name: Check docs up-to-date
on:
  push:
    branches: ["main"]
    paths:
      - 'book/**'
      - 'docs/**'
      - '.gitignore'
      - 'Makefile'
      - '.github/workflows/book.yml'
  pull_request:
    branches: ["main"]
    types: [opened, synchronize]
    paths:
      - 'book/**'
      - 'docs/**'
      - '.gitignore'
      - 'Makefile'
      - '.github/workflows/book.yml'

jobs:
  check-docs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with: { fetch-depth: 0 }

      - name: Install and test the mdBook
        run: make test-book

      - name: Build book
        run: mdbook build book

      - name: Build book to tmp
        run: mdbook build book -d docs-tmp

      - name: Compare with committed docs
        run: |
          if ! diff -r docs-tmp docs 2>/dev/null; then
            echo "docs/ is not up-to-date. Run make test-book and commit the docs/ directory"
            exit 1
          fi