check-changelog.yml

name: Check Changelog
on:
  pull_request:
    types: [ opened, synchronize, labeled, unlabeled ]
jobs:
  check-changelog:
    runs-on: [ubuntu-latest]
    steps:
      - name: Checkout
        uses: actions/checkout@v3.3.0

      - name: Find Changed Files in changelog.d
        id: changed-files
        uses: tj-actions/changed-files@v35
        with:
          files: '**/changelog.d/**'

      - name: Enforce New File or 'No Changelog Required' Label
        uses: actions/github-script@v6
        # don't require changelogs for draft PRs
        if: github.event.pull_request.draft == false
        with:
          script: | 
            function shouldCheckChangelog() {
              return !${{ contains(github.event.pull_request.labels.*.name, 'No Changelog Required') }};
            }

            function getNewChangelogFiles() {
              const newFiles = '${{ steps.changed-files.outputs.added_files }}'.trim().split(' ');
              // We check that added_files is the singleton array containing the empty string.
              // This is probably a bug in tj-actions/changed-files
              if (newFiles.length === 1 && newFiles[0] === "") {
                return [];
              } else {
                return newFiles;
              }
            }

            function checkChangelog() {
              const newFiles = getNewChangelogFiles();
              if (newFiles.length == 0) {
                core.info("No files were added by this PR in any of the **/changelog.d directories.");
                core.info("Either commit a new file, or add the label 'No Changelog Required' to your PR.");
                core.setFailed("Changelog check failed.");
              } else {
                core.info(`The following changelog files were added by this PR:\n${newFiles}`);
              }
            }

            if (shouldCheckChangelog()) {
              checkChangelog();
            } else {
              core.info("PR contains the label 'No Changelog Required', skipping changelog check.");
            }