Allow running `set-version` in GitHub actions

[MarcoIeni]

Motivations

It would be nice to quickly run release-plz set-version without the need to git checkout the PR locally.

Solution

Release-plz checks the PR comments and reacts to comments respecting the regex release-plz set-version <set-version-args>. If one comment is detected, it runs it from gh actions.

Note:

• the commands given in the github comments of the action should be re-applied everytime the PR is updated.
• the output of the command should be the same if run on main or in a branch.

Additional context

• Initially discussed in https://github.com/MarcoIeni/release-plz/issues/704
• kind of related issue https://github.com/MarcoIeni/release-plz/issues/636

[MarcoIeni]

This issue is taken by an external contributor 🎉 They will raise PRs or write in GitHub soon.

[LNSD]

I am working on a GH workflow file for rapid prototyping of this functionality. Once the Proof-of-concept is working, I will integrate this into Rust.

So far, I managed to:

• Add a 'comment command' workflow that executes when a new comment is added to the "new release PR".
• The interaction with the workflow command is restricted by role to the repository admins, admin, and the maintainers, write.
• The command extraction workflow step extracts the set-version arguments and passes them to a release-plz set-version step.
• A 👍🏼 emoji reaction is set to notify the user the command has been detected.
• The version update is applied using the release-please command step.

I got stuck with the last part: committing the changes and updating the release PR. I suspect this last part should be performed using the release-plz release-pr command. Thus, a signed commit is created using the GitHub API and then pushed to the PR, updating the title and description.

Here you can find the POC workflow file (WIP): https://github.com/LNSD/release-plz-fixtures/blob/08ac25c5373708291b2a8519d7de556eab606c26/.github/workflows/release-cmd.yml

[MarcoIeni]

I think for the last part (where you got stuck), it's easier to do it in rust because you could reuse parts of the code of release-pr command. 👍

[MarcoIeni]

Here's some docs on how to commit and push to the release pr: https://release-plz.ieni.dev/docs/github/output#example-commit-files-to-the-release-pr

[LNSD]

For the record. This is a common use case that I am trying to cover with this release PR workflow command:

1. I do my normal development in my project and push an internal logic-breaking change.
2. The release-plz action kicks in and creates the release PR (using the release-pr command). However, as the change is not in the public-facing API, the version gets a minor/patch version bump (e.g., v0.2.1 instead of v0.3.0)
3. I want to override the PR's version with a major version bump, so I comment with /release-plz set-version <package>@<new-version>.
4. The comment-triggered workflow, first, should bump the package version, the set-version subcommand, and update the different project files.
5. The comment-triggered workflow, next, should commit the changes and force push them to the release PR. NB: The commit should be signed.
6. The command-triggered workflow, finally, should update the release PR title and description (e.g., text, links, etc.) accordingly.