如何对方法进行单元测试以检查其是否保存到数据库？

Question

I need to unit test to check if the Create method saves to the database. I know that this method should not be unit tested in a real project. I am doing this just for learning and demonstration purposes in a school project. I know that I have to use mocking objects and some abstract dependencies of the controller as I read in some other answers, but because I just started learning c# this doesn't help me too much. Can you please show me a simple solution or some advice. Thanks.

This is the Create method:

[HttpPost]
[ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include = "Id,Code,Description")] LocationCode locationCode)
    {
        if (ModelState.IsValid)
        {
            uow.LocationCodeRepository.Insert(locationCode);

            return RedirectToAction("Index");
        }

        return View(locationCode);
    }

This is the LocationCode class from the Model:

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace BookInventory.Models
{
    public class LocationCode
    {
        [Key]
        public int Id { get; set; }

        public string Code { get; set; }
        public string Description { get; set; }

        public virtual ICollection<Book> Books { get; set; }
    }
}

Answer 1

What I did was to create a little class that creates LocalDB test database for every unit test. It is being initialized in the TestInitialize (which runs before every unit test), and it does the following:

1. Check if there is an existing database. If yes, delete it.
2. Create a new database.
3. Seed it with some test data.
4. Run the unit test.
5. Go to the next test, and go back to 1.

This runs very fast and allows you to really test you queries/ORM as well, instead of just mocking the repository and assuming that everything works (which is very wrong in my opinion, especially if you're writing your own queries instead of using LINQ. Refactoring something may break things very easily with SQL queries).