Commit queue and unsquashed commits

[mscdex]

I've seen this occur a few times in recent times where PRs are landed with the "commit queue" feature without the commits being squashed first.

What if the github bot required some kind of explicit "approval" or something similar before a PR with the commit queue label applied with multiple commits in it could be landed? That way it wouldn't be as easy as simply adding the label to push a bunch of unsquashed commits.

[targos]

A few examples: #40344, #40348, #40128

[Flarna]

It would be nice to tell bot to squash commits even the extra commits are no fixup commits.

[mscdex]

I think the problems with having the bot squash commits would at least include:

• Not knowing what should go in the squashed commit message.
• Knowing which (or if all) commits really should be squashed. There are some cases (although not as common relatively speaking) where you really do want to keep the commits currently in the PR.

[mhdawson]

@mscdex, I think we could require manual landing in the case where you wanted to keep multiple commits

In terms of what should go into the squashed commit message I think I'd keep it to the message in the original commit as that is most often what would make sense.

Having said that, the original suggestion of an approval makes sense to me.

Maybe as a quick fix, just preventing the queue from landing a PR with multiple commits would be a good first step.

[tniessen]

It would be nice to tell bot to squash commits even the extra commits are no fixup commits.

To add to this, our guides say that

All commits should be self-contained, meaning every commit should pass all tests.

and this is not true for some of the unsquashed commits landed through the commit queue.

[aduh95]

nodejs/node-core-utils#572 is ready for reviews, should improve the situation. The plan would be to make the CQ fail by default when trying to land several commits.
We could decide to add commit-queue-fixupAll and commit-queue-land-multiple-commits to allow to land PR with multiple commits, or decide that this is better to manual landing.