update-book.yml

name: Update Progit Book

on:
  workflow_dispatch:
  schedule:
    # check daily for updates
    - cron: '29 4 * * *'
  push:

permissions:
  contents: write # need to be able to push

env:
  # Install also the gems needed to run the `update-book2.rb` script
  BUNDLE_WITH: scripts

jobs:
  check-for-updates:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          sparse-checkout: |
            _sync_state
            script
      - uses: actions/github-script@v6
        id: get-pending
        with:
          script: |
            const { getPendingBookUpdates } = require('./script/ci-helper.js')

            const pending = await getPendingBookUpdates(github)
            // an empty matrix is invalid and makes the workflow run fail, unfortunately
            return pending.length ? pending : ['']
      - name: ruby setup
        # Technically, we do not need Ruby in this job. But we do want to cache
        # Ruby & The Gems for use in the matrix in the next job.
        if: steps.get-pending.outputs.result != '[""]'
        uses: ruby/setup-ruby@v1
        with:
          bundler-cache: true
    outputs:
      matrix: ${{ steps.get-pending.outputs.result }}
  update-book:
    needs: check-for-updates
    if: needs.check-for-updates.outputs.matrix != '[""]'
    runs-on: ubuntu-latest
    strategy:
      matrix:
        language: ${{ fromJson(needs.check-for-updates.outputs.matrix) }}
      fail-fast: false
    steps:
      - uses: actions/checkout@v3
        with:
          sparse-checkout: |
            _sync_state
            script
            _data
            book/${{ matrix.language.lang }}
      - name: ruby setup
        uses: ruby/setup-ruby@v1
        with:
          bundler-cache: true
      - name: update book/${{ matrix.language.lang }}
        shell: bash
        run: |
          # Clone the book's sources
          git clone --depth 1 --single-branch \
            https://github.com/${{ matrix.language.repository }} progit-clone &&

          # this seems to be needed to let `bundle exec` see `vendor/bundle/`
          { bundle check || bundle install --frozen; } &&

          # generate the HTML
          bundle exec ruby ./script/update-book2.rb ${{ matrix.language.lang }} progit-clone &&

          # record the commit hash
          mkdir -p _sync_state &&
          git -C progit-clone rev-parse HEAD >_sync_state/book-${{ matrix.language.lang }}.sha &&

          # commit it all
          printf '%s\n' /progit-clone/ /vendor >>.git/info/exclude &&
          git add \
            _sync_state \
            _data/book-${{ matrix.language.lang }}.yml \
            book/${{ matrix.language.lang }} &&
          git -c user.name=${{ github.actor }} \
            -c user.email=${{ github.actor }}@noreply.github.com \
            commit -m 'book: update ${{ matrix.language.lang }}' \
              -m 'Updated via the `update-book.yml` GitHub workflow.' &&

          # verify that there are no uncommitted changes
          git update-index --refresh &&
          if test -n "$(git diff HEAD)$(git ls-files --exclude-standard --other)"
          then
            echo '::error::there are uncommitted changes!' >&2
            git status >&2
            exit 1
          fi &&

          # generate the bundle
          git branch -m book-${{ matrix.language.lang }}
          git bundle create ${{ matrix.language.lang }}.bundle HEAD^..book-${{ matrix.language.lang }}
      - uses: actions/upload-artifact@v3
        with:
          name: bundle-${{ matrix.language.lang }}
          path: ${{ matrix.language.lang }}.bundle
  push-updates:
    needs: [check-for-updates, update-book]
    if: needs.check-for-updates.outputs.matrix != '[""]'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          sparse-checkout: .
      - uses: actions/download-artifact@v3
      - name: push updates
        shell: bash
        run: |
          for bundle in bundle-*/*.bundle
          do
            lang=${bundle##*/}
            lang=${lang%.bundle}

            git -c core.editor=: \
              -c user.name=${{ github.actor }} \
              -c user.email=${{ github.actor }}@noreply.github.com \
              pull --no-rebase $bundle book-$lang ||
            exit 1
          done

          git push origin HEAD