What @WebMvcTest Excludes

Direct Answer

@WebMvcTest limits component scanning to MVC-related types and does not discover ordinary service or repository beans. It does include supported web infrastructure such as controllers, advice, converters, filters, and security configuration types. Supply a controller dependency with @MockitoBean (or older @MockBean) or import a small real configuration when that is what the test needs.

Code Example

@WebMvcTest(UserController.class)
class UserControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private UserService userService; // Service not loaded, must mock

    @MockBean
    private EmailNotificationService emailService; // Another dependency

    @Test
    void shouldCreateUserSuccessfully() throws Exception {
        var newUser = new User(null, "alice@example.com");
        var savedUser = new User(10L, "alice@example.com");
        
        when(userService.createUser(any(User.class))).thenReturn(savedUser);

        mockMvc.perform(post("/api/users")
               .contentType(MediaType.APPLICATION_JSON)
               .content("{\"email\":\"alice@example.com\"}"))
               .andExpect(status().isCreated())
               .andExpect(jsonPath("$.id").value(10));
    }
}

Common Mistakes & Pitfalls

• Treating the slice as an exact bean whitelist: Imports and supported web configuration types can add beans beyond the selected controller.
• Using a fixed dependency-count rule: The design problem is unclear responsibilities, not a universal maximum number.
• Disabling security to make the test green: If security is part of the public behavior, model an authenticated or unauthenticated request and assert the expected result.