Accessing real resources like databases for testing makes the test code hard to write.
And lots of times it also makes running the tests slow.
So instead of setting up a real database for testing, we set up an in-memory database.
We separated application services from i O technologies such as MVC, Web API, WPF, Windows, etcetera
just to improve the software's maintainability.
Awesome.
Well, and that's it.
Congratulations.
Now you can use in-memory databases to test the application services of your software and use the TDD
approach in a real world scenario.