought but it didn’t changed the outcome.

I finally found out that the problem came from the @Transactional annotation (javax.transaction.Transactional).
If I remove it globally or just for this test with @Transactional(TxType.NEVER) then the test pass sucessfully.

Does someone know what side effects of @Transactional cause the test to fail ?

2

When you make changes to your database in a transaction, indexing happens on commit. That’s actually a good thing, and generally what you want in production.

However, if you annotate your test with @Transactional, the commit happens at the end of the test method. Thus indexing won’t happen until after your test is finished, and you will never see the result of indexing.

Either:

  • Move the logic you want to test to a separate component (database changes in one method, search query in another), and annotate that component with @Transactional
  • Or use Spring’s TransactionTemplates to explicitly wrap your data changes in one transaction, and your search query in another transaction (after the changes have been committed).
3

Thank you for responding so quickly.
I knew indexing was on commit but I wrongly assumed that a flush would provoke said commit.

I will keep the global @Transactional annotation since I like the default rollback by Spring for all the tests who don’t rely on indexes.

Since the data’s creation and the search are already executed in their own separate transactions I just need to remove the one on the test method (added by the global annotation) with @Transactional(TxType.NEVER).

And as mentionned here adding on the test method @DirtiesContext(methodMode = MethodMode.AFTER_METHOD) also renew the test context emptying datas and indexes for the next tests.