Coping with refactoring

It is the inevitable nature of code to be refactored. How do we make it a less painful process?

A not-horrible approach to creating a piece of software by first developing the happy path, and then adding extra code to handle other cases. When we do this, we may find that patterns emerge and some parts may be abstracted out to make the code cleaner to read. This makes sense.

It seems that many engineers decided that this process of abstracting is too painful and started using other people’s abstractions pre-emptively in order to avoid having to make a lot of code changes. They may introduce patterns like the ones described in the GoF Design Patterns book.

Some abstractions may be simple to understand. But more often, they almost always make the code longer and more complex. And sometimes, as a part of this crystal ball future-proofing of the code, you may make a mistake 😱. At some point, you will have to change a lot more code than you would’ve had to if you didn’t start trying to make a complex design to begin with. It’s the exact same concept as the adage about premature optimization.

As an example, as a part of one of my previous jobs, I was reviewing code that created 10+ classes that included strategy patterns and interfaces. The code was meant to be generic over something that could be 1 of 4 possibilities. But the 4 possibilities would basically never change. The entire setup could’ve been replaced with a single file with a 4-part if/else statement.

I’m not saying that design patterns aren’t useful. If we had more possibilities, or needed to make it so that programmers outside our team had to be able to introduce their own options, then we would have to rethink the design. But changing an if statement in a single file is trivial. Changing 10+ files and all the places that might’ve accidentally referenced them is not.

Some people think they can dodge the need to refactor by just piling more abstractions on top, in a philosophy known as “Open to extension, closed to modification.” I think this is just a different, more expensive form of refactoring. Increasing the number of objects just increases the amount of code you need to change in the future should requirements or assumptions change.

So the next time you’re thinking of introducing design patterns and creating a boat load of files to hide your potential complexity into, consider whether the cost of adding that abstraction is worth the pain it will take to change it later.

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