pr-pdfs.yaml

name: Handle PDF pull request

on:
  pull_request:
    paths: '*.tex'

jobs:
  LaTeX:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Identify changed LaTeX documents
        env:
          pr_number: ${{ github.event.number }}
          base_sha: ${{ github.event.pull_request.base.sha }}
          head_sha: ${{ github.event.pull_request.head.sha }}
        run: |
          mergebase_sha=$(git merge-base $base_sha $head_sha)
          echo "mergebase_sha=$mergebase_sha" >> $GITHUB_ENV
          changed=$(git diff-tree --name-only --merge-base $base_sha $head_sha -- '*.tex' | tr '\n' ' ')
          echo "changed=$changed" >> $GITHUB_ENV
          echo "pdfs=$(ls -1 $changed | sed 's,^,new/,;s,tex$,pdf,' | tr '\n' ' ')" >> $GITHUB_ENV
          echo "diffs=$(ls -1 $changed | sed 's,^,diff/,;s,tex$,pdf,' | tr '\n' ' ')" >> $GITHUB_ENV

          echo "pr_number=$pr_number" > environ.txt
          echo "base_sha=$base_sha" >> environ.txt
          echo "head_sha=$head_sha" >> environ.txt
          echo "mergebase_sha=$mergebase_sha" >> environ.txt

      - name: Run LaTeX
        uses: ./.github/actions/texlive
        if:   ${{ env.changed }}
        with:
          run1: make ${{ env.pdfs }}
          run2: -make -k OLD=$mergebase_sha NEW=HEAD ${{ env.diffs }}

      - uses: actions/upload-artifact@v4
        with:
          name: pdf
          retention-days: 1
          if-no-files-found: ignore
          path: |
            environ.txt
            new/*.pdf
            diff/*.pdf