# React Router Code Review

> Reviews React Router code for proper data loading, mutations, error handling, and navigation patterns. Use when reviewing React Router v6.4+ code, loaders, actions, or navigation logic.

- Skill: `majiayu000/react-router-code-review-2` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/react-router-code-review-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/react-router-code-review-2/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/react-router-code-review-2

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# React Router Code Review

## Quick Reference

| Issue Type | Reference |
|------------|-----------|
| useEffect for data, missing loaders, params | [references/data-loading.md](references/data-loading.md) |
| Form vs useFetcher, action patterns | [references/mutations.md](references/mutations.md) |
| Missing error boundaries, errorElement | [references/error-handling.md](references/error-handling.md) |
| navigate() vs Link, pending states | [references/navigation.md](references/navigation.md) |

## 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?