Slack notifications: to author, committer, pusher if different

[smondet]

Right now I think the only the commit author gets notified:

monorobot/lib/action.ml

Line 174 in 9fd5f87

let email = n.commit.commit.author.email in

But it can make sense to (also) notify the committer (often latest user to rebase?) and/or the pusher (I don't know if github gives that information).

[thatportugueseguy]

Can you elaborate on the usecase/situation that prompted you to open the issue?

The thing with the notifications is that we need to notify as few people as possible and as less often as possible, otherwise people just mute everything and they serve no purpose.

[smondet]

• Person A: writes the commit, it's all green, but it is in a “staging” branch
• Person B: rebases, and merges into the prod-branch, but breaks the CI.

right now Person A gets notified while it's Person B who actually broke the CI (unless Person B changes the author-field of the commit while rebasing which is not the default)

it has happened that Person A and Person B work in very different timezones so e.g. Person A wakes up hours later to a CI-broken notification

[thatportugueseguy]

Ok, it makes sense that there are cases where the committer or the pusher might not be the same as the author, and in those cases, we want to notify all the interveners. Thanks!