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by lcnPylGDnU4H9OF 585 days ago
> Only to spend the next year systematically restoring most of those pieces of complexity as whoever was on pager duty that week got to experience a high-pressure object lesson in why some design quirk of the original existed in the first place.

Just to emphasize the point: even if it's not obvious why there is a line of code, it should at least be obvious that the line of code does something. It's important to find out what that something is and remember it for a refactor. At the very least, the knowledge could help you figure out a bug a day or two before you decide to pore over every line in the diff.
1 comments
mandevil 585 days ago
In my refactoring I always refer to that as Chesterton's Fence. Never remove something until you know why it was put in in the first place. Plenty of times it's because you were trying to support Python 3.8 or something else obsolete, and a whole lot of the time it's because you thought that the next project was going to be X so you tried to make that easy but X never got done so you have code to nowhere. Then feel free to refactor it, but a lot of the time it's because of good reasons that are NOT obsolete or overtaken by events, and when refactoring you need to be able to tell the difference.

https://www.chesterton.org/taking-a-fence-down/ has the full cite on the names.

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bunderbunder 585 days ago
Incidentally the person who really convinced me to stop trying to future-proof made a point along those lines. Not in the same language, but he basically pointed out that, in practice, future-proofing is usually just an extremely efficient way to litter your code with Chesterton's Fences.
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suzzer99 585 days ago
I got really 'lucky' in that the first major project I ever worked on was future-proofed to high heaven, and I became the one to maintain that thing for a few years as none of the expected needs for multiple layers of future-proofing abstraction came to pass. Oh but if we ever wanted to switch from Oracle to Sybase, it would have been 30% easier with our database connection factory!

I never let that happen again.

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bunderbunder 585 days ago
IME that kind of thing is more likely to make it 300% harder.

This idea of easy, worry-free database replatforming strikes me as kind of a shibboleth for identifying people who’ve never done it before. In reality they all have subtle differences in semantics and query optimization behavior that mean that every touch point needs close attention to make sure you understand how the behavior in that part of the system changes (assume it will change) and if that change is acceptable. Thinking abstraction layers can eliminate the need for close attention to a DBMS port is the software engineering equivalent of thinking adaptive cruise control means you can play Slay the Spire while driving to the office.

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suzzer99 584 days ago
It was even more ludicrous in this case because a ton of the app logic was inside stored procedures.
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dasil003 585 days ago
> ...if we ever wanted to switch from Oracle to Sybase...

Yeah like Oracle would ever let that happen

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mywittyname 585 days ago
This can be a huge road block. Even if the developer who wrote the code is still around, there's no telling if they will even remember writing that line, or why they did so. But in most projects, that original developer is going to be long gone.

I leave myself notes when I do bug fixes for this exact reason.

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