Add action to generate pdf diff #49
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| name: Generate Rendered Diff PDFs | |
| on: | |
| pull_request: | |
| types: [opened, synchronize, reopened] | |
| branches: | |
| - main | |
| permissions: | |
| contents: write | |
| issues: write | |
| pull-requests: write | |
| actions: read | |
| jobs: | |
| generate_pdfs: | |
| runs-on: ubuntu-latest | |
| outputs: | |
| files: ${{ steps.generate_files.outputs.files }} | |
| steps: | |
| - name: Checkout code | |
| uses: actions/checkout@v4 | |
| with: | |
| fetch-depth: 0 | |
| - name: Fetch main branch | |
| run: | | |
| git fetch origin main | |
| - name: Install dependencies | |
| run: | | |
| sudo apt-get update | |
| sudo apt-get install -y \ | |
| pandoc \ | |
| texlive-latex-base \ | |
| texlive-latex-extra \ | |
| texlive-fonts-recommended \ | |
| texlive-xetex \ | |
| texlive-fonts-extra \ | |
| latexdiff \ | |
| latexmk \ | |
| ghostscript | |
| - name: Generate PDF diffs | |
| id: generate_files | |
| shell: bash | |
| run: | | |
| git fetch origin main | |
| MODIFIED_FILES=$(git diff --name-only origin/main...HEAD -- '*.md') | |
| echo "Modified Markdown files:" | |
| echo "$MODIFIED_FILES" | |
| # Create necessary directories | |
| mkdir -p old_version new_version diffs pdfs | |
| # Create a custom LaTeX template | |
| TEMPLATE=.github/workflows/template/template.tex | |
| pandoc -D latex > default_template.tex | |
| TEMPLATE=default_template.tex | |
| for FILE in $MODIFIED_FILES; do | |
| echo "Processing $FILE" | |
| # Extract old version from main branch | |
| git show origin/main:"$FILE" > old_version/"$(basename "$FILE")" | |
| # Copy new version | |
| cp "$FILE" new_version/ | |
| # Convert both versions to LaTeX using the custom template | |
| pandoc old_version/"$(basename "$FILE")" --from markdown --to latex \ | |
| --template="$TEMPLATE" -o old_version/"$(basename "$FILE" .md)".tex | |
| pandoc new_version/"$(basename "$FILE")" --from markdown --to latex \ | |
| --template="$TEMPLATE" -o new_version/"$(basename "$FILE" .md)".tex | |
| # Run latexdiff with appropriate options | |
| latexdiff \ | |
| --encoding=utf8 \ | |
| old_version/"$(basename "$FILE" .md)".tex \ | |
| new_version/"$(basename "$FILE" .md)".tex \ | |
| > diffs/"$(basename "$FILE" .md)"_diff.tex | |
| # Compile the diffed LaTeX file to PDF using xelatex | |
| cd diffs | |
| latexmk -pdf -xelatex -interaction=nonstopmode -quiet -f "$(basename "$FILE" .md)"_diff.tex | |
| cd .. | |
| # Move the generated PDF to the pdfs directory | |
| mv diffs/"$(basename "$FILE" .md)"_diff.pdf pdfs/ | |
| done | |
| if [ -z "$MODIFIED_FILES" ]; then | |
| echo "files=[]" >> $GITHUB_OUTPUT | |
| else | |
| MODIFIED_FILES_JSON=$(printf '%s\n' "$MODIFIED_FILES" | jq -R . | jq -s .) | |
| # Use the correct syntax to write multi-line or complex outputs | |
| echo "files<<EOF" >> $GITHUB_OUTPUT | |
| echo "$MODIFIED_FILES_JSON" >> $GITHUB_OUTPUT | |
| echo "EOF" >> $GITHUB_OUTPUT | |
| fi | |
| - name: Upload PDFs | |
| uses: actions/upload-artifact@v4 | |
| if: steps.generate_files.outputs.files != '[]' # Only run if there are modified files | |
| with: | |
| name: document_changes | |
| path: pdfs/ | |
| retention-days: 90 | |
| - name: Comment on PR with download links | |
| uses: actions/github-script@v7 | |
| env: | |
| MODIFIED_FILES: ${{ steps.generate_files.outputs.files }} | |
| with: | |
| debug: true | |
| script: | | |
| const { issue, repo, sha } = context; | |
| const run_id = process.env.GITHUB_RUN_ID; | |
| // Unique identifier to find the bot's comment | |
| const botCommentIdentifier = '<!-- GENERATED_BY_GITHUB_ACTION_PDF_DIFF -->'; | |
| const modifiedFilesJSON = process.env.MODIFIED_FILES | |
| console.log("modifiedFilesJSON", modifiedFilesJSON); | |
| let modifiedFiles = []; | |
| try { | |
| modifiedFiles = JSON.parse(modifiedFilesJSON); | |
| } catch (error) { | |
| console.error("Failed to parse modified files:", error); | |
| } | |
| console.log("modifiedFiles", modifiedFiles); | |
| let body; | |
| if (modifiedFiles.length === 0) { | |
| // No artifacts were generated | |
| body = `${botCommentIdentifier}\n:warning: No rendered diff PDFs were generated because no Markdown files were modified.`; | |
| } else { | |
| // Construct the comment body | |
| body = `${botCommentIdentifier}\n:page_facing_up: Rendered diff PDFs have been generated for the following modified files:\n`; | |
| for (const modifiedFile of modifiedFiles) { | |
| body += `- ${modifiedFile}\n`; | |
| } | |
| // Add a comment about how to download in case links expire | |
| const artifactUrl = `https://github.com/${repo.owner}/${repo.repo}/actions/runs/${run_id}#artifacts`; | |
| body += `\n**Note**: You can download these files from the [Artifacts section of the workflow run](${artifactUrl}).`; | |
| body += "\nThese files expire after 90 days." | |
| // Add a commend about how to read latexdiff | |
| body += "\n\n**How to read these PDFs**:\n" | |
| body += "- Added text is wavy underlined and blue.\n" | |
| body += "- Discarded text is struck out and red.\n" | |
| } | |
| body += `\n_Last updated at ${new Date().toUTCString()} for commit ${sha.substring(0, 7)}_`; | |
| console.log("Listing comments for ", { | |
| owner: repo.owner, | |
| repo: repo.repo, | |
| issue_number: issue.number, | |
| }); | |
| // Fetch existing comments on the PR | |
| const { data: comments } = await github.rest.issues.listComments({ | |
| owner: repo.owner, | |
| repo: repo.repo, | |
| issue_number: issue.number, | |
| }); | |
| // Find the comment made by the bot with the identifier | |
| const botComment = comments.find( | |
| comment => | |
| comment.user.login === 'github-actions[bot]' && | |
| comment.body.includes(botCommentIdentifier) | |
| ); | |
| if (botComment) { | |
| console.log("Found existing comment. Updating"); | |
| // Update the existing comment | |
| await github.rest.issues.updateComment({ | |
| owner: repo.owner, | |
| repo: repo.repo, | |
| comment_id: botComment.id, | |
| body: body, | |
| }); | |
| } else { | |
| console.log("No existing comment. Creating new"); | |
| // Create a new comment | |
| await github.rest.issues.createComment({ | |
| owner: repo.owner, | |
| repo: repo.repo, | |
| issue_number: issue.number, | |
| body: body, | |
| }); | |
| } |