deploy.yml

name: Deploy

on:
  push:
    branches: [ main ]

jobs:
  validate:
    uses: "./.github/workflows/validate.yml"

  # GitHub Actions does not have a halt job option to stop from deploying if no functional changes were found.
  # We thus execute a separate deployment job depending on the output of this job.
  check-for-functional-changes:
    runs-on: ubuntu-22.04
    outputs:
      status: ${{ steps.stop-early.outputs.status }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0 # Fetch all the tags
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: 3.9.12
      - id: stop-early
        run: |
          if "${GITHUB_WORKSPACE}/.github/has-functional-changes.sh"
          then 
            echo "status=success" >> $GITHUB_OUTPUT
          fi

  check-pypi-token: # Use intermediary job as secrets cannot be directly referenced in `if:` conditionals; see https://docs.github.com/en/actions/security-guides/using-secrets-in-github-actions#using-secrets-in-a-workflow
    runs-on: ubuntu-22.04
    outputs:
      pypi_token_present: ${{ steps.check_token.outputs.pypi_token_present }}
    steps:
      - name: Check PyPI token is defined
        id: check_token
        run: |
          if [[ -n "${{ secrets.PYPI_TOKEN }}" ]]
          then
            echo "pypi_token_present=true" >> $GITHUB_OUTPUT
          else
            echo "pypi_token_present=false" >> $GITHUB_OUTPUT
          fi
      
  deploy:
    runs-on: ubuntu-22.04
    needs: [ validate, check-for-functional-changes, check-pypi-token ]
    if: needs.check-for-functional-changes.outputs.status == 'success' && needs.check-pypi-token.outputs.pypi_token_present == 'true'
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: 3.9.12
      - name: Restore build
        uses: actions/cache@v4
        with:
          path: ${{ env.pythonLocation }}
          key: build-${{ env.pythonLocation }}-${{ hashFiles('pyproject.toml') }}-${{ github.sha }}
      - name: Restore built package
        uses: actions/cache@v4
        with:
          path: dist
          key: release-${{ env.pythonLocation }}-${{ hashFiles('pyproject.toml') }}-${{ github.sha }}
      - name: Upload a Python package to PyPi
        run: twine upload dist/* --username __token__ --password ${{ secrets.PYPI_TOKEN }}
      - name: Publish a git tag
        run: "${GITHUB_WORKSPACE}/.github/publish-git-tag.sh"