prepare-commit-msg hook for jira id prefixed commit message

prepare-commit-msg

#!/usr/bin/env python

from __future__ import print_function

import re
import sys

GIT_HEAD_REF = '.git/HEAD'
ticket_number = re.compile(r'\b[A-Z]{2,}-[0-9]+')
branch_ticket_number = re.compile(r'\b[a-z]{2,}-[0-9]+')

def get_commit_msg(ref_path):
    with open(ref_path) as commit_msg_object:
        return commit_msg_object.read()

def get_branch_name():
    with open(GIT_HEAD_REF) as git_object:
        ref = git_object.read()
        branch_name = ref.rsplit('/')[-1]
        return branch_name

def get_ticket_number(branch_name):
    matched = branch_ticket_number.match(branch_name)
    return matched.group().upper()

def add_ticket_number(ref_path, ticket_number):
    msg = get_commit_msg(ref_path)
    msg = ticket_number + ' ' + msg
    with open(ref_path, 'w') as commit_msg_object:
         commit_msg_object.write(msg)

def bye(msg):
    sys.stderr.write(msg + '\n')
    sys.stderr.write('PREPARE COMMIT ABORTED' + '\n')
    sys.exit(1)

def next_hook(msg):
    sys.stdout.write(msg + '\n')
    sys.exit(0)

def is_special_branch(branch_name):
    protected_branch_names = ('master', 'develop', )  # NOTE: Change Required
    if branch_name.strip() in protected_branch_names:
        return True
    elif 'integration' in branch_name:
        return True
    return False

def is_commit_contains_ticket_number(commit_msg):
    matched = ticket_number.match(commit_msg)
    return matched and not matched.group().startswith('PEP-8')

def is_empty_msg(msg):
    return not ticket_number.sub('', msg).strip()

def main(_, commit_msg_ref, *args):
    msg = get_commit_msg(commit_msg_ref)
    branch_name = get_branch_name()
    if is_special_branch(branch_name):
        next_hook('Current branch is not a feature branch. Skipped')
    elif is_empty_msg(msg):
        bye('Commit message should have message body')
    elif is_commit_contains_ticket_number(msg):
        next_hook("Commit message already contains a Jira ticket number. Skipped")
    else:
        ticket_number = get_ticket_number(branch_name)
        add_ticket_number(commit_msg_ref, ticket_number)
        pass

if __name__ == '__main__':
    main(*sys.argv)