Unit Testing ASP.NET Web API

If you are looking for guidance on how to Unit Test ASP.NET Web API Controllers, you can find some excellent guidance here:
http://www.asp.net/web-api/overview/testing-and-debugging/unit-testing-with-aspnet-web-api

This example also includes using Moq as your Mocking framework to mock out functionality in your Web API Controllers:
http://www.asp.net/web-api/overview/testing-and-debugging/unit-testing-controllers-in-web-api

This is also another good article on Unit Testing Web API Controllers: http://blogs.msmvps.com/theproblemsolver/2013/11/13/unit-testing-a-asp-net-webapi-2-controller/