Rhino-Mocking ExpectationViolationException

Question

I started to use Rhino-Mocks and Unit-Tests a few days ago so I'm new in this.

I created a disposable class like this:

public class SomeClass : IDisposable
{
    private bool _disposed;

    public SomeOtherClass ObjB { get; private set; }

    public SomeClass(SomeOtherClass b)
    {
        ObjB = b;
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (_disposed)
            return;

        if (disposing)
        {
            // set all properties to null

            ObjB = null;
            // ...
        }

        _disposed = true;
    }
}

and the unit test which should check if the dispose was done correctly:

[TestFixture]
public class SomeClassTests
{
    [Test]
    public void ShouldDisposeCorrectly()
    {
        var classB = MockRepository.GenerateStrictMock<SomeOtherClass>()
        SomeClass smth;

        using (smth = MockRepository.GenerateStrictMock<SomeClass>(classB))
        { }

        smth.Expect(p => p.ObjB).Should().BeNull();
    }
}

Now when I start the test it throws the following error: Rhino.Mocks.Exceptions.ExpectationViolationException : SomeClass.Dispose(True); Expected #0, Actual #1.

Can you help me to find the missing step? :-)

Answer 1

What are you actually wanting to test here?

That the compiler produces the correct code when you use a using statement? Seems fairly pointeless.

Or that your class implements IDisposable? You could do that with a simpler test.

Or that your disposal routine correctly disposes of the resources? This test doesn't check that. You could completely empty the Dispose(bool) method and the test you say you want to write would still pass.

Better to check that ObjB is null after the object has been disposed and that any other things which should be done in the dispose method have been. What you want to check is that the behaviour when you dispose your object is what you expect