Add ability to leave a review comment

[renvrant]

Thanks for stopping by to let us know something could be better!

PLEASE READ: If you have a support contract with Google, please create an issue in the support console instead of filing on GitHub. This will ensure a timely response.

Is your feature request related to a problem? Please describe. This tool is extremely useful for managing dependencies across many repositories. However, in order to fully control dependency update tools like dependabot, you need to be able to leave review comments. These comments can order the bot to rebase, recreate, or ignore given dependency updates, which is pretty integral for managing a dependency update across many repos with varying degrees of commit traffic and general up-to-date-ness. You can see Dependabot Comments and Options in this demo repo for an example. Describe the solution you'd like Add a command to comment on PRs that match a given title Describe alternatives you've considered Forking or patching this repo to add this feature? 😅 Additional context N/A

[alexander-fenster]

Seems like a good idea! We never need it because we manage our bots using labels, but I can see how being able to leave review comment could be useful. The code change should not be hard, if I'm reading correctly, we'll need to pass a comment text here:

https://github.com/googleapis/github-repo-automation/blob/a046b295487d5da45597d26110effad0c15982ad/src/lib/github.ts#L480-L490

as a body (API call documentation: https://docs.github.com/en/rest/pulls/reviews), and we can take it from the command line and probably add an optional parameter to processPRs.

Feel free to send a pull request :) I might be able to find some time and implement it, but I cannot promise that I can do it soon.

[alexander-fenster]

Since we are starting using Cloud Build more and might want to mass-comment PRs with /gcbrun, let's maybe consider this?