Advanced React Development

Chapter 14: React Best Practices

14.1 Code Quality

Following best practices ensures maintainable, performant, and bug-free React applications.

Component Best Practices:

• Keep components small and focused (single responsibility)
• Use descriptive component and prop names
• Extract reusable logic into custom hooks
• Use TypeScript for type safety
• Write self-documenting code with clear structure

// Good: Small, focused component
function UserAvatar({ user, size = 'medium' }) {
    return (
        <img
            src={user.avatar}
            alt={user.name}
            className={`avatar avatar-${size}`}
        />
    );
}

// Bad: Component doing too much
function UserProfile({ user }) {
    // Fetching, formatting, rendering all in one
}

14.2 Performance Best Practices

• Use React.memo for expensive components
• Memoize callbacks with useCallback
• Memoize expensive computations with useMemo
• Lazy load routes and heavy components
• Virtualize long lists
• Optimize images and assets

14.3 State Management Best Practices

• Keep state as local as possible
• Lift state up only when necessary
• Use appropriate state management solution
• Avoid prop drilling with Context or state management
• Normalize complex state structures

14.4 Testing Best Practices

• Test user behavior, not implementation
• Use React Testing Library
• Write integration tests for critical flows
• Mock external dependencies
• Maintain good test coverage