如何使用实体框架核心和单元测试进行UnitOfWork +存储库模式

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
}

public class AppDbContext : DbContext
{
    public DbSet<Product> Products { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("YourConnectionStringHere");
    }
}

public interface IProductRepository
{
    IEnumerable<Product> GetAll();
    Product GetById(int id);
    void Add(Product product);
    void Update(Product product);
    void Delete(int id);
}

public class ProductRepository : IProductRepository
{
    private readonly AppDbContext _context;

    public ProductRepository(AppDbContext context)
    {
        _context = context;
    }

    public IEnumerable<Product> GetAll()
    {
        return _context.Products.ToList();
    }

    public Product GetById(int id)
    {
        return _context.Products.Find(id);
    }

    public void Add(Product product)
    {
        _context.Products.Add(product);
    }

    public void Update(Product product)
    {
        _context.Products.Update(product);
    }

    public void Delete(int id)
    {
        var product = _context.Products.Find(id);
        if (product != null)
        {
            _context.Products.Remove(product);
        }
    }
}

public interface IUnitOfWork
{
    IProductRepository ProductRepository { get; }
    void Save();
}

public class UnitOfWork : IUnitOfWork
{
    private readonly AppDbContext _context;
    private IProductRepository _productRepository;

    public UnitOfWork(AppDbContext context)
    {
        _context = context;
    }

    public IProductRepository ProductRepository
    {
        get
        {
            if (_productRepository == null)
            {
                _productRepository = new ProductRepository(_context);
            }
            return _productRepository;
        }
    }

    public void Save()
    {
        _context.SaveChanges();
    }
}

[TestClass]
public class UnitOfWorkTests
{
    private AppDbContext _context;
    private IUnitOfWork _unitOfWork;

    [TestInitialize]
    public void Initialize()
    {
        var options = new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase(databaseName: "TestDb")
            .Options;

        _context = new AppDbContext(options);
        _unitOfWork = new UnitOfWork(_context);
    }

    [TestMethod]
    public void AddProduct_ShouldAddProductToDatabase()
    {
        // Arrange
        var product = new Product { Name = "Test Product", Price = 100 };

        // Act
        _unitOfWork.ProductRepository.Add(product);
        _unitOfWork.Save();

        // Assert
        var addedProduct = _unitOfWork.ProductRepository.GetById(product.Id);
        Assert.IsNotNull(addedProduct);
        Assert.AreEqual("Test Product", addedProduct.Name);
        Assert.AreEqual(100, addedProduct.Price);
    }
}

public void Save()
{
    using (var transaction = _context.Database.BeginTransaction())
    {
        try
        {
            _context.SaveChanges();
            transaction.Commit();
        }
        catch (Exception)
        {
            transaction.Rollback();
            throw;
        }
    }
}

[TestCleanup]
public void Cleanup()
{
    _context.Database.EnsureDeleted();
}