Spring Boot Service Junit Mockito issue - spring-boot

Question

I have written Junit for the service. mocking dao.
Service method return type in EmployeeDTO.
Dao return type is Employee.
problem is employee to employeeDto conversion failed in test case.
when(dao.method()).thenReturn(new Employee), so on call od service.method() I am facing issue since dozer is in between to convert employee to employeedto in the actual code.
any suggestions to fix this.
#SpringBootTest(classes = { EmployeeSearchService.class, EmployeeDao.class })
public class EmployeeSearchServiceTest {
#Mock // will create a mock implementation for the EmployeeDao
EmployeeDao employeeDao;
#InjectMocks // will inject the mocks marked with #Mock to this instance when it is created.
private EmployeeSearchService employeeSearchService ;
#Mock
private DozerBeanMapper dozerBeanMapper;
#Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
}
#DisplayName("fetchEmployees with valid data")
#Test
public void testfetchEmployeesWithValidData() throws IOException {
when(employeeDao.fetchEmployees()).thenReturn(Stream
.of(new Employee((long) 1, "James", "Java", "Manager", "Google"),
new Employee((long) 2, "Richard", "C++", "Manager", "Microsfot"))
.collect(Collectors.toList()));
//when(dozer.map(Mockito.any(), Mockito.any())).thenReturn(employeeDTO);
System.out.println(employeeSearchService.fetchEmployees());
assertEquals(4, employeeSearchService.fetchEmployees().size());
}
}
#Service
public class EmployeeSearchServiceImpl implements EmployeeSearchService {
#Autowired
EmployeeDao employeeDao;
#Autowired
DozerBeanMapper dozerBeanMapper;
#Override
#Logging
public List<EmployeeDTO> fetchEmployees() throws IOException {
List<Employee> aEmployeeList = employeeDao.fetchEmployees();
List<EmployeeDTO> aEmployeeDTOList= aEmployeeList.stream().map(emp ->
dozerBeanMapper.map(emp,
EmployeeDTO.class)).collect(Collectors.toList());
if (aEmployeeList.isEmpty()) {
throw new EmployeeNotfoundException("Employee Details Not Available");
}
return aEmployeeDTOList;
}
}
#Repository
public class EmployeeDaoImpl implements EmployeeDao {
#Override
#Logging
public List<Employee> fetchEmployees() throws IOException {
List<String> aFileList=fileUtils.getFileContent(EmployeeSearchConstants.EMPLOYEE_DETAILS_PATH);
List<Employee> aEmployeList = getEmployee(aFileList);
if (aEmployeList.isEmpty()) {
throw new EmployeeNotfoundException("Employee Details Not Available");
}
return aEmployeList;
}
}

Answer 1

If I understand you correctly your issue is that you are looking for a way to convert your Employee into a EmployeeDTO object, which in your code is done using dozerBeanMapper.map(emp, EmployeeDTO.class).
One option would be to change the EmployeeSearchServiceImpl and use Constructor Injection instead of Field Injection. This way you could simply use the real dozer class to do the mapping (by manually passing the mock for employeeDao and the real dozerBeanMapper).
Constructor Injection is done by moving the #Autowired to the constructor instead of the fields. Depening on your spring version and in case you only have one constructor for the class you might be able to omit the annotation. For more information check here.
EmployeeDao employeeDao;
DozerBeanMapper dozerBeanMapper;
#Autowired
public EmployeeSearchServiceImpl(EmployeeDao employeeDao, DozerBeanMapper dozerBeanMapper) {
this.employeeDao = employeeDao;
this.dozerBeanMapper = dozerBeanMapper;
}
Another option would be to use Mockito's thenAnser functionality. However
you still require something to do the conversion for you.
when(dozerBeanMapper.map(Mockito.any(), Mockito.any())).thenAnswer(new Answer<EmployeeDTO>() {
public EmployeeDTO answer(InvocationOnMock invocation) {
Employee employee = (Employee) invocation.getArguments()[0];
// convert to EmployeeDTO
EmployeeDTO dto = ...
return dto;
}
});