public void Update_Post_ReturnsViewIfModelStateIsNotValid() { // Arrange var controller = new CausaleController(new InMemoryCausaleRepository()); controller.ModelState.AddModelError("", "error message"); Causale oCausale = GetCausale(1, ""); // Act var result = controller.Update(oCausale); // Assert Assert.IsInstanceOfType(result, typeof(RedirectToRouteResult)); var vc = new ValidationContext(oCausale, null, null) { MemberName = "Descrizione" }; var validationResults = new List<ValidationResult>(); // Validate the whole Customer entity. bool isValidCausale = Validator.TryValidateObject(oCausale, vc, validationResults, true); Assert.IsFalse(isValidCausale); RedirectToRouteResult routeResult = result as RedirectToRouteResult; Assert.AreEqual(routeResult.RouteValues["action"], "Edit"); }