React Component Refactoring

React Component Refactoring — Safe Large Component Splitting

Refactor large React components (>500 lines) into smaller, maintainable pieces without breaking functionality. This skill captures patterns observed between CZA (3331 lines across 4 components) and WAI (965 lines) implementations.

When to Use

Use this skill when:

• A React component exceeds 400-500 lines
• Component contains multiple distinct UI sections or logical concerns
• Code becomes difficult to test or maintain
• You need to follow WAI-style modular architecture

Refactoring Patterns

1. UI Component Isolation (Highest Priority)

Extract reusable UI components from the main component:

// BEFORE: Inline components in main file
const NavIcon: React.FC<NavIconProps> = ({ active, icon: Icon, onClick, label }) => (
  <button className={`...`}>
    <Icon className="h-5 w-5" />
    <span className="...">{label}</span>
  </button>
);

// AFTER: Separate component file
export interface NavIconProps {
  active: boolean;
  icon: LucideIcon;
  onClick: () => void;
  label: string;
  accentColor?: string;
}

export const NavIcon: React.FC<NavIconProps> = ({ active, icon: Icon, onClick, label, accentColor }) => (
  <button className={`...`}>
    <Icon className="h-5 w-5" />
    <span className="...">{label}</span>
  </button>
);

Safety Check: Verify all props are properly exported and imported

2. Hook Extraction (Logic Separation)

Move complex logic and state management into custom hooks:

// BEFORE: Logic inline in component
const [conversations, setConversations] = useState<Conversation[]>([]);
const [loading, setLoading] = useState(true);

useEffect(() => {
  fetchConversations();
}, []);

// AFTER: Custom hook
const useConversations = () => {
  const [conversations, setConversations] = useState<Conversation[]>([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    fetchConversations();
  }, []);

  return { conversations, loading };
};

3. Repository Pattern (WAI Style)

Extract data access logic into repository files:

// lib/repositories/conversationRepository.ts
export const conversationRepository = {
  fetchAll: async (): Promise<Conversation[]> => {
    // Supabase/API calls here
  },
  updateStatus: async (conversationId: string, status: string) => {
    // Update logic
  }
};

4. Lazy Loading Pattern

Use React.lazy() for code splitting:

const LazyAnalytics = lazy(() => import('./AnalyticsView'));
const LazyChatView = lazy(() => import('./ChatView'));

Safety Protocol

Pre-Refactor Checklist

1. ✅ Run existing tests: npm test
2. ✅ Build verification: npm run build
3. ✅ Create backup: git commit -am "pre-refactor backup"
4. ✅ Verify live site functionality

Post-Refactor Verification

1. ✅ TypeScript compilation: npx tsc --noEmit
2. ✅ Build success: npm run build
3. ✅ Tests pass: npm test
4. ✅ Live deploy check (Netlify/Vercel)
5. ✅ Manual smoke test critical flows

Risk Mitigation

• Never refactor without tests
• Always verify build before pushing
• Preserve all existing props and interfaces
• Maintain backward compatibility
• Test each extracted component individually

WAI vs CZA Comparison Patterns

Common Pitfalls & Fixes

Pitfall: Missing Default Export

// ❌ Missing export
export default Dashboard;

Pitfall: Prop Interface Mismatch

// ✅ Ensure all optional props are marked with ?
export interface NavIconProps {
  active: boolean;
  icon: LucideIcon;
  onClick: () => void;
  label: string;
  accentColor?: string;  // Optional prop
}

Pitfall: CSS Class Consistency

// ✅ Preserve all existing class names exactly
className="flex flex-col items-center justify-center gap-1 min-w-[64px] py-2 px-3 rounded-xl transition-all active:scale-95 select-none touch-manipulation"

Implementation Workflow

1. Analyze: Identify logical component boundaries
2. Extract UI: Move reusable components to separate files
3. Create Hooks: Extract complex logic into custom hooks
4. Add Repositories: Move data access to repository files
5. Verify: Run full test/build/deploy cycle
6. Commit: Small, focused commits for each extraction

Adopted from successful WAI patterns: Dashboard.tsx (377 lines), ChatView.tsx (209 lines), AnalyticsView.tsx (299 lines), SettingsView.tsx (80 lines).