GitHub Actions: Check for `Co-authored-by` format

[koppor]

Project description

The goal is to develop a bot that automatically checks commit messages in a repository for incorrectly formatted Co-authored-by: entries. The Co-authored-by: trailer is a standard used by GitHub and other version control systems to credit multiple contributors to a single commit clearly. Proper formatting typically includes the author's full name and email address. This bot will identify common formatting errors such as missing email addresses, incorrect casing, usage of GitHub usernames instead of proper names, and potentially problematic single-word names. When detecting such issues, the bot should flag or comment on the commit or pull request, guiding contributors to correct their commit message formatting.

Examples of incorrect formats:

Co-authored-by: Julien Example
Co-authored-by: Lucas Tiger
Co-authored-by: Venceslas Mouse

(No email addresses provided)

Co-Authored-By: username <username@users.noreply.github.com>

(GitHub username used instead of real name)

Co-authored-by: @login

(GitHub username instead of proper name and missing email)

Co-authored-by: Christoph <christoph@examle.com>

(Single-word name, potentially ambiguous)

Relevant Technology

• GitHub Actions (recommended for integration and automation)
• Shell scripting, JavaScript, or Python (for parsing commit messages)
• GitHub API for commenting or flagging commits and pull requests

Complexity and required time

Complexity

• Beginner - This project requires no or little prior knowledge of the technolog(y|ies) specified to contribute to the project
• Intermediate - The user should have some prior knowledge of the technolog(y|ies) to the point where they know how to use it, but not necessarily all the nooks and crannies of the technology
• Advanced - The project requires the user to have a good understanding of all components of the project to contribute

Required time (ETA)

• Little work - A couple of days
• Medium work - A week or two
• Much work - The project will take more than a couple of weeks and serious planning is required

Categories

• Mobile app
• IoT
• Web app
• Frontend/UI
• AI/ML
• APIs/Backend
• Voice Assistant
• Developer Tooling
• Extension/Plugin/Add-On
• Design/UX
• AR/VR
• Bots
• Security
• Blockchain
• Futuristic Tech/Something Unique

[jyosnaphilip]

Hi, I'd like to take up this issue.
I've worked with this GitHub API before.

[koppor]

@jyosnaphilip Great! I am looking forward to try it out!

[jyosnaphilip]

If anyone has/know of any repos with co authored commits please comment the links to those repos. I need some examples to test this on.
Or, if anyone knows any other easier ways for me to test, feel free to let me know

[koppor]

https://github.com/jabref/jabref/

---

Related work:

• ghprcomment interpreting Co-authored-by

[koppor]

Other work using the format:

• https://github.com/rkotze/git-mob - Add co-authors to commits when you collaborate on code.
• https://github.com/brettbuddin/partner - partner is a tool for managing coauthors for git commits
• https://github.com/jamesjoshuahill/git-co-author - Easily use 'Co-authored-by' trailers in the commit template.
• https://github.com/spinningarrow/git-coauthors - Lists all authors of a git repo as potential co-authors of a commit.

The last one has a nice terminal-based UI to create co-authored commites. The screenshot also shows Co-authored strings. "partner" also has an example shown.

[hstsethi]

Excellent idea! I would love to contribute to as well.

https://github.com/hstsethi/awesome-symbian

I have manually added co-authors here. Both from Github commit window, and through git amends. One example being commit e341b9e.

Though they are not showing up for some reason. You might want to test on these cases.

[simoncraf]

I've been working on a project that does exactly this: coauthorcheck. It validates Co-authored-by trailers in commit messages, can run locally as a pre-commit hook, in GitHub Actions for branch/PR checks, or directly from the CLI against files, commits, or commit ranges. It also reports actionable errors and suggested fixes. I'd be happy to get any feedback if you try it.