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20040324 Wednesday March 24, 2004

Refactoring: making things better in little increments I had a nice conversation with some folks who weren't looking to for help building The Next Great Thing (that was yesterday's nice conversation). They just had a mish mash of code, all Perl, old and new (but mostly old), that needed to be revamped. They didn't say that they needed a refactorer but that's about what it boils down to: their code needs some serious refactoring.

The funny thing was, the code in question sound like the kind of stuff that you'd typically think of as refactoring candidates. A lot of it is apparently old CGI's (run as Plain Old CGI's or Apache::Registry scripts) that atrophied into speghetti of gobbledy gook. So the problem there isn't one of taking software objects and restructuring them for better design, the first refactoring, if you will, is to take a bunch of procedural code and re-compose it as an object system.

Frankly, this could sound really boring. But on the other hand, there can be something very satisfying in something like this. Have you ever set aside an afternoon or a day to clean out the garage? You sort through a bunch of junk, shelve things that were set down on the floor, throw out a bunch of garbage, fire up the shop-vac and vacuum out all of the cob webs and organize the toolchest. In the end, you haven't produced anything tangible with any value. But you've created something that allows for creating value. I would never go into the garage and build a planter box if it's all cluttered and dusty. It's just too grotty.

Code gets the same way. It gets cluttered and dusty. Refactoring is explicitly not about creating tangible value (i.e. you don't add new features in a refactoring), it's about creating an environment within which tangible value can be created. Fowler sez that refactoring is more than just "cleaning up code" - it's a more methodical, tested and controlled fashion of cleaning up. That's all good. Unfortunately, it seemed as though I drew a blank stare from these folks when I talked about testing. I mean, I understand that test harnesses in Perl such as plain old Test, Test::Unit and Test::Harness are hardly standardized or well entrenched in Perl culture but it was kinda disheartening to see only vague recognition of the value of writing tests. When you're done cleaning the garage, there's that satisfying feeling knowing that you've brought a little order to a chaotic corner of the world. I get that same feeling when I'm working on code, breaking it and fixing it and when it's all said and done, running the test harness; see "100% passed" is another way of bringing order to the chaos.

Anyway, so the basic starting points for refactoring were absent: a system of objects and a test harness but if the goal of refactoring is to "make the software easier to understand and modify" (quoting Fowler, again) then perhaps just getting things to that starting point is the first important refactoring to undertake. Somehow, I don't think the connection between the "fire fighting" mode that these folks were perpetually in and absence of tests was immediately clear to them. They know that "things" need to be fixed (which is a good start) but IMO those fixes need to come in little increments of refactoring.

Now, I've never unit tested a garage cleaning effort but today's conversation made me consider how that'd be done. ( Mar 24 2004, 10:43:06 PM PST ) Permalink


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