public async Task CustomerAppointmentHistory_ReturnsAViewResult_WithUserName()
{
var controller = new CustomerController();
var user = "******";
var result = await controller.AppointmentHistory(user);
var viewResult = Assert.IsType <ViewResult>(result);
var model = Assert.IsAssignableFrom <AppointmentViewModel>(viewResult.ViewData.Model);
Assert.Equal(user, model.CustomerUsername);
}