Fix Windows support by handling sh shebangs from pre-commit

[jooh]

As of 2.17, pre-commit prepends a #!/bin/sh to its hooks under Windows. This breaks noxfile.py since activate_virtualenv_in_precommit_hooks only matches on bash in the first line of the script. I added a sh key to headers and that seems to have resolved the issue at my end.

pre-commit/pre-commit#2182

https://github.com/pre-commit/pre-commit/pull/2187/commits

[cjolowicz]

Thanks for catching this!

This function does a simple substring match on the shebang. With a two-letter command like sh, the check needs to become more specific. But not too specific, because shebangs can also contain options.

So how about matching entire words?

Instead of

            if executable in lines[0].lower():

we'd do this:

            if executable in lines[0].lower().split():

Update: Just realized this does not work because the new pre-commit scripts use #!/bin/sh (which is one word). Can you change the key from sh to /bin/sh? And we keep the substring matching as-is.

[jooh]

Just realized this does not work because the new pre-commit scripts use #!/bin/sh (which is one word). Can you change the key from sh to /bin/sh? And we keep the substring matching as-is.

Got it. In principle we could now miss #!/usr/bin/env sh shebangs, but given this code only runs on pre-commit-generated hooks I don't think that scenario is possible.

[cjolowicz]

Thank you!