Sunday, February 25, 2007

Bad Code

Soon after writing my Good Code post I ran into some code that really sucked. It was hard to understand and hard to modify. The sad part was that it met most of my "good code" criteria - it had reasonable names, little duplication, and small methods. You could criticize some of the coupling, but that wasn't the cause of its "ugliness". (In the process of refactoring it I found several bugs, which demonstrates that "good code" is not just an aesthetic judgment, but really does affect the quality of software products.)

Knowing some of the history of the code, how it had grown, I could see why it ended up like it did. You could blame some of the problems on insufficient refactoring as it was worked on. The programmers working on it had just been concerned with getting their task accomplished. If they noticed how ugly it had become, they probably felt they didn't have time to do anything about it.

The lesson is that the criteria in Good Code are necessary, but not sufficient. You need to do them, but you also need to think about whether the end result is understandable.

No comments: