render_readme.yml

# Name of the workflow
name: render-readme

# Controls when the action will run. Triggers include:
# 
# - button trigger from github action page
# - on changes to readme.Rmd

on:
  workflow_dispatch:
  push:
    paths:
      - 'README.Rmd'

# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
  render-readme:
    runs-on: macos-latest
    env:
      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout repos
        uses: actions/checkout@v2

      - name: Setup R
        uses: r-lib/actions/setup-r@v2
        with:
          use-public-rspm: true

      - name: Setup pandoc
        uses: r-lib/actions/setup-pandoc@v2
    
      - name: Install dependencies
        uses: r-lib/actions/setup-r-dependencies@v2
        with:
          extra-packages: any::rmarkdown, local::.
 
      - name: Compile the readme
        run: |
          tf <- tempfile(fileext = ".Rmd")
          writeLines(
            knitr::knit_expand(
              "README.Rmd", 
              packagename = read.dcf("DESCRIPTION", "Package"), 
              gh_repo = Sys.getenv("GITHUB_REPOSITORY")
            ), 
            tf
          )
          rmarkdown::render(tf, output_file = "README.md", output_dir = ".")
        shell: Rscript {0}
        
      - name: Commit files
        run: |
          git config --local user.email "action@github.com"
          git config --local user.name "GitHub Action"
          git add README.md
          # Also add README figures if they exist
          if [ -d man/figures ]
          then
            git add man/figures/
          fi
          git diff-index --quiet HEAD || git commit -m "Automatic readme update"
          git push origin || echo "No changes to push"