I have a method named registerCustomer in a service implementation class. I created a test case named testRegisterCustomerSuccess for this method in a class named UserServiceImplTest, where I mock repositories and dependencies using Mockito:
@Mock
private UserRepository userRepository;
@Mock
private UserRoleRepository userRoleRepository;
@Mock
private CustomerRepository customerRepository;
@Mock
private PasswordEncoder passwordEncoder;
@BeforeEach
public void setUp() {
MockitoAnnotations.openMocks(this);
}
@Test
public void testRegisterCustomerSuccess() {
// Mock data
SignupRequest signupRequest = createSignupRequest();
when(userRepository.findByUsernameOrEmail(signupRequest.getEmail())).thenReturn(Optional.empty());
when(passwordEncoder.encode(signupRequest.getPassword())).thenReturn("encodedPassword");
when(userRepository.save(any(User.class))).thenAnswer(invocation -> {
User user = invocation.getArgument(0);
user.setId(1L); // Simulate saving in repository
return user;
});
when(userRoleRepository.save(any(UserRole.class))).thenAnswer(invocation -> {
UserRole role = invocation.getArgument(0);
role.setUserRoleId(1L); // Simulate saving in repository
return role;
});
when(customerRepository.save(any(Customer.class))).thenAnswer(invocation -> {
Customer customer = invocation.getArgument(0);
customer.setId(1L); // Simulate saving in repository
return customer;
});
// Call the service method
assertDoesNotThrow(() -> userService.registerCustomer(signupRequest));
// Verify interactions
verify(userRepository).findByUsernameOrEmail(signupRequest.getEmail());
verify(passwordEncoder).encode(signupRequest.getPassword());
verify(userRepository).save(any(User.class));
verify(userRoleRepository).save(any(UserRole.class));
verify(customerRepository).save(any(Customer.class));
}
But when the debugger reaches the corresponding point in the original service implementation method:
User savedUser = userRepository.save(user);
The savedUser object becomes null, causing a NullPointerException in the next line:
UserRole customerRole = new UserRole(savedUser.getId(), EnumUserRole.ROLE_CUSTOMER.name());
set savedUser = null so give me nullPointerException
This issue also occurs in all JPA repository methods like findAll, save, findByFieldName, etc. Could someone please provide a solution for unit and Mockito testing in a Spring Boot application?
