记忆库模式和单元测试

我已经看到了存储库模式的一些实现，非常简单直观，链接到 stackoverflow 中的其他答案

http://www.codeproject.com/Tips/309753/Repository-Pattern-with-Entity-Framework-4-1-and-C http://www.codeproject.com/Tips/309753/Repository-Pattern-with-Entity-Framework-4-1-and-C http://www.remondo.net/repository-pattern-example-csharp/ http://www.remondo.net/repository-pattern-example-csharp/

public interface IRepository<T>
{
    void Insert(T entity);
    void Delete(T entity);
    IQueryable<T> SearchFor(Expression<Func<T, bool>> predicate);
    IQueryable<T> GetAll();
    T GetById(int id);
}

public class Repository<T> : IRepository<T> where T : class, IEntity
{
    protected Table<T> DataTable;

    public Repository(DataContext dataContext)
    {
        DataTable = dataContext.GetTable<T>();
    }
...

在进行单元测试时如何将其设置为从内存中工作？有没有办法从内存中的任何内容构建 DataContext 或 Linq 表？我的想法是创建一个集合（列表、字典...）并在单元测试时对其进行存根。

Thanks!

编辑： 我需要这样的东西：

• 我有一本班级书
• 我有一个班级图书馆

• In the Library构造函数，我初始化存储库：

  var bookRepository = new Repository<Book>(dataContext)

• And the Library方法使用存储库，如下所示

  public Book GetByID(int bookID)
  { 
      return bookRepository.GetByID(bookID)
  }
  

测试时，我想提供一个内存上下文。在生产中，我将提供真实的数据库上下文。

我建议使用像这样的模拟库Moq https://code.google.com/p/moq/ or 犀牛模型 http://hibernatingrhinos.com/oss/rhino-mocks。可以找到一个使用 Moq 的很好的教程here http://www.codeproject.com/Articles/47603/Mock-a-database-repository-using-Moq.

在决定使用哪一种之前，以下信息可能会有所帮助：

• http://graemef.com/blog/2011/02/10/A-quick-comparison-of-some-.NET-mocking-frameworks/ http://graemef.com/blog/2011/02/10/A-quick-comparison-of-some-.NET-mocking-frameworks/

• http://jimmykeen.net/articles/09-jul-2012/mocking-frameworks-comparison-part-1-introduction http://jimmykeen.net/articles/09-jul-2012/mocking-frameworks-comparison-part-1-introduction

附加信息：单元测试框架对比可以找到.

UPDATE 按照OP的要求

创建内存数据库

var bookInMemoryDatabase = new List<Book>
{
    new Book() {Id = 1, Name = "Book1"},
    new Book() {Id = 2, Name = "Book2"},
    new Book() {Id = 3, Name = "Book3"}
};

模拟您的存储库（我在以下示例中使用了 Moq）

var repository = new Mock<IRepository<Book>>();

设置您的存储库

// When I call GetById method defined in my IRepository contract, the moq will try to find
// matching element in my memory database and return it.

repository.Setup(x => x.GetById(It.IsAny<int>()))
          .Returns((int i) => bookInMemoryDatabase.Single(bo => bo.Id == i));

通过在构造函数参数中传递模拟对象来创建库对象

var library = new Library(repository.Object);

最后进行一些测试：

// First scenario look up for some book that really exists 
var bookThatExists = library.GetByID(3);
Assert.IsNotNull(bookThatExists);
Assert.AreEqual(bookThatExists.Id, 3);
Assert.AreEqual(bookThatExists.Name, "Book3");

// Second scenario look for some book that does not exist 
//(I don't have any book in my memory database with Id = 5 

Assert.That(() => library.GetByID(5),
                   Throws.Exception
                         .TypeOf<InvalidOperationException>());

// Add more test case depending on your business context
.....