A git hook for prefixing commit messages with local branch names that are prefixed with Jira issue IDs. To be used as `prepare-commit-msg`

prepare-commit-msg.py

#!/usr/bin/env python3
import sys
import subprocess
import re

jira_pattern = re.compile(r'^\w+-\d+')

result = subprocess.run(['git', 'symbolic-ref', '--short', 'HEAD'], stdout=subprocess.PIPE)
if result.returncode == 0:
    git_output = result.stdout.decode('utf-8')
    discovered_branch_issue = jira_pattern.match(git_output)

if len(sys.argv) > 0:
    with open(sys.argv[1], 'r+') as commit_file:
        commit_msg = commit_file.read()
        discovered_commit_issue = jira_pattern.match(commit_msg)

        new_commit_msg = None

        if discovered_branch_issue:
            if discovered_commit_issue:
                if discovered_branch_issue.group(0) != discovered_commit_issue.group(0):
                    sys.stderr.write("Rewriting commit message...\n")
                    new_commit_msg = jira_pattern.sub(discovered_branch_issue.group(0), commit_msg)
            else:
                new_commit_msg = "%s %s" % (discovered_branch_issue.group(0), commit_msg)

        if new_commit_msg:
            commit_file.seek(0)
            commit_file.write(new_commit_msg)
            commit_file.truncate()

Installation

1. Create a hooks directory

$ mkdir -vp ${HOME}/.config/git/hooks

2. Configure global git config to point to hookspath

$ git config --global core.hookspath ${HOME}/.config/git/hooks

3. Place the above gist in the hooks directory you created above and name it as prepare-commit-msg

4. Make sure the hook is executable

$ chmod u+x ${HOME}/.config/git/hooks/prepare-commit-msg

Usage

1. In your local working copy, create a new branch prefixed with a Jira issue ID.

$ git checkout -b FOO-123/my-feature

2. Try committing a message without the Jira ID

$ git commit -m "Some helpful new widget"

3. Confirm that your commit message was rewritten to FOO-123 Some helpful new widget

$ git log -1