1. We have the BookEndpoint.java:

package com.pluralsight.bookstore.rest;

import com.pluralsight.bookstore.model.Book;
import com.pluralsight.bookstore.repository.BookRepository;

import javax.inject.Inject;
import javax.validation.constraints.Min;
import javax.ws.rs.*;
import javax.ws.rs.core.Context;
 
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;

import java.net.URI;
import java.util.List;

import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
//api/books
@Path("/books")
public class BookEndpoint {

    @Inject
    private BookRepository bookRepository;

    @POST
    @Consumes(APPLICATION_JSON)
    
 
public Response createBook(Book book, @Context UriInfo uriInfo) {
        book =  bookRepository.create(book);
        URI createedURI = uriInfo.getBaseUriBuilder().path(book.getId().toString()).build();
        return Response.created(createedURI).build();
    }

    @GET
    @Produces(APPLICATION_JSON)
    
 
public Response getBooks() {
        List<Book> books = bookRepository.findAll();

        if(books.size() == 0) {
            return Response.noContent().build();
        }
        return Response.ok(books).build();
    }

    @GET
    @Path("/{id: \\d+}")
    @Produces(APPLICATION_JSON)
    public Response getBook(@PathParam("id") @Min(1) Long id) {
        Book book = bookRepository.find(id);

        if(book == null) {
            return Response.status(Response.Status.NOT_FOUND).build();
        }

        return Response.ok(book).build();
    }

    // api/books/count
    @GET
    @Path("/count")
    public Response countBooks() {
        Long nbOfBooks =  bookRepository.countAll();

        if(nbOfBooks == 0) {
            return Response.noContent().build();
        }

        return Response.ok(nbOfBooks).build();
    }

    @DELETE
    @Path("/{id : \\d+}")
    public Response deleteBook(Long id) {
        bookRepository.delete(id);
        return Response.noContent().build();
    }
}

2. Creating a test for the REST endpoint:

package com.pluralsight.bookstore.rest;

import com.pluralsight.bookstore.model.Book;
import com.pluralsight.bookstore.model.Language;
import com.pluralsight.bookstore.repository.BookRepository;
import org.jboss.arquillian.container.test.api.Deployment;
import org.jboss.arquillian.junit.Arquillian;
import org.jboss.arquillian.test.api.ArquillianResource;
import org.jboss.shrinkwrap.api.ShrinkWrap;
import org.jboss.shrinkwrap.api.asset.EmptyAsset;
import org.jboss.shrinkwrap.api.spec.JavaArchive;
import org.junit.After;
import org.junit.Test;
import org.junit.runner.RunWith;

import javax.ws.rs.client.Entity;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.Response;

import java.util.Date;

import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
import static javax.ws.rs.core.Response.Status.CREATED;
import static javax.ws.rs.core.Response.Status.NO_CONTENT;
import static org.junit.Assert.*;

@RunWith(Arquillian.class)
public class BookEndpointTest {
    //testable tell wildfly not to package this test,
    // cause we want to test from outside by using HTTP
    @Deployment(testable = false)
    public static JavaArchive createDeployment() {
        return ShrinkWrap.create(JavaArchive.class)
                .addClass(BookRepository.class)
                .addClass(Book.class)
                .addClass(Language.class)
                .addClass(BookEndpoint.class)
                .addClass(JAXRSConfiguration.class)
                .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml")
                .addAsManifestResource("META-INF/test-persistence.xml", "persistence.xml");
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void createBook(@ArquillianResource("api/books")WebTarget webTarget) {
        // Test counting books
        Response response = webTarget.path("count").request().get();
        assertEquals(NO_CONTENT.getStatusCode(), response.getStatus());

        // Test find all
        response = webTarget.request(APPLICATION_JSON).get();
        assertEquals(NO_CONTENT.getStatusCode(), response.getStatus());

        // Create a book
        Book book = new Book("isbn", null, 12F, 123, Language.ENGLISH, new Date(), "imageURL", "description");
        response = webTarget.request(APPLICATION_JSON).post(Entity.entity(book, APPLICATION_JSON));
        assertEquals(CREATED.getStatusCode(), response.getStatus());

    }
}

[JavaEE] Implement a test for REST endpoint