Coding standards gone wrong


I personally believe in standards insofar they magically get rid of the petty stuff. So here is clang-format for you. Nothing can go wrong, right? Or can it?

Here are some more things to consider when adopting a formatting tool.

We are adopting a standard!

It was hard enough to convince every body that clang-format is better than what we have now (aka nothing). There is no way adopting a configuration from a foreign company will cut it. So we democratically adopt our own configuration. After some deliberation, it is finally done: Every body is happy. We finally have a way to enforce conformance to something and this is a step up, quality-wise.

What can go wrong?

Well something is wrong when clang-format is responsible for the majority of the changes for every pull request.

It is wrong because it makes git blame useless. It is wrong because it is now a policy that whitespace changes and code changes are merged into one commit. Finally it is wrong because it adds noise to the code review and not only does this cost time but mistakes are going to be overlooked.

What went wrong?

Something went wrong in the requirements. It is important to have standards. Per se. And that includes formatting standards because some people do care and format their code properly and some people don't. Adopting a formatting standard is therefore a first measurable step toward quality.

It just is not enough. If code is read more than written, this most obviously holds for code reviews where it must be read. Formatting standards should therefore be required to minimize changes.

So forget about aligning those equal signs and putting as much as possible on a single line. The former will reformat everything when the size of the longest line changes. The latter will reformat the code once the line exceeds the maximum line length.


Go for a big name standard like LLVM or Google. Whatever they do it is good enough for us. Even if some contradict this post. If this is not possible, aim at invariance under refactoring and you will actually do better than the big names.

This is a fictitious story by the way.

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