pr-slide-check.yaml

# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
# Source version of this workflow lives in https://github.com/slds-lmu/lecture_service
# Please only update by copying from there to avoid divergences
# - attempts slide compilation
# - compares compiled slides against slides-pdf/
# - compiles a markdown tables and appends it to the pull request that triggered it.
# .. for only this particular lecture repo.
on:
  workflow_dispatch:
  pull_request:
    paths: ['style/**', 'slides/**', 'latex-math/**']

name: pr-slide-check

jobs:
  pr-slide-check:
    runs-on: ubuntu-latest
    env:
      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
    permissions:
      pull-requests: write # Write to PRs
    steps:
      # Clone lecture checker repo in the current directory
      # We need lecture repo to be a sub directory of this for reasons (can optimize this once stable + working)
      - name: Checkout lecture service repo
        uses: actions/checkout@v4
        with:
          repository: slds-lmu/lecture_service

      # Most reliable way I've found to get the repo name and use it as a parameter for the checkout action
      # see https://stackoverflow.com/a/75513916/409362
      # If the repo is named slds-lmu/lecture_i2ml, we only need the "lecture_i2ml" part.
      - name: Save repository name to env var (without org)
        id: repo-basename
        run: |
          echo "value=$(basename ${{ github.repository }})" >> $GITHUB_OUTPUT
        shell: bash

      - name: Checkout this lecture repo
        uses: actions/checkout@v4
        with:
          # Clone lecture repo in subdirectory of the same name
          path: ${{ steps.repo-basename.outputs.value }}
          # translates to e.g.: path: "lecture_i2ml"
          # No need for git history
          # 0 indicates all history for all branches and tags, 1 is shallow (and default)
          fetch-depth: 1

      # Standard R/pandoc/latex setup steps
      - uses: r-lib/actions/setup-pandoc@v2
      - uses: r-lib/actions/setup-r@v2
        with:
          use-public-rspm: true
      - uses: r-lib/actions/setup-tinytex@v2
      - run: tlmgr --version
      # Caching the R library requires to save its path beforehand, could hard-code but meh
      - name: Get R library dir for caching
        id: r-cache
        run: |
          echo "dir=$(Rscript --quiet -e 'cat(.libPaths()[[1]])')" >> $GITHUB_OUTPUT
      - name: Restore R package cache
        uses: actions/cache@v3
        with:
          path: ${{ steps.r-cache.outputs.dir }}
          key: ${{ runner.os }}-r-${{inputs.cache-version }}-${{ hashFiles('scripts/install_r_deps.R') }}
          restore-keys: ${{ runner.os }}-r-${{inputs.cache-version }}-

      # Setting up the lecture checking requirements:
      # 1) R packages
      - name: Install R packages
        run: make install-r
      # 2) latex dependencies, incl output list of installed pkgs (optional)
      - name: Install additional LaTeX packages
        run: |
          make install-tex
          tlmgr list --only-installed
      # 3) Installing diff-pdf and diff-pdf-visually (only automated for ubuntu so far)
      - name: Install diff-pdf and diff-pdf-visually
        run: make install-tools-ubuntu

      - name: Install the service package
        run: make install-service

      # Uncomment / move to get a tmux ssh session for interactive debugging
      # - name: Setup tmate session
      #   uses: mxschmitt/action-tmate@v3

      # Run the main thing: compiles slides, checks against slides-pdf/*
      - name: Check slides and build markdown table
        run: make table

      # Take the markdown document with the tables rendered in the previous step
      # and add it as a comment to the PR that triggered this action.
      # The comment_tag is there such that the comment can be updated after
      # a potential re-run of the action.
      # https://github.com/thollander/actions-comment-pull-request
      - name: PR comment with file
        uses: thollander/actions-comment-pull-request@v2
        with:
          filePath: slide_status_pr.md
          comment_tag: slide_check