git-hook to include the ticket-number in the commit-message for feature- and fix-branches. Requiring the syntax of "feature/187-my-branch".

prepare-commit-msg

#!/usr/bin/env python
import sys
import re
from subprocess import check_output

print("Starting commit message hook...")

supported_branch_types = ["fix", "feature"]
regex = '(?<=\/)[0-9]+'

commit_msg_filepath = sys.argv[1]

branch = check_output(
    ['git', 'symbolic-ref', '--short', 'HEAD']).strip().decode()

branch_type = branch.split('/')[0]

if branch_type in supported_branch_types:
    regex_match = re.search(regex, branch)

    if regex_match is not None:
        ticket_number = regex_match.group(0)
        print("using ticket-number:", ticket_number)
        with open(commit_msg_filepath, 'r+') as file:
            commit_msg = file.read()
            if not commit_msg.startswith('%s - ' % (ticket_number)):
                file.seek(0, 0)
                file.write('%s - %s' % (ticket_number, commit_msg))
    else:
        print("no ticket-number found in branch-name")
        # raise Exception("it is required to include a ticket-number in branch-name")