React Router Code Review

Quick Reference

Review Checklist

• Data loaded via loader not useEffect
• Route params accessed type-safely with validation
• Using defer() for parallel data fetching when appropriate
• Mutations use <Form> or useFetcher not manual fetch
• Actions handle both success and error cases
• Error boundaries with errorElement on routes
• Using isRouteErrorResponse() to check error types
• Navigation uses <Link> over navigate() where possible
• Pending states shown via useNavigation() or fetcher.state
• No navigation in render (only in effects or handlers)

When to Load References

• Reviewing data fetching code → data-loading.md
• Reviewing forms or mutations → mutations.md
• Reviewing error handling → error-handling.md
• Reviewing navigation logic → navigation.md

Review Questions

1. Is data loaded in loaders instead of effects?
2. Are mutations using Form/action patterns?
3. Are there error boundaries at appropriate route levels?
4. Is navigation declarative with Link components?
5. Are pending states properly handled?