react.mdc

---
description: React best practices and patterns for modern web applications
globs: **/*.tsx, **/*.jsx, components/**/*
---

# React Best Practices

## Component Structure
- Use functional components over class components
- Keep components small and focused
- Extract reusable logic into custom hooks
- Use composition over inheritance
- Implement proper prop types with TypeScript
- Split large components into smaller, focused ones

## Hooks
- Follow the Rules of Hooks
- Use custom hooks for reusable logic
- Keep hooks focused and simple
- Use appropriate dependency arrays in useEffect
- Implement cleanup in useEffect when needed
- Avoid nested hooks

## State Management
- Use useState for local component state
- Implement useReducer for complex state logic
- Use Context API for shared state
- Keep state as close to where it's used as possible
- Avoid prop drilling through proper state management
- Use state management libraries only when necessary

## Performance
- Implement proper memoization (useMemo, useCallback)
- Use React.memo for expensive components
- Avoid unnecessary re-renders
- Implement proper lazy loading
- Use proper key props in lists
- Profile and optimize render performance

## Forms
- Use controlled components for form inputs
- Implement proper form validation
- Handle form submission states properly
- Show appropriate loading and error states
- Use form libraries for complex forms
- Implement proper accessibility for forms

## Error Handling
- Implement Error Boundaries
- Handle async errors properly
- Show user-friendly error messages
- Implement proper fallback UI
- Log errors appropriately
- Handle edge cases gracefully

## Testing
- Write unit tests for components
- Implement integration tests for complex flows
- Use React Testing Library
- Test user interactions
- Test error scenarios
- Implement proper mock data

## Accessibility
- Use semantic HTML elements
- Implement proper ARIA attributes
- Ensure keyboard navigation
- Test with screen readers
- Handle focus management
- Provide proper alt text for images

## Code Organization
- Group related components together
- Use proper file naming conventions
- Implement proper directory structure
- Keep styles close to components
- Use proper imports/exports
- Document complex component logic