public void RemoveMovieFromCartShouldRemoveAMovieFromTheCart() { DbContextOptions <UltimateMoviesDbContext> options = new DbContextOptionsBuilder <UltimateMoviesDbContext>() .UseInMemoryDatabase(databaseName: "Carts_RemoveMovieFromCart_Database") .Options; UltimateMoviesDbContext db = new UltimateMoviesDbContext(options); ICartsService cartsService = new CartsService(db); db.Users.Add(new UMUser { UserName = "******" }); db.SaveChanges(); db.Movies.Add(new Movie { Name = "Test Movie" }); db.Movies.Add(new Movie { Name = "Test Movie 2" }); db.SaveChanges(); db.CartMovies.Add(new CartMovie { UserId = db.Users.Last().Id, MovieId = db.Movies.ToList()[0].Id, Quantity = 1 }); db.CartMovies.Add(new CartMovie { UserId = db.Users.Last().Id, MovieId = db.Movies.ToList()[1].Id, Quantity = 1 }); db.SaveChanges(); cartsService.RemoveMovieFromCart("Test", db.Movies.FirstOrDefault(m => m.Name == "Test Movie 2").Id); int cartMoviesCount = db.CartMovies.ToList().FindAll(c => c.UserId == db.Users.Last().Id).Count(); Assert.Equal(1, cartMoviesCount); }