What are some examples of unit testing in Spring Boot?

What are some examples of unit testing in Spring Boot?

In Spring Boot, unit testing can be done using JUnit and Mockito. For example, you can test a service class by mocking its dependencies.

Can you show me a simple example of a unit test for a service?

Sure! Here's a basic example:

@RunWith(MockitoJUnitRunner.class)
public class UserServiceTest {

    @InjectMocks
    private UserService userService;

    @Mock
    private UserRepository userRepository;

    @Test
    public void testFindUserById() {
        User user = new User(1L, "John Doe");
        Mockito.when(userRepository.findById(1L)).thenReturn(Optional.of(user));

        User found = userService.findUserById(1L);
        assertEquals("John Doe", found.getName());
    }
}

What about testing controllers?

For testing controllers, you can use MockMvc. Here's an example:

@RunWith(SpringRunner.class)
@WebMvcTest(UserController.class)
public class UserControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private UserService userService;

    @Test
    public void testGetUser() throws Exception {
        User user = new User(1L, "John Doe");
        Mockito.when(userService.findUserById(1L)).thenReturn(user);

        mockMvc.perform(get("/users/1"))
               .andExpect(status().isOk())
               .andExpect(jsonPath("$.name").value("John Doe"));
    }
}