Add ability to leave a review comment

[renvrant]

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

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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:

github-repo-automation/src/lib/github.ts

Lines 480 to 490 in a046b29

	async approvePullRequest(pr: PullRequest) {
	const owner = this.repository.owner.login;
	const repo = this.repository.name;
	const url = `/repos/${owner}/${repo}/pulls/${pr.number}/reviews`;
	const result = await this.client.request({
	url,
	method: 'POST',
	data: {event: 'APPROVE'},
	});
	return result.data;
	}

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?