chore(example-next-js): update example to chat room

[NathanFlurry]

No description provided.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
rivetkit-serverless	Error			Oct 16, 2025 7:40pm

[claude]

Claude finished @NathanFlurry's task —— View job

---

PR Review: Next.js Chat Room Example

This PR successfully converts the Next.js example from a simple counter to a real-time chat room, demonstrating RivetKit's capabilities for building stateful applications. Here's my comprehensive review:

Todo List:

• Read and analyze all changed files
• Review ChatRoom component implementation
• Examine CSS changes and styling approach
• Check Rivet registry modifications
• Assess code quality and best practices
• Identify potential bugs or security issues
• Evaluate performance considerations
• Provide comprehensive feedback

---

✅ Strengths

Code Quality & Architecture

• Clean component structure: Well-organized React component with proper separation of concerns
• Proper React patterns: Correct use of hooks, effects, and state management
• Type safety: Good TypeScript usage with proper typing for messages and state
• RivetKit integration: Excellent demonstration of actor patterns with state persistence

User Experience

• Responsive design: Mobile-friendly with collapsible sidebar
• Real-time functionality: Smooth message delivery and auto-scrolling
• Visual feedback: Connection status indicators and message timestamps
• Accessibility: Proper semantic HTML and keyboard navigation (Enter to send)

Styling & Design

• Modern dark theme: Professional Discord/Slack-like interface
• Smooth animations: Nice slide-in effects for new messages
• Custom scrollbars: Polished webkit scrollbar styling
• Avatar system: Color-coded user avatars with initials

⚠️ Issues & Recommendations

Security Concerns

1. XSS Vulnerability (High): examples/next-js/src/components/ChatRoom.tsx:188

   <div className="message-text">{msg.text}</div>

   • Issue: Raw message text rendering without sanitization
   • Risk: Malicious users could inject HTML/JavaScript
   • Fix: Use dangerouslySetInnerHTML with a sanitization library like DOMPurify, or implement text-only rendering

2. Input Validation (Medium): examples/next-js/src/rivet/registry.ts:13-20

   • Issue: No validation on sender name or message content
   • Risk: Empty messages, excessively long content, or malicious usernames
   • Fix: Add input validation and sanitization in the actor

Performance Considerations

1. Memory Growth (Medium): examples/next-js/src/rivet/registry.ts:8

   messages: [] as Message[],

   • Issue: Unlimited message history will cause memory growth
   • Fix: Implement message limit with cleanup of old messages

2. Re-renders (Low): examples/next-js/src/components/ChatRoom.tsx:164

   {messages.map((msg, i) => {

   • Issue: Using array index as key can cause unnecessary re-renders
   • Fix: Use message timestamp or add unique ID as key

Code Quality Issues

1. Error Handling (Medium): Missing error boundaries and network error handling

   • Fix: Add try-catch blocks around async operations and React error boundary

2. Accessibility (Low): examples/next-js/src/components/ChatRoom.tsx:204-211

   <input ... onKeyPress={handleKeyPress} />

   • Issue: onKeyPress is deprecated and may not work with assistive technologies
   • Fix: Use onKeyDown instead

3. Hardcoded Values: Magic numbers in CSS and component sizing

   • Fix: Extract to CSS custom properties or constants

Minor Improvements

1. State Management: Consider adding message loading states and retry mechanisms
2. Validation: Add client-side validation for username and room name formats
3. UX: Add typing indicators and message delivery confirmations
4. Performance: Implement virtual scrolling for large message lists

🧪 Test Coverage

• Missing: No tests included for the new chat functionality
• Recommendation: Add tests for:
  • Message sending and receiving
  • Connection state management
  • User interactions (room switching, username changes)
  • Error scenarios

📝 Documentation

The code is well-commented and follows RivetKit patterns. Consider adding JSDoc comments for the main ChatRoom component and utility functions.

🎯 Overall Assessment

This is a well-executed example that effectively demonstrates RivetKit's real-time capabilities. The main security concern with XSS should be addressed before merging, but overall the code quality is good and provides an excellent starting point for developers learning RivetKit.

Recommendation: Fix the XSS vulnerability and consider implementing message history limits before merging.

[NathanFlurry]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• chore(example-next-js): update example to chat room #1402 👈 (View in Graphite)
• fix(core): fix path for auto-configure serverless #1401
• chore(example-next-js): configure frontend #1400
• chore(core): update engine runner #1399
• fix(next-js): disable health check by defualt #1398
• chore(core): log headers with _RIVET_LOG_HEADERS #1397
• chore(example-next-js): improve deployment #1396
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• merge queue - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[graphite-app]

Merge activity

• Oct 16, 7:43 PM UTC: NathanFlurry added this pull request to the Graphite merge queue.
• Oct 16, 7:44 PM UTC: CI is running for this pull request on a draft pull request (#1403) due to your merge queue CI optimization settings.
• Oct 16, 7:44 PM UTC: Merged by the Graphite merge queue via draft PR: #1403.