mock1.java

public class BlogServiceTest {

    @Test
    public void addPost() {
        // given
        AuthClient authClient = ...
        BlogRepository blogRepository = ...

        BlogService service = new BlogService(authClient, blogRepository); // 생성자로 협력 객체 주입
        AddPostRequest request = ...

        // when
        service.addPost(request);

        // then
        ...
    }
}

public class BlogService {

    public BlogService(AuthClient authClient, BlogRepository blogRepository) {
        this.authClient = authClient;
        this.blogRepository = blogRepository;
    }

    public AddPostResponse addPost(AddPostRequest request) {
        long userId = authClient.verifyToken(request.getToken());
        
        Post post = request.getPost();
        long postId = blogRepository.save(userId, post);
        return new AddPostResponse(userId, post);
    }

    public GetPostResponse getPosts(GetPostRequest request) {
        long userId = authClient.verifyToken(request.getToken());

        return new GetPostResponse(blogRepository.findByUserId(userId));
    }
}