Testing as a learning sandbox

I've been spending some quality time with NHibernate 3.0.  Last night I got stuck on an issue with the Criteria query where a collection passed to a constructor was null and the framework was complaining.  After writing a couple of integration tests that tested various parts of my domain object model, I was able to determine that collection types that I was using for the many-side of relationships (ISet<T> and HashSet<T> in this case) where the inappropriate collection types to be using for my collection semantics configuration.  I'm continually amazed at how powerful testing, both unit and integration, can be.  My tests today allowed me to create a sandbox to try things and work out a misunderstanding that I had with NHibernate.  Pretty cool.

.NET Base Class Library types not friendly to mocking with MoQ

I spent some quality time this week driving a design implemented in .NET using unit tests.  It was an enlightening experience and gave me a good glimpse at the quality of the BCL design.  I'm not impressed. We had issues trying to mock System.Net.WebRequest and System.Net.WebResponse and its decendents.  It seems that Microsoft prefers to expose abstract base classes, instead of using interfaces for this.  The aforementioned types are not interface types; they're abstract classes.  We've been using MoQ, a fine mocking framework, at the client I've been working at and I tried to create mock implementations of the System.Net.WebRequest and System.Net.WebResponse types.  No go--these types do not have public constructors.  The non-virtual, non-abstract methods also give MoQ headaches (good write up here about why methods of these abstract class types have to be explicitly decorated with virtual if you want to mock them).  Personally, I'm more fond of exposing interface types, thus alleviating the problem all together.  Very frustrating.  We did continue to unit test and utilized mocks for this, but it forced us to wrap these BCL types with our own types where we could control the virtual decoration.  Yuck!!