I use excalidraw to manage my diagrams for my blog

name: Export Excalidraw Frames

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

permissions:
  contents: write

jobs:
  export-frames:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 2  # Fetch last 2 commits to compare with HEAD~1

      - name: Get changed Excalidraw files
        id: changed-files
        run: |
          # Get list of changed .excalidraw files since last commit
          if [[ "${{ github.event_name }}" == "push" ]]; then
            CHANGED_FILES=$(git diff --name-only HEAD~1 HEAD | grep '\.excalidraw$' || true)
          else
            # For PRs, compare with target branch
            CHANGED_FILES=$(git diff --name-only origin/${{ github.base_ref }} HEAD | grep '\.excalidraw$' || true)
          fi

          if [ -z "$CHANGED_FILES" ]; then
            echo "No changed .excalidraw files found"
            echo "has_changes=false" >> $GITHUB_OUTPUT
          else
            echo "Changed files:"
            echo "$CHANGED_FILES"
            echo "$CHANGED_FILES" > /tmp/changed_files.txt
            echo "has_changes=true" >> $GITHUB_OUTPUT
          fi

      - name: Install excalirender
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          curl -fsSL https://raw.githubusercontent.com/JonRC/excalirender/main/install.sh | sh
          echo "$HOME/.local/bin" >> $GITHUB_PATH
          excalirender --version || echo "excalirender installed"

      - name: Export frames for changed files
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          # Create export script
          cat > /tmp/export_frames.sh << 'EOF'
          #!/bin/bash

          EXCALIDRAW_FILE="$1"
          OUTPUT_DIR="$(dirname "$EXCALIDRAW_FILE")"

          # Read the Excalidraw file and extract frame names
          FRAME_NAMES=$(jq -r '.elements[] | select(.type == "frame") | .name // "frame-" + .id' "$EXCALIDRAW_FILE")

          if [ -z "$FRAME_NAMES" ]; then
            echo "No frames found in $EXCALIDRAW_FILE"
            exit 0
          fi

          echo "Exporting frames from $EXCALIDRAW_FILE"

          # Export each frame in light and dark mode
          while IFS= read -r frame_name; do
            if [ -n "$frame_name" ]; then
              echo "  Exporting frame: $frame_name"

              # Sanitize frame name for use in filename
              safe_name=$(echo "$frame_name" | sed 's/[<>:"/\\|?*]/-/g' | sed 's/\s+/-/g')

              # Export light mode
              excalirender "$EXCALIDRAW_FILE" --frame "$frame_name" -o "${OUTPUT_DIR}/${safe_name}-light.svg"

              # Export dark mode
              excalirender "$EXCALIDRAW_FILE" --frame "$frame_name" --dark -o "${OUTPUT_DIR}/${safe_name}-dark.svg"
            fi
          done <<< "$FRAME_NAMES"

          echo "  ✓ Exported all frames from $EXCALIDRAW_FILE"
          EOF

          chmod +x /tmp/export_frames.sh

          # Process each changed file
          while IFS= read -r file; do
            if [ -n "$file" ]; then
              echo "Processing: $file"
              /tmp/export_frames.sh "$file"
            fi
          done < /tmp/changed_files.txt

      - name: Commit exported SVGs
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          git config --local user.email "github-actions[bot]@users.noreply.github.com"
          git config --local user.name "github-actions[bot]"

          # Add all newly created SVG files
          git add **/*.svg 2>/dev/null || git add *.svg 2>/dev/null || true

          # Check if there are any changes to commit
          if git diff --staged --quiet; then
            echo "No new SVG files to commit"
          else
            echo "Committing exported SVG files"
            git commit -m "chore: export Excalidraw frames as SVGs

            - Exported frames from changed .excalidraw files
            - Generated light and dark mode variants

            🤖 Generated with [Claude Code](https://claude.com/claude-code)

            Co-Authored-By: Claude <noreply@anthropic.com>"
            git push
          fi