In a previous post I showed how to unit test an ASP.NET WebAPI Controller. But with a REST service there is both a client and a service component. Assuming for a moment the client part is also written in C# we should test that as well. In this case the client application contains the following class to load books from the REST WebAPI controller: 1: public class BooksClient 2: { 3: private readonly HttpClient _httpClient; 4:   5: public BooksClient(HttpClient httpClient) 6: { 7: _httpClient ...