changelog.yml

name: Changelog
on:
  pull_request:
    types: [opened, synchronize, reopened, labeled, unlabeled]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          # We want to check modified files from base_ref (merge target) to the current commit,
          # so we need the full history of the current branch.
          fetch-depth: 0

      - name: Check for skip label
        id: check-skip
        run: |
          if [[ "${{ contains(github.event.pull_request.labels.*.name, 'skip-changelog') }}" == "true" ]]; then
            echo "skip=true" >> $GITHUB_OUTPUT
            echo "Skipping changelog validation due to skip-changelog label"
          else
            echo "skip=false" >> $GITHUB_OUTPUT
          fi

      - name: Validate changelog entry
        if: steps.check-skip.outputs.skip == 'false'
        run: |
          # --quiet implies --exit-code (but doesn't produce output).
          # --exit-code exits 1 if there are differences, or 0 if there are no differences.
          # So: this command exits 1 if CHANGELOG.md was changed between the base and HEAD,
          # or 0 if there are no diffs.
          if git diff --quiet origin/"${{ github.base_ref }}"...HEAD -- CHANGELOG.md; then
            echo "::error::No changelog entry found. Please add an entry to CHANGELOG.md or add the 'skip-changelog' label if this change does not require a changelog entry."
            exit 1
          else
            echo "Changelog has been updated"
          fi