We can unify the launchers by accepting a BooksEndpoint dependency. If we don't specify it, it will register the dependency with the real instance of BooksRepository. Otherwise, it will register the received one:

public class MyApplication 
      extends ResourceConfig { 
 
    public MyApplication() { 
        this(new BooksEndpoint( 
          new BooksRepository())); 
    } 
 
    public MyApplication 
      (BooksEndpoint booksEndpoint) { 
        register(booksEndpoint); 
        register(RequestContextFilter.class); 
        register(JacksonJaxbJsonProvider.class); 
        register(CustomExceptionMapper.class); 
    } 
} 

In this case, we have opted for constructor chaining to avoid repetition in the constructors.

After doing this refactor, the BooksEndpointInteractionTest class is as follows
in its final state:

public class BooksEndpointInteractionTest { 
 
    public static final URI FULL_PATH = URI. 
        create("http://localhost:8080/alexandria"); 
    private HttpServer server; 
    private BooksRepository booksRepository; 
 
    @Before 
    public void setUp() throws IOException { 
        booksRepository = mock(BooksRepository.class); 
        BooksEndpoint booksEndpoint = 
          new BooksEndpoint(booksRepository); 
        ResourceConfig resourceConfig = 
          new MyApplication(booksEndpoint); 
        server = GrizzlyHttpServerFactory 
           .createHttpServer(FULL_PATH, resourceConfig); 
        server.start(); 
    } 

The first test passed, so we can mark the dependency injection task as done.

Tasks performed:

• Dependency injection in BooksEndpoint for books

The to-do list:

• Change status for statuses
• Remove the primitive obsession with status (optional)