如何使用Rhino Mocks捕獲Stream屬性的值？

Question

[TestClass] 
public class FooTests { 
     [TestMethod] 
     public void TestFoo() { 
      var fooMock = MockRepository.GenerateMock<IFoo>(); 
      // MUT 
      FooUser.Run(fooMock); 

      var stream = fooMock.Content; 
      stream.Position = 0; 

      var first = stream.ReadByte(); 
      Assert.AreEqual(0x77, (byte) first); 
      var second = stream.ReadByte(); 
      Assert.AreEqual(0x78, (byte) second); 
     } 
    } 

    public class Foo :IFoo { 
     public Stream Content { get; set; } 
    } 

    public class FooUser { 
     public static void Run(IFoo foo) { 
      foo.Content = new MemoryStream(new byte[] {0x77, 0x78}); 
     } 
    } 

    public interface IFoo { 
     Stream Content { get; set; } 
    } 

AssertWasCalled似乎不適合驗證流。

fooMock.Content.Stub(aStream => stream = aStream); 

拋出異常：

System.ArgumentNullException: You cannot mock a null instance 
Parameter name: mock 

注：好像痣會的工作對於這個問題更好。

Answer 1

替換：

var fooMock = MockRepository.GenerateMock<IFoo>(); 

有：

var fooMock = MockRepository.GenerateStub<IFoo>();