public void DeleteCourseByUId() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(Guid.NewGuid().ToString()); var repository = new EfDeletableEntityRepository <Course>(new ApplicationDbContext(options.Options)); var userRepository = new EfDeletableEntityRepository <ApplicationUser>(new ApplicationDbContext(options.Options)); repository.AddAsync(new Course() { Title = "test", ApplicationUserId = "asd" }).GetAwaiter().GetResult(); repository.SaveChangesAsync().GetAwaiter().GetResult(); var coursesService = new CoursesService(repository, userRepository); AutoMapperConfig.RegisterMappings(typeof(MyTest).Assembly); var course = coursesService.DeleteAsync(1); Assert.Empty(repository.All()); }