Git 'pre-receive' hook and 'git-clang-format' script to reliably reject pushes that violate code style conventions

Question

Let\'s immediately start with a scrap of the pre-receive hook that I\'ve already written:

#!/bin/sh
##
  format_bold=\'\\033[1m\'
   format_red=\'\\         


        

Answer 1

Condensed

I had a little bit of trouble understanding the first example, in part due to the length and extra tidbits that make it useful for the OP's specific use case. I combed through and condensed it down to this:

ref_name=$1
new_rev=$3

# only check branches, not tags or bare commits
if [ -z $(echo $ref_name | grep "refs/heads/") ]; then
  exit 0
fi

# don't check empty branches
if [ "$(expr "${new_rev}" : '0*$')" -ne 0 ]; then
  exit 0
fi

# Checkout a copy of the branch (but also changes HEAD)
my_work_tree=$(mktemp -d -t git-work-tree.XXXXXXXX) 2>/dev/null
git --work-tree="${my_work_tree}" --git-dir="." checkout $new_rev -f >/dev/null

# Do the formatter check
echo "Checking code formatting..."
pushd ${my_work_tree} >/dev/null
prettier './**/*.{js,css,html,json,md}' --list-different
my_status=$?
popd >/dev/null

# reset HEAD to master, and cleanup
git --work-tree="${my_work_tree}" --git-dir="." checkout master -f >/dev/null
rm -rf "${my_work_tree}"

# handle error, if any
if [ "0" != "$my_status" ]; then
  echo "Please format the files listed above and re-commit."
  echo "(and don't forget your .prettierrc, if you have one)"
  exit 1
fi

This example is using Prettier, but it'll map pretty well to clang-format, eslint, etc. There are a few limitations to the (perhaps oversimplified, but working) example above. I'd recommend diving deeper...

Better, but longer

Once you've grok'd that I'd also recommend taking a scroll down towards the bottom of this one:

• Reject Ugly Commits with Server-Side Git Hooks