TypeScript Best Practices for React Applications

TypeScript has become the standard for modern React development, offering powerful type safety and enhanced developer experience. Let's explore the best practices that will elevate your React applications.

Component Typing Strategies

Props Interface Definition

Always define clear interfaces for your component props. This provides autocomplete, catches errors at compile-time, and serves as documentation for other developers.

interface ButtonProps {
  variant: 'primary' | 'secondary' | 'ghost';
  size?: 'sm' | 'md' | 'lg';
  children: React.ReactNode;
  onClick?: () => void;
  disabled?: boolean;
}

export const Button: React.FC<ButtonProps> = ({
  variant,
  size = 'md',
  children,
  onClick,
  disabled = false
}) => {
  return (
    <button
      className={`btn btn-${variant} btn-${size}`}
      onClick={onClick}
      disabled={disabled}
    >
      {children}
    </button>
  );
};

Advanced Patterns

Generic Components

Create reusable components with generics to work with different data types while maintaining full type safety.

interface ListProps<T> {
  items: T[];
  renderItem: (item: T) => React.ReactNode;
  keyExtractor: (item: T) => string;
}

function List<T>({ items, renderItem, keyExtractor }: ListProps<T>) {
  return (
    <ul>
      {items.map((item) => (
        <li key={keyExtractor(item)}>
          {renderItem(item)}
        </li>
      ))}
    </ul>
  );
}

This pattern allows you to create a single List component that works with any data type, providing type-safe callbacks and key extraction.

Key Takeaways

• Always define explicit interfaces for component props
• Use discriminated unions for variant-based components
• Leverage generics for reusable, type-safe components
• Let TypeScript infer types when possible to reduce verbosity
• Use strict mode to catch potential issues early

These patterns will significantly improve your code quality and development experience! Start implementing them in your next React project to see the benefits of proper TypeScript usage.