name: Changed formatters
on: [pull_request]
jobs:
  formatters:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout pull request
        uses: actions/checkout@v2
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Fetch master
        run: |
          git fetch
      - name: Test changed formatters
        run: |
          set -euo pipefail

          mkdir -p .tmp
          make docker CMD="make fmt-changed > .tmp/changed"
          export FORMATTERS="$(< .tmp/changed)"
          if [[ -n "${FORMATTERS}" ]]; then
              make fmt-build fmt-docker CMD="make fmt-test"
          fi