public void AttachNewEntityToContext_WhenCalled() { // Arrange var contextOptions = new DbContextOptionsBuilder <AlphaCinemaContext>() .UseInMemoryDatabase(databaseName: "MarkEntityAsModified_WhenCalled") .Options; var testMovie = new Movie { Name = "TestMovie" }; //Act using (var context = new AlphaCinemaContext(contextOptions)) { var movieRepo = new Repository <Movie>(context); movieRepo.Update(testMovie); //Assert Assert.IsTrue(context.Set <Movie>().Local.Any(e => e == testMovie)); } }