SqlInMemory is a library for creating SqlServer database on Memory instead of hard disk, at last Drops and Disposes database when you're done with it.

 This is useful for Integration Testing. 

ASP.NET Core applications can be tested with different testing frameworks and Entity Framework Core makes testing specially easy by removing different technical problems from our way by using in-memory data provider. This blog posts shows how to unit test controllers that use data from Entity Framework Core.