Make "Merge when ready" button always "work"

[MikeMcQuaid]

What were you trying to do (and why)?

It would be nice if the Homebrew/homebrew-core "Merge when ready" button always "just worked" i.e. it would intelligently know to push bottle commits to the PR if necessary and then attempt another merge later.

What happened (include all command output)?

People click the "merge when ready" button and it does the wrong thing e.g. not merge, not include bottles, etc.

What did you expect to happen?

The "merge when ready" button always merges when ready.

Step-by-step reproduction instructions (by running brew commands)

• Press "merge when ready"
• Sometimes: it does not do what you want/expect

[Bo98]

Alternative thought: given merging requires approval, and approving itself triggers an automerge, we could make a status check that only passes once the bottle commit is added (or otherwise doesn't require a bottle commit) so that adding to the merge queue doesn't happen until that point.

[carlocab]

Alternative thought: given merging requires approval, and approving itself triggers an automerge, we could make a status check that only passes once the bottle commit is added (or otherwise doesn't require a bottle commit) so that adding to the merge queue doesn't happen until that point.

Yes, @MikeMcQuaid had suggested this previously.

It's not my preferred solution since it makes status indicators on the PR list less informative. i.e. We don't know if a PR has an ❌ because it's failing or because it just has no bottles yet.

[Bo98]

Alternative thought: given merging requires approval, and approving itself triggers an automerge, we could make a status check that only passes once the bottle commit is added (or otherwise doesn't require a bottle commit) so that adding to the merge queue doesn't happen until that point.

Yes, @MikeMcQuaid had suggested this previously.

It's not my preferred solution since it makes status indicators on the PR list less informative. i.e. We don't know if a PR has an ❌ because it's failing or because it just has no bottles yet.

I would probably make it 🟡 rather than ❌ so failures show but yeah point noted for the ✅ case.

[carlocab]

Yea, 🟡 is a lot more reasonable, and I would no longer opposed to it if we used 🟡. It would take some getting used to, though (but I can live with it if that's what others wanted to do).

[MikeMcQuaid]

I think having "this PR is ready to be added to the merge queue" indicated with 🟢 rather than 🟡 or 🔴 is a much nicer experience.

[carlocab]

I think having "this PR is ready to be added to the merge queue" indicated with 🟢 rather than 🟡 or 🔴 is a much nicer experience.

This is ready to go at #173010. Just needs another review since I had to rework the approach.