Why use OWIN TestServer?

Question

This article shows how to host an entire web API stack in memory for testing using OWIN:

http://www.davidwhitney.co.uk/Blog/2015/01/07/testing-an-asp-net-webapi-app-in-memory/

Whereas this article shows using the OWIN TestServer to unit test controllers:

https://blog.jcorioland.io/archives/2014/04/01/using-owin-to-test-your-web-api-controllers.html

The difference I see is between the use of TestServer.Create and WebApp.Start<Startup>

What is the key difference and why would you choose one over the other?

Is it simply the difference between unit testing controller methods as web api calls versus end-to-end integration testing in memory?

Rupp

I am trying to design a microservices solution and wondering about the same question... did you find any more information meanwhile? – Loria

No, I didn't, I'm afraid. – Rupp

Answer 1

When you do TestServer.Create<Startup>() - you start just the in-memory instance using your startup file. The HttpClient that is inside TestServer is enough for integration testing in-memory. We are starting all the testservers inside one process, so this is not a limitation (currently 4 test servers are running together).

When you do WebApp.Start<Startup>(Settings.WebApiUrl) - you start a web app on the url you provide. There is also another overload which accepts options: both urls and settings. We are using this option only for specific cases. Such as:

1. Hosting url for SignalR client - it won't work without the URL, where it could run
2. Contract based testing - verification of the contracts on provider side. This also can be done only through started WebApp. (We're using Pact.Net)

Oscillogram

This explanation saves my day. When you say specific cases, is hosting web socket client included? I used TestServer.Create<Startup>() initially and I can get the web socket client connected. After switching to WebApp.Start<Startup>(Settings.WebApiUrl) eveything works like a charm. #63591961 – Bonaire