#!/bin/sh

# A hook script to verify what is about to be pushed.  Called by "git push"
# after it has checked the remote status, but before anything has been pushed.
# If this script exits with a non-zero status nothing will be pushed.
#
# This hook is called with the following parameters:
#
# $1 -- Name of the remote to which the push is being done
# $2 -- URL to which the push is being done
#
# If pushing without using a named remote those arguments will be equal.
#
# Information about the commits which are being pushed is supplied as lines to
# the standard input in the form:
#
#   <local ref> <local oid> <remote ref> <remote oid>
#
# To enable this hook, save or link this file at `.git/hooks/pre-push`.
#
# This prevents pushing of commits where the log message starts with "WIP" (work
# in progress) or "{fixup,squash}!" (Autosquash, see git-rebase(1)).

remote="$1"
url="$2"

zero=$(git hash-object --stdin </dev/null | tr '[0-9a-f]' '0')

while read local_ref local_oid remote_ref remote_oid
do
	if test "$local_oid" = "$zero"
	then
		# Handle delete
		:
	else
		if test "$remote_oid" = "$zero"
		then
			# New branch, examine all commits
			range="$local_oid"
		else
			# Update to existing branch, examine new commits
			range="$remote_oid..$local_oid"
		fi

		# Check for WIP or auto{squash,fixup} commit
		pattern='^(WIP|(fixup|squash)!)'

		commits="$(git rev-list -E --oneline --grep "$pattern" "$range")"
		if test -n "$commits"
		then
			printf >&2 "$local_ref: Commits in progress:\n%s" "$commits"
			printf >&2 "Aborting push"
			exit 1
		fi
	fi
done

exit 0