public void TestCustomer_UI() { //REF: https://msdn.microsoft.com/en-us/library/ms182532.aspx ICustomerGui screen = new CustomersForm(); CustomerPresenter presenter = new CustomerPresenter(screen); screen.CustomerId = "new"; screen.CustomerName = ""; //Please see the ValidateData() method of CustomerPresenter for error messages try { presenter.btnSave_Click(); } catch (ArgumentOutOfRangeException e) { StringAssert.Contains(e.Message, "Name cannot be blank"); return; } Assert.Fail("No exception was thrown."); }