public void given_employee_with_long_firstname_and_lastname_when_validating_should_return_error_about_full_name_being_too_long() { var employee = new Employee { FirstName = "ToddMeinershagenToddMeinershagenToddMeinershagen", LastName = "ToddMeinershagenToddMeinershagenToddMeinershagen" }; var results = new List<ValidationResult>(); employee.TryValidate(results) .Should().BeFalse(); results.Should() .Contain(x => x.ErrorMessage == "The full name must not be longer than 100 characters."); }