Recommend setting up check_line_lengths as a pre-commit script

[jyn514]

I've run into lots of annoying failures from this.

• Make it runnable without arguments
• Add it in the README

Open questions: How does this work on Windows (if at all)?

[LeSeulArtichaut]

Maybe we could also suggest setting up the editor to do the formatting?

[jyn514]

Maybe we could also suggest setting up the editor to do the formatting?

I'm not sure how to do that - in vim I use gqq but I don't know if VSCode or other editors have an equivalent.

[jyn514]

ping @spastorino - can we get this merged? I find it really useful and I'm sure others would too.

[LeSeulArtichaut]

@jyn514 did you solve the "does this work on Windows" question?

[jyn514]

It looks like the fix is cd .git/hooks && New-Item -Path ../../.git_hooks/* -ItemType SymbolicLink -Value . && cd ../.., I'll add that to the docs.

[jyn514]

Updated!

[JohnTitor]

Looks great now, thanks!

[spastorino]

@jyn514 👍, does the script check files when the ignore directive is used?.

[jyn514]

It works the same way as it did before. I don't see any logic for ignoring lines, that seems like a useful follow-up though.

[spastorino]

Just in case, I was referring to // ignore-tidy-linelength which we use mainly in tests like in https://github.com/rust-lang/rust/blob/master/src/test/ui/stability-attribute/generics-default-stability.rs#L1.
I was guessing (didn't read the code) that this pre-commit hook would check that the to be committed files do not have more than 100 length lines but for this to be correct we would need to ignore the ones that use that directive.

[jyn514]

@spastorino hmm, I'm not sure this makes sense to add. // ignore-tidy-linelength is not a comment in markdown, it will show up in the user-facing docs, and I don't think any of the existing markdown files use it.

[spastorino]

I should've read what this was about 😂, I thought it was a script to check Rust source files length before commit, that's why I was thinking about ignoring those. Anyway, nevermind.