Edge case: draft PR marked as S-waiting-on-author receives S-waiting-on-review on undraft in addition instead of flip

[jieyouxu]

Summary

Un-drafting a PR should cause existing S-waiting-on-author label to be replaced by S-waiting-on-review and not have both co-exist.

Example: rust-lang/rust#142357

Repro steps

• Open non-draft PR (no S-waiting-on-* labels by default)
• @rustbot author -> PR receives S-waiting-on-author
• Mark PR as draft
• Undraft PR -> PR receives S-waiting-on-review but S-waiting-on-author isn't removed.

Current behavior

Both S-waiting-on-{author,review} labels are present.

Expected behavior

Only one of S-waiting-on-{author,review} labels are present; should become S-waiting-on-review on un-draft.

[Urgau]

[autolabel] doesn't currently have any handling for the draft state, but we do for "new PR", opened #2104 to address it with a new new_draft state for labels.

[apiraino]

Undraft PR -> PR receives S-waiting-on-review but S-waiting-on-author isn't removed.

Do we have a check on labels so that these two are mutually exclusive? Would that solve the issue at the root?

[jieyouxu]

Undraft PR -> PR receives S-waiting-on-review but S-waiting-on-author isn't removed.

Do we have a check on labels so that these two are mutually exclusive? Would that solve the issue at the root?

Another edge case is that you can manually apply labels, so it doesn't have to be perfect

[apiraino]

Another edge case is that you can manually apply labels

Both of them at the same time or did you mean something else? (I'm sorry maybe I didn't understand your comment)

[jieyouxu]

Another edge case is that you can manually apply labels

Both of them at the same time or did you mean something else? (I'm sorry maybe I didn't understand your comment)

Yeah, it's possible to apply both at the same time (for instance, unintentionally, or github label ui racing with urself)