“ What we hope is becoming clear from this chapter is how we’re growing a design from what looks like an unpromising start. We alternate, more or less, between adding features and reflecting on - and cleaning up - the code that results. The cleaning up stage is essential, since without it we would end up with an unmaintainable mess. We’re prepared to defer refactoring code if we’re not yet clear what to do, confident that we will take the time when we’re ready. In the meantime, we keep our code as clean as possible, moving in small increments and using techniques such as Null Implementation to minimise the time when it’s broken.
Section on “Emergent Design” within current draft of Growing OO Software, Guided by Tests by Steve Freeman & Nat Pryce.
