How can I test Spring applications using dependency injection?

How can I test Spring applications using dependency injection?

You can test Spring applications by using the Spring Test framework, which supports dependency injection for your tests.

What are some best practices for setting up tests with dependency injection?

Some best practices include using @MockBean for mocking dependencies, keeping tests isolated, and using @SpringBootTest for integration tests.

Can you give me an example of a test case using JUnit and Mockito?

Sure! Here's a simple example:

@RunWith(SpringRunner.class)
@SpringBootTest
public class MyServiceTest {

    @MockBean
    private MyRepository myRepository;

    @Autowired
    private MyService myService;

    @Test
    public void testServiceMethod() {
        // Arrange
        when(myRepository.findById(1)).thenReturn(Optional.of(new MyEntity()));

        // Act
        MyEntity result = myService.getEntityById(1);

        // Assert
        assertNotNull(result);
    }
}

What libraries do I need to include for testing?

You will need JUnit, Mockito, and Spring Test dependencies in your pom.xml or build.gradle file.