用于单元测试我无法轻松创建的返回类型的选项
我需要对一个方法进行单元测试，该方法返回一个我无法轻易伪造或实例化的类型。该类型实现了 IQueryable 我最初认为我可以利用它来发挥我的优势，但目前我不知道如何使用。
例如：
public sealed class MyTrickyClass<T> : IQueryable<T>
{
...
}
public MyTrickyClass<T> GetData()
{
return repository.GetAllData();
}
和我的单元测试
[Test Method]
public void CanGetData()
{
var data = (new List<Record>() { new Record() }).AsQueryable();
var mockRepository = new Mock<IRepository<Record>>();
mockRepository.Setup(s => s.GetAllData()).Returns(data);
MyService service = new MyService(mockRepository.Object);
var result = service.GetData();
Assert.IsNotNull(result);
}
这不会编译，因为 GetAllData() 的返回类型是 MyTrickyClass。如果我尝试将 data 转换为 MyTrickyClass 类型，则转换会失败。
所有这些都是有道理的，但这让我想知道正确的解决方案是什么。对于这种情况有哪些解决方法？我也许可以更改 MyTrickyClass，但理想情况下我想找到一个不影响它的解决方案。
I need to unit test a method that returns a type I can't easily fake or instantiate. The type implements IQueryable<T> which I originally thought I could use to my advantage, but I don't see how at this point.
For example:
public sealed class MyTrickyClass<T> : IQueryable<T>
{
...
}
public MyTrickyClass<T> GetData()
{
return repository.GetAllData();
}
and my unit test
[Test Method]
public void CanGetData()
{
var data = (new List<Record>() { new Record() }).AsQueryable();
var mockRepository = new Mock<IRepository<Record>>();
mockRepository.Setup(s => s.GetAllData()).Returns(data);
MyService service = new MyService(mockRepository.Object);
var result = service.GetData();
Assert.IsNotNull(result);
}
This won't compile because the return type of GetAllData() is MyTrickyClass<T>. If I try to cast data to a MyTrickyClass<Record> type, the cast fails.
All this makes sense, but it leaves me wondering what the right solution is. What are some workarounds for this kind of situation? I may be able to change the MyTrickyClass, but ideally I'd like to find a solution that leaves it alone.
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MyTrickyClass实现接口ITrickyClass，它继承自IQueryable。这对你的类本身来说似乎是微乎其微的，而且你有一个很好的嘲笑接缝。You could have
MyTrickyClass<T>implement interfaceITrickyClass<T>, which inherits fromIQueryable<T>. That seems minimally invasive to your class itself, and you'd have a good seam for mocking.测试中的
data变量是IQueryable，而不是MyTrickyClass。以下是修复它的一些可能性：
data更改为MyTrickyClass（尽管我猜测这是否可能，您已经完成了它）MyTrickyClass更容易构造，然后执行上述操作IRepository的接口，以便它返回一个IQueryable而不是MyTrickyClass（如果它所需要的只是IQueryable的话，这是最好的）IQueryable创建数据，因为转换将会失败。不过，您可以创建一个ITrickyClass的模拟，或者创建一个实现该接口的小存根类（如果MyTrickyClass是一个域对象，您可能会使用它无论如何，在很多地方，所以手工编码的存根可能更有用）。Your
datavariable in the test is anIQueryable<Record>, not aMyTrickyClass<Record>.Here are some possibilities for fixing it:
datain the test to be aMyTrickyClass<Record>(though I'm guessing if this was possible you'd already have done it)MyTrickyClasseasier to construct, then do the aboveIRepositoryso that it returns anIQueryableinstead of aMyTrickyClass(which is best if all it needs is theIQueryableanyway)MyTrickyClassthen you probably want to be isolating yourself from it anywayIQueryableas the cast will fail. You could create a mock ofITrickyClassinstead, though, or create a little stub class that implements the interface (ifMyTrickyClassis a domain object, you'll probably be using it in a lot of places anyway, so a hand-coded stub may be more useful).