RefactoringCringely

refactoring

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A recent piece by Robert Cringely caused a small stir in the refactoring community recently, as he criticized refactoring. Phlip summed the response on the refactoring mailing list with an unusually restrained '...he sounds like a "skeptic" who writes reviews of books he has no intention of reading.'

Certainly it isn't clear how much Cringely understands about refactoring, although he certainly understands the key point about it being a behavior preserving transformation process. What he does do is highlight a number of ways where refactoring is used inappropriately.

One misuse is that of refactoring code that won't change.The whole point of refactoring is that it improves the design of existing code. The value of well designed code is that it is easier to change. Hence you refactor code that you expect to change in the future. There's no point refactoring code that's stable.

Another is his example of a refactoring team that goes into the code of other teams and refactors it. This is the kind of 'service' that I would pay to avoid. Programmers should refactor their own code only, not go banging around in other stuff. XP teams use collective code ownership, which encourages anyone to refactor any code in the team's code base, but this applies only to that team's code. The idea of one team wandering around refactoring other teams' code without telling anyone is certainly not something that I would recommend.

Finally he complains about refactoring being used to cover any form of code changes. As with the others, I agree with him 100%. It's long been one of my pet peeves that people use refactoring as a synonym for restructuring something. Refactoring is a very particular process that uses a series of small semantics-preserving transformations to change a code base. It's quite a particular and disciplined process. There are other ways to restructure code, beneficial or not these are not refactoring.

So on the whole it sounds like I agree with a lot of what Cringely says. That's true, and it's true of the comments on the mailing list. On the whole the annoyance was about a feeling that Cringely mischaracterised refactoring in an eagerness to point the finger at fads.

Where I certainly do part company with Cringely is his opinion that 80% of refactoring is a waste of time and software managers should put a stop to refactoring to save money. The point of refactoring is that improving the design makes it easier to change things, therefore refactoring increases productivity. Certainly programmers need to judge whether the refactoring effort will pay off, and that's not something you can easily quantify. But time after time I've seen people waste time working their way around poorly designed code with patches that only make it worse. Refactoring is a way to get out of that particular death spiral - which is why I consider it to be such a valuable technique.