#!/usr/bin/env bash
# To install:
# ln -sf ../../scripts/pre-commit .git/hooks/pre-commit
set -o errexit
set -o nounset
set -o pipefail

readarray staged < <(git diff --name-only --cached)
[[ ${#staged[@]} = 0 ]] && exit
unstash() {
  local ret=$?
  set +e
  git stash pop -q
  exit "$ret"
}
git stash push --quiet --keep-index --message "pre-commit"
trap unstash EXIT

# always ignore untracked files
mapfile -t untracked < <(git ls-files --others --exclude-standard)
if [[ ${#untracked[@]} -gt 0 ]]; then
  for item in "${untracked[@]}"; do
    exclude_args+=("--excludes" "$item")
  done
  treefmt=(treefmt "${exclude_args[@]}")
else
  treefmt=(treefmt)
fi
"${treefmt[@]}"

{
  changed=$(git diff --name-only --exit-code);
  status=$?;
} || true
if [[ $status -ne 0 ]]; then
  exec 1>&2
  echo Files changed by pre-commit hook:
  echo "$changed"
  exit $status
fi