[Kaivo]

But that only works well if the PR is up to date with the targeted branch.

AFAIK, you have to manually merge the targeted branch into the PRs to be in an equivalent situation. Also, other commits might still be added into the targeted branch between the time the tests have been run and the PR is merged.

[wfunction]

Oh I see, so the problem is that the merge commit is not the same as the one that the test runs for if there are any intervening commits between them. Interesting, I didn't quite realize that! (Though it seems obvious in hindsight, since a new push doesn't make all past PRs' tests re-run.) Thanks for explaining that! So it seems it's something between what they do and what they were trying to avoid. GitHub should really put a button to re-run tests on merges that are out of date...