They're not very important if you're the only developer on your team.
If you're working with others, though, then it becomes very important. I don't think I'm being entirely hyperbolic when I say that inconsistent or poorly-chosen formatting rules are the death of 1,000 cuts for a team's productivity.
There's a tiny but existent cost that's incurred every time formatting rules that aren't diff-stable result in a noisy code review that takes longer to read, or makes it harder for reviewers to discern the real changes from the formatting junk. There's a tiny but existent cost when excess delta makes it harder to gitblame. There's a tiny but existent cost when people have to stop and think about how to format their code manually. Or when they have to stop and debate formatting. Or when they read someone else's code slightly more slowly because different formatting rules make it harder for them to skim it or rely on pattern recognition instead of careful reading to understand its structure.
All those tiny little costs add up to something that's not so tiny. And it's so easy to make it just disappear, for the low low cost of swallowing one's pride, by simply adopting an opinionated autoformatter.
> There's a tiny but existent cost that's incurred every time formatting rules that aren't diff-stable result in a noisy code review that takes longer to read, or makes it harder for reviewers to discern the real changes from the formatting junk. There's a tiny but existent cost when excess delta makes it harder to gitblame.
Don't reformat code you didn't otherwise touch. That's just common sense. Common sense autoformatters lack.
> There's a tiny but existent cost when people have to stop and think about how to format their code manually.
I rarely think about how I format my code. When I do, it's because the code is hard to format in a readable way, in which case an autoformatter will produce garbage.
> Or when they have to stop and debate formatting.
"Doctor, it hurts when I do this."
> Or when they read someone else's code slightly more slowly because different formatting rules make it harder for them to skim it or rely on pattern recognition instead of careful reading to understand its structure.
Neglible. To the contrary, different formatting reminds you that you did not write this code and you should read it more carefully because you can't expect its creator to think the way you do.
If you're working with others, though, then it becomes very important. I don't think I'm being entirely hyperbolic when I say that inconsistent or poorly-chosen formatting rules are the death of 1,000 cuts for a team's productivity.
There's a tiny but existent cost that's incurred every time formatting rules that aren't diff-stable result in a noisy code review that takes longer to read, or makes it harder for reviewers to discern the real changes from the formatting junk. There's a tiny but existent cost when excess delta makes it harder to gitblame. There's a tiny but existent cost when people have to stop and think about how to format their code manually. Or when they have to stop and debate formatting. Or when they read someone else's code slightly more slowly because different formatting rules make it harder for them to skim it or rely on pattern recognition instead of careful reading to understand its structure.
All those tiny little costs add up to something that's not so tiny. And it's so easy to make it just disappear, for the low low cost of swallowing one's pride, by simply adopting an opinionated autoformatter.