deploy.yml

# A workflow to update the online issues lists.

name: Generate HTML pages

on:
  # This job must only be run when changes are pushed to the master branch!
  push:
    branches: [ master ]

jobs:
  update-html-pages:
    runs-on: ubuntu-latest

    steps:
    - name: Use cached git repo
      # Try to use a cached copy of the repository to avoid cloning it again
      # and then regenerating the meta-data/dates file from scratch (slow!)
      id: cache-repo
      uses: actions/cache@v3
      with:
        path: |
          .git
          xml
          meta-data
          src
        key: cached-repo

    - if: ${{ steps.cache-repo.outputs.cache-hit == 'true' }}
      # Using cached git repo, so sync with the latest changes.
      name: Update cached repo
      run: |
        # Make sure we are in a clean worktree on the right branch.
        git reset --hard HEAD
        git checkout master
        # Fetch changes since the cache was saved.
        git fetch
        # Update timestamp of this file so only issue files that get
        # changed by the next command will be newer than it.
        touch meta-data/dates
        # Do a hard reset instead of merge, just in case there has been
        # a force push since the cache was last updated.
        git reset --hard @{u}

    - if: ${{ steps.cache-repo.outputs.cache-hit != 'true' }}
      # Not using cached git repo, so clone it (with full history).
      uses: actions/checkout@v3
      with:
        fetch-depth: 0

    - name: Update issue timestamps
      run: make dates

    - name: Generate HTML lists
      run: make lists

    # We need a fresh repo that has valid credentials to push to gh-pages.
    - name: Clone repo again in order to push
      uses: actions/checkout@v3
      with:
        ref: 'gh-pages'
        path: 'gh-pages'
        clean: 'false'

    - name: Update online pages
      run: |
        : Push new HTML files to gh-pages branch
        mv mailing/*.html gh-pages/
        rmdir mailing
        cd gh-pages
        git config user.name "github-actions"
        git config user.email "github-actions@github.com"
        # Stage any changes to the individual issues (including new files):
        git add issue*.html
        # This only compares the staged changes, so ignores new timestamps
        # in the lwg-*.html files. The commit -a will pick those up though.
        printf '\nChecking HTML issues for changes ...\n'
        if git diff --cached --exit-code ; then
          echo 'No changes, not publishing new lists.'
        else
          printf '\nCommitting the changes above:\n'
          git commit -a -m 'Automatic update from GitHub Actions workflow'
          printf '\nPushing to the gh-pages branch:\n'
          git push
        fi
        cd ..