build_preview.yml

name: Build PR preview

on:
  pull_request:
    types:
      - opened
      - reopened
      - synchronize

concurrency: 
  group: preview-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build-preview:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - uses: actions/setup-python@v2
        with:
          python-version: 3.x

      - name: Install dependencies
        run: pip install -r requirements.txt

      - name: Build
        # builds to "site" directory by default
        run: |
          mkdocs build -f mkdocs.yml -d site

      - name: Save PR number
        run: |
          mkdir -p ./pr
          echo ${{ github.event.number }} > ./pr/NB
      - uses: actions/upload-artifact@v2
        with:
          name: pr
          path: pr/

      - name: Save built site
        run: |
          mkdir -p ./pr_site
          mv site ./pr_site/.
      - uses: actions/upload-artifact@v2
        with:
          name: pr_site
          path: pr_site/