React19

React Best Practices

Component Design & Structure

• Prefer functional components with Hooks over class components.
• Keep components small, focused, and reusable.
• Use composition to combine components. Avoid inheritance patterns.
• Define prop types clearly (using TypeScript interfaces/types is recommended).
• Split large components into smaller, more manageable ones.
• Colocate related components, hooks, and types where appropriate.

Hooks

• Strictly follow the Rules of Hooks (only call hooks at the top level, only from React functions).
• Extract reusable stateful logic into custom Hooks.
• Keep custom Hooks focused on a single concern.
• Provide exhaustive and correct dependency arrays for useEffect, useCallback, and useMemo.
• Implement cleanup logic in useEffect for subscriptions, timers, or other resources that need disposal.

State Management

• Use useState for simple, local component state.
• Use useReducer for more complex state logic involving multiple sub-values or state transitions.
• Use React Context API (useContext) for sharing state that needs to be accessible by many components at different levels, but be mindful of performance implications.
• Keep state as close as possible to where it's needed.
• Avoid excessive prop drilling by lifting state up or using Context/state management solutions.
• Evaluate the need for external state management libraries carefully; often, built-in hooks and composition suffice.

Performance Optimization

• Avoid unnecessary re-renders:
  • Use React.memo to memoize components based on prop equality.
  • Use useCallback to memoize callback functions passed to optimized child components.
  • Use useMemo to memoize expensive calculations.
• Apply memoization judiciously; profile first to identify actual bottlenecks.
• Use proper key props when rendering lists to help React identify items.
• Use code splitting (e.g., React.lazy with Suspense) to lazy-load components not needed immediately.
• Profile component render performance using React DevTools.