Merge pull request #971 from ehuss/merge-queue-workflow

Prepare CI workflows to support merge queues.

.github/workflows/main.yml

@@ -1,5 +1,7 @@
 name: CI
-on: [push, pull_request]
+on:
+ pull_request:
+ merge_group:
 
 jobs:
  test:
@@ -42,3 +44,43 @@ jobs:
  - name: Install Rust
  run: rustup update stable && rustup default stable && rustup component add rustfmt
  - run: cargo fmt -- --check
+
+ # These success/failure jobs are here to consolidate the total
+ # success/failure state of all other jobs. These jobs are then included in
+ # the GitHub branch protection rule which prevents merges unless all other
+ # jobs are passing. This makes it easier to manage the list of jobs via this
+ # yml file and to prevent accidentally adding new jobs without also updating
+ # the branch protections.
+ #
+ # Unfortunately this requires two jobs because the branch protection
+ # considers skipped jobs as successful. The status check functions like
+ # success() can only be in an `if` condition.
+ #
+ # Beware that success() is false if any dependent job is skipped. See
+ # https://github.com/orgs/community/discussions/45058. This means there
+ # cannot be optional jobs. One workaround is to check for all other
+ # statuses:
+ # (contains(needs.*.result, 'cancelled') || contains(needs.*.result, 'skipped') || contains(needs.*.result, 'failure'))
+ # but that is a mess.
+ success:
+ name: Success gate
+ runs-on: ubuntu-latest
+ needs:
+ - test
+ - rustfmt
+ if: "success()"
+ steps:
+ - name: mark the job as a success
+ run: echo success
+ failure:
+ name: Failure gate
+ runs-on: ubuntu-latest
+ needs:
+ - test
+ - rustfmt
+ if: "!success()"
+ steps:
+ - name: mark the job as a failure
+ run: |
+ echo One or more jobs failed
+ exit 1