The Complete Production SOP: How to Deploy and Run Danger JS Pull Request Rules & Automated Review Comments in Autonomous AI Agents

---
name: "danger-js-pull-request-automation"
description: "Enforce pull request conventions, changelog updates, and size checks using Danger JS."
metadata:
  author: "Danger Systems"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "write dangerfile.ts"
  - "enforce pr changelog danger"
  - "warn large pull requests danger"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

# Danger JS Pull Request Rules & Automated Review Comments
Authors Danger JS rules in dangerfile.ts: warning on large PRs (>500 lines), asserting CHANGELOG updates, checking PR descriptions for ticket references (JIRA-123), and posting structured sticky comments on GitHub PRs.

import { danger, warn, fail, message } from 'danger';

// 1. Check for CHANGELOG entries on feature branches
const hasChangelog = danger.git.modified_files.includes('CHANGELOG.md');
const isSourceCodeChange = danger.git.modified_files.some(f => f.startsWith('src/'));
if (isSourceCodeChange && !hasChangelog) {
  warn('Please add a summary of your changes to CHANGELOG.md.');
}

// 2. Warn when pull requests exceed reviewable size threshold
const bigPRThreshold = 500;
const linesChanged = (danger.github?.pr.additions ?? 0) + (danger.github?.pr.deletions ?? 0);
if (linesChanged > bigPRThreshold) {
  warn(`:warning: Big PR (${linesChanged} lines changed). Consider splitting this PR into smaller increments.`);
}

// 3. Assert PR body contains an issue tracker reference
const prBody = danger.github?.pr.body || '';
const issueRegex = /([A-Z]+-\d+|#\d+)/;
if (!issueRegex.test(prBody)) {
  fail('Please reference a ticket or issue key (e.g. CORE-123 or #45) in the PR description.');
}

name: Danger JS Review
on:
  pull_request:
    types: [opened, synchronize, reopened, edited]

jobs:
  danger:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
      contents: read
    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v3
        with:
          version: 9
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: 'pnpm'
      - run: pnpm install --frozen-lockfile
      - run: pnpm exec danger ci
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}