cockroach pre-push hook to run `make check`

pre-push

#!/usr/bin/env bash

[[ "$(git config --bool hooks.checkBeforePush)" = true ]] || exit 0

# Redirect output to stderr.
exec >&2

z40=0000000000000000000000000000000000000000
checked_trees="$(git rev-parse --git-dir)/checked_trees" || {
  echo "unable to determine git directory; aborting push"
  exit 1
}

original_ref="$(git symbolic-ref --quiet --short HEAD)" || original_ref="$(git rev-parse HEAD)" || {
  echo "unable to determine current ref; aborting push"
  exit 1
}

old_stash="$(git rev-parse --quiet --verify refs/stash)" || {
  echo "unable to retrieve current stash sha; aborting push"
  exit 1
}
git stash save --include-untracked --quiet "pre-push temporary stash" || {
  echo "unable to stash current changes; aborting push"
  exit 1
}
new_stash=$(git rev-parse --quiet --verify refs/stash) || {
  echo "unable to retrieve stashed sha; aborting push"
  exit 1
}

cleanup() {
  git checkout --quiet "$original_ref" || {
    echo "unable to return to original ref; aborting push"
    exit 1
  }
  [[ "$old_stash" == "$new_stash" ]] || git stash pop --index --quiet > /dev/null || {
    echo "unable to pop original changes; aborting push"
    exit 1
  }
}
trap cleanup INT EXIT

while read local_ref local_sha remote_ref remote_sha
do
  [[ "$local_sha" = $z40 ]] && exit 0
  tree="$(git rev-parse "$local_sha^{tree}")" || {
    echo "unable to determine tree for pushed ref $local_ref ($local_sha); aborting push"
    exit 1
  }
  grep --quiet -F "$tree" "$checked_trees" && exit 0
  git checkout --quiet "$local_ref" || {
    echo "unable to checkout $local_ref ($local_sha); aborting push"
    exit 1
  }
  make check || {
    echo "make check failed; aborting push"
    exit 1
  }
  echo "$tree" >> "$checked_trees"
done