#! /bin/sh
#
# This script ensures Crystal code is correctly formatted before committing it.
# It won't apply any format changes automatically.
#
# Only staged files (the ones to be committed) are being processed, but each file is checked
# entirely as it is stored on disc, even parts that are not staged.
#
# To use this script, it needs to be installed in the local git repository. For example by running
# `ln -s scripts/git/pre-commit .git/hooks` in the root folder.
#
# Called by "git commit" with no arguments. The hook should
# exit with non-zero status after issuing an appropriate message if
# it wants to stop the commit.

changed_cr_files=$(git diff --cached --name-only --diff-filter=ACM | grep '\.cr$')

[ -z "$changed_cr_files" ] && exit 0

if [ -x bin/crystal ]; then
  # use bin/crystal wrapper when available to run local compiler build
  exec bin/crystal tool format --check $changed_cr_files >&2
else
  exec crystal tool format --check $changed_cr_files >&2
fi