How can i make Testing in Spring boot when i have a Page<Object> as a return type

Question

I am trying to do testing my save method in my service impl class. It has Page as return type. The test succeeds but I am writting something wrong because it succeeds for all the cases which normally shouldn't Please see my code below.

Service Class Implementation

@Service
@Transactional
public class CompanyServiceImpl implements CompanyService {

    private final CompanyRepository companyRepository;

    public CompanyServiceImpl(CompanyRepository companyRepository) {
        this.companyRepository = companyRepository;
    }

    @Override
    public Page<Company> findAll(Pageable pageable) {
        Page<Company> result = companyRepository.findAll(pageable);
        return result;
    }

    @Override
    public Page<Company> searchCompany(String companyName, Long companyGroupId, Pageable pageable) {

        Page<Company> result = companyRepository.findByParametersWeb(companyName,companyGroupId,pageable);

        return result;
    }

    @Override
    public Optional<Company> findById(Long id) {
        Optional<Company> entity = companyRepository.findById(id);
        return entity;
    }

    @Override
    public Company save(Company company) {
        Company entity = companyRepository.save(company);
        return entity;
    }


    @Override
    public void delete(Long id) {
        companyRepository.deleteById(id);
    }
}

Testing Service class

class CompanyServiceImplTest {

    @Mock
    private CompanyRepository companyRepository;

    private CompanyService companyService;

    private Company company;


    @BeforeEach
    void setUp() {
        MockitoAnnotations.initMocks(this);
        companyService = new CompanyServiceImpl(companyRepository);

        company = new Company();
        company.setName("company");
        company.setCompanyGroupId(1L);
    }

    @Test
    void searchCompany() {

        List<Company> companies = new ArrayList<>();

        Pageable pageable= PageRequest.of(0,5);
        Page<Company> result = new PageImpl<>(companies,pageable,1);


        when(companyRepository.findByParametersWeb(anyString(),anyLong(),any(Pageable.class))).thenReturn(result);

        Page<Company> newResult = companyService.searchCompany("giorgos",1L,pageable);
        assertEquals(newResult.getTotalElements(),result.getTotalElements());

    }

}

Finally My Company Repository

@Repository
public interface CompanyRepository extends JpaRepository<Company, Long> {

    @Query("SELECT a FROM Company a WHERE (:name is null or ((a.name LIKE :name AND LENGTH(:name) > 0) OR ( a.name = '%')))")
    List<Company> findByCompanyName(@Param("name") String name);

    @Query("SELECT a FROM Company a WHERE (:name is null or (LENGTH(:name) > 0 " +
            " AND ((:option = 'yes' AND a.name = :name) or (:option = 'start' AND a.name LIKE CONCAT(:name,'%')) " +
            " or (:option = 'end' AND a.name LIKE CONCAT('%',:name)) or (a.name LIKE CONCAT('%',:name,'%'))))) " +
            " AND (:companyGroupId is null or a.companyGroupId = :companyGroupId) ORDER BY a.name")
    Page<Company> findByParametersWeb(String name,Long companyGroupId, Pageable pageable);

    List<Company> findAllByNameOrderByName();

}

Answer 1

So you want to differentiate unit tests from integration or component tests here. Your test would qualify as a unit test, it solely tests the functionality of your service layer isolated from everything else.
That is also why you mock your repository layer, to be independent from a database.

Contrary to that, integration and component tests test your whole application stack.
For this, the spring boot environment must be running, so you have to annotate your testclass with @ExtendWith(SpringExtension.class) .
For these kind of tests you need an active db, so commonly you use a h2 database for your tests, that is filled with data prior to your tests. Have a look at this and this .

In the test itself you either inject your service and test from there, or you call your endpoints using RestTemplate .

@ExtendWith(SpringExtension.class)
@SpringBootTest
@Sql("/schema.sql")
public class DocumentManagementBackendApplicationTest {

    @Autowired
    private final CompanyServiceImpl companyServiceImpl;

    @Test
    @Sql("/searchCompany.sql")
    public void testSearchCompany() {
        List<Company> companies = new ArrayList<>();

        Pageable pageable= PageRequest.of(0, 5);

        Page<Company> result = companyService.searchCompany("giorgos",1L,pageable);
        // now here you know, based on what you insert into your db with your sql scripts,
        // what you should expect and so you can test for it
        (...)
    }
}