Andy Butland

Without intending to when I started, I've three posts on a topic now, which I think constitutes a series on "Practical Decisions on Testing". Previously posts have covered: Trading off value with difficulty Code coverage metrics As with the above two posts, the intention I've primarily got is to put down in words some discussions I've had at various times, for a reference and as something to point to. In this post I want to discuss what we consider as "the unit" when it comes to unit testing. For many developers, it's the class, and the mark of good coverage is to ensure that all public methods - and via them, the private ones - are covered by tests. In doing so, there will certainly be a well tested code base. There can be a downside discovered in this though, in that it serves as a deterrent for refactoring at the inter-class level. For example, a decision to split the responsibilities of a class into two to better meet the single re