@MockBean for mocking dependencies in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mock a dependency using @MockBean in a Spring Boot test.

Spring Boot

@SpringBootTest
public class UserServiceTest {

    @[1]
    private UserRepository userRepository;

    @Autowired
    private UserService userService;

}

Drag options to blanks, or click blank then click option'

AService

BAutowired

CInjectMocks

DMockBean

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Autowired instead of @MockBean for mocking.

Confusing @InjectMocks with Spring annotations.

The @MockBean annotation is used to create and inject a mock of the UserRepository into the Spring test context.

2fill in blank

medium

Complete the code to define behavior for the mocked repository method.

Spring Boot

when(userRepository.[1](anyLong())).thenReturn(Optional.of(new User()));

Drag options to blanks, or click blank then click option'

Asave

BfindAll

CfindById

DdeleteById

Attempts:

3 left

💡 Hint

Common Mistakes

Using save or deleteById which do not return Optional.

Using findAll which returns a list, not Optional.

The findById method is used to fetch a user by ID, which is commonly mocked in tests.

3fill in blank

hard

Fix the error in the test annotation to enable Mockito support.

Spring Boot

@SpringBootTest
@[1]
public class ProductServiceTest {

    @MockBean
    private ProductRepository productRepository;

}

Drag options to blanks, or click blank then click option'

ARunWith(SpringRunner.class)

BExtendWith(MockitoExtension.class)

CEnableMocking

DMockitoTest

Attempts:

3 left

💡 Hint

Common Mistakes

Using MockitoExtension which is for pure Mockito tests, not Spring Boot tests.

Using non-existent annotations like EnableMocking.

The @RunWith(SpringRunner.class) annotation integrates Spring TestContext Framework with JUnit and enables Mockito support.

4fill in blank

hard

Fill both blanks to mock a service bean and inject it into the test class.

Spring Boot

@SpringBootTest
public class OrderServiceTest {

    @[1]
    private PaymentService paymentService;

    @Autowired
    private OrderService orderService;

    @Test
    public void testOrder() {
        when(paymentService.[2](anyDouble())).thenReturn(true);
    }
}

Drag options to blanks, or click blank then click option'

AMockBean

BAutowired

CprocessPayment

DcancelPayment

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Autowired instead of @MockBean for mocking.

Mocking the wrong method name.

Use @MockBean to mock PaymentService and define behavior for processPayment method.

5fill in blank

hard

Fill all three blanks to mock a repository, define a method behavior, and verify interaction.

Spring Boot

@SpringBootTest
public class CustomerServiceTest {

    @[1]
    private CustomerRepository customerRepository;

    @Autowired
    private CustomerService customerService;

    @Test
    public void testFindCustomer() {
        when(customerRepository.[2](anyString())).thenReturn(Optional.of(new Customer()));
        customerService.findCustomerByEmail("[e-mail]");
        verify(customerRepository).[3]("[e-mail]");
    }
}

Drag options to blanks, or click blank then click option'

AMockBean

BfindByEmail

Dsave

Attempts:

3 left

💡 Hint

Common Mistakes

Using save instead of findByEmail for mocking and verification.

Not using @MockBean for mocking the repository.

Use @MockBean to mock the repository, mock findByEmail method, and verify it was called with the email.