Spring Boot, Mockito, Unit Testing, Junit 5, Rest Api.
org.assertj.core.api.AssertionsForClassTypes.assertThat; import static org.mockito.ArgumentMatchers.any; import static org.mockito.ArgumentMatchers.anyString; import static org.mockito.Mockito.when; @ExtendWith(MockitoExtension.class) public class BookServiceTests { @Mock private BooksRepository