build_documentation.yaml

# GitHub Actions workflow to build and deploy Sphinx documentation to GitHub Pages
name: Docs

# Trigger the workflow on pushes, pull requests, or manual dispatch events
on:
  push:              # 1. Rebuild docs on every push to any branch
  pull_request:      # 2. Also run on every pull request
  workflow_dispatch: # 3. Allow manual triggers from the GitHub UI

permissions:
  contents: write   # Required so the deploy step can push to gh-pages

jobs:
  docs:
    runs-on: ubuntu-latest   # Use the latest Ubuntu runner provided by GitHub
    steps:
      # 1. Check out the repository contents
      - name: Checkout repository
        uses: actions/checkout@v3

      # 2. Set up a Python environment (defaults to latest 3.x)
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"

      # 3. Install Sphinx and its themes/extensions
      - name: Install dependencies
        run: |
          pip install sphinx sphinx_rtd_theme sphinx-copybutton
          pip install -e .

      # 4. Build the HTML documentation
      - name: Build Sphinx docs
        run: |
          sphinx-build doc _build

      # 5. Deploy the docs to the gh-pages branch (only on push to master)
      - name: Deploy
        uses: peaceiris/actions-gh-pages@v3
        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
        with:
          publish_branch: gh-pages         # Target branch for the published site
          github_token: ${{ secrets.GITHUB_TOKEN }} # Auth token provided by GitHub
          publish_dir: _build/             # Directory containing the built HTML
          force_orphan: true               # Create branch history from scratch each deployment