React TypeScript Development

Core Patterns

Component Structure

import { type FC, type ReactNode } from 'react';

interface ComponentProps {
  children?: ReactNode;
  variant?: 'primary' | 'secondary';
  disabled?: boolean;
  onClick?: () => void;
}

export const Component: FC<ComponentProps> = ({
  children,
  variant = 'primary',
  disabled = false,
  onClick,
}) => {
  return (
    <div 
      className={`component component--${variant}`}
      data-disabled={disabled}
      onClick={disabled ? undefined : onClick}
    >
      {children}
    </div>
  );
};

Typing Guidelines

Pattern	Use
FC<Props>	Standard functional components
ReactNode	Children, any renderable content
ComponentPropsWithoutRef<'button'>	Extend native HTML element props
forwardRef<HTMLDivElement, Props>	Components needing ref forwarding

Event Handler Types

onClick?: (event: React.MouseEvent<HTMLButtonElement>) => void;
onChange?: (event: React.ChangeEvent<HTMLInputElement>) => void;
onSubmit?: (event: React.FormEvent<HTMLFormElement>) => void;
onKeyDown?: (event: React.KeyboardEvent<HTMLInputElement>) => void;

Custom Hooks Pattern

import { useState, useCallback } from 'react';

interface UseToggleReturn {
  value: boolean;
  toggle: () => void;
  setTrue: () => void;
  setFalse: () => void;
}

export const useToggle = (initialValue = false): UseToggleReturn => {
  const [value, setValue] = useState(initialValue);
  
  const toggle = useCallback(() => setValue(v => !v), []);
  const setTrue = useCallback(() => setValue(true), []);
  const setFalse = useCallback(() => setValue(false), []);
  
  return { value, toggle, setTrue, setFalse };
};

Context Pattern

import { createContext, useContext, type FC, type ReactNode } from 'react';

interface ThemeContextValue {
  theme: 'light' | 'dark';
  toggleTheme: () => void;
}

const ThemeContext = createContext<ThemeContextValue | null>(null);

export const useTheme = (): ThemeContextValue => {
  const context = useContext(ThemeContext);
  if (!context) throw new Error('useTheme must be used within ThemeProvider');
  return context;
};

File Naming

ComponentName/
├── ComponentName.tsx          # Implementation
├── ComponentName.types.ts     # Types (optional)
├── ComponentName.stories.tsx  # Storybook
├── index.ts                   # Exports

Best Practices

1. Explicit return types for public functions
2. Discriminated unions for complex state
3. as const for literal types
4. Generic components for reusable patterns
5. Handle undefined explicitly

Integration

• Atomic Design: See atomic-design skill for hierarchy
• CSS Tokens: See css-tokens skill for styling
• Storybook: See storybook skill for docs