单元测试一种通过选择C＃进行发布和删除的方法

Question

I have this method which selects one row of a table and copies it to the another table and then it just deletes it from the first one. The problem is that how can I unit test it because it executes two methods (Post and Delete) at the same time.

Here is the method:

public ActionResult Pay(int id, Car car)
    {
        try
        {
            using (BookCarDBEntities db = new BookCarDBEntities())
            {

                var carToDelete = db.Cars.FirstOrDefault(c => c.Id == id);
                var book = CreateNewBooking(carToDelete);
                db.Bookings.Add(book);



                db.Cars.Remove(carToDelete);

                db.SaveChanges();


                return RedirectToAction("ListBookings", "Home");
            }

        }
        catch (Exception ex)
        {
            return View(ex + "error");
        }
    }

    private Booking CreateNewBooking(Car car)
    {
        var bookingCreated = new Booking
        {
            id = car.Id,
            model = car.model,
            make = car.make,
            price = car.price,
            location = car.location
        };

        return bookingCreated;
    }

Answer 1

It does not matter how many external function calls your method to have. To get the values from the method calls in your method (that you wanna unit test), you should mock those methods to return certain responses when called with certain parameters.

You should check Moq to learn how to mock methods. Also, I suggest you wrap your methods with an interface (BookCarDBEntities). It is more important to write code to testable rather than writing tests to unmanageable code. Hope this helps.