message: Fix coverage diffs for PRs that aren't up to date, take 2
diff: @@ -16,7 +16,7 @@ jobs:
  # If this is a pull request, make sure we check out its head rather than the
  # automatically generated merge commit, so that the coverage diff excludes
  # unrelated changes in the base branch
  - ref: ${{ github.event.type == 'PullRequestEvent' && github.event.pull_request.head.sha || '' }}
  + ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || '' }}
  - name: Yarn cache
  uses: c-hive/gha-yarn-cache@v2
  