Amend commit support

[domenkozar]

There are some checks that are automatic. We're using brittany (Haskell source formatter) and my workflow goes always as following:

1. make changes
2. commit
3. pre-commit failed
4. amend commit
5. commit again

I was wondering if 3 and 4 could be merged into pre-commit showing the diff and then asking to amend it?

[asottile]

It could, however pre-commit currently doesn't do either of the two things:

• modify the staging area
• have interactivity

The second is difficult as well because git hooks are not handed a tty and would have to (unreliably) fish one out of /dev/tty (not even sure this is possible on windows)

I use:

git add -u && !!

quite often fwiw

[domenkozar]

I guess interactivity was a stretch goal, I would be happy with just "accept the output" as there's nothing one can really do against autoformatter.

I presume modifying the staging area is doable?

[asottile]

one could SKIP / etc. to bypass the auto formatter.

pre-commit takes a strong stance on not modifying the staging area -- here's more reading on that subject: #747 #806 #879

[domenkozar]

Alright :)

[asottile]

thanks for the issue though! 🎉