# 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 

---
description: TypeScript coding standards and best practices for modern web development
globs: **/*.ts, **/*.tsx, **/*.d.ts
---

# TypeScript Best Practices

## Type System
- Prefer interfaces over types for object definitions
- Use type for unions, intersections, and mapped types
- Avoid using `any`, prefer `unknown` for unknown types
- Use strict TypeScript configuration
- Leverage TypeScript's built-in utility types
- Use generics for reusable type patterns

## Naming Conventions
- Use PascalCase for type names and interfaces
- Use camelCase for variables and functions
- Use UPPER_CASE for constants
- Use descriptive names with auxiliary verbs (e.g., isLoading, hasError)
- Prefix interfaces for React props with 'Props' (e.g., ButtonProps)

## Code Organization
- Keep type definitions close to where they're used
- Export types and interfaces from dedicated type files when shared
- Use barrel exports (index.ts) for organizing exports
- Place shared types in a `types` directory
- Co-locate component props with their components

## Functions
- Use explicit return types for public functions
- Use arrow functions for callbacks and methods
- Implement proper error handling with custom error types
- Use function overloads for complex type scenarios
- Prefer async/await over Promises

## Best Practices
- Enable strict mode in tsconfig.json
- Use readonly for immutable properties
- Leverage discriminated unions for type safety
- Use type guards for runtime type checking
- Implement proper null checking
- Avoid type assertions unless necessary

## Error Handling
- Create custom error types for domain-specific errors
- Use Result types for operations that can fail
- Implement proper error boundaries
- Use try-catch blocks with typed catch clauses
- Handle Promise rejections properly

## Patterns
- Use the Builder pattern for complex object creation
- Implement the Repository pattern for data access
- Use the Factory pattern for object creation
- Leverage dependency injection
- Use the Module pattern for encapsulation