## React Best Practices

### Component Structure

```typescript
// ✅ GOOD: Functional component with types
interface ButtonProps {
  children: React.ReactNode
  onClick: () => void
  disabled?: boolean
  variant?: 'primary' | 'secondary'
}

export function Button({
  children,
  onClick,
  disabled = false,
  variant = 'primary'
}: ButtonProps) {
  return (
    <button
      onClick={onClick}
      disabled={disabled}
      className={`btn btn-${variant}`}
    >
      {children}
    </button>
  )
}

// ❌ BAD: No types, unclear structure
export function Button(props) {
  return <button onClick={props.onClick}>{props.children}</button>
}
```

### Custom Hooks

```typescript
// ✅ GOOD: Reusable custom hook
export function useDebounce<T>(value: T, delay: number): T {
  const [debouncedValue, setDebouncedValue] = useState<T>(value)

  useEffect(() => {
    const handler = setTimeout(() => {
      setDebouncedValue(value)
    }, delay)

    return () => clearTimeout(handler)
  }, [value, delay])

  return debouncedValue
}

// Usage
const debouncedQuery = useDebounce(searchQuery, 500)
```

### State Management

```typescript
// ✅ GOOD: Proper state updates
const [count, setCount] = useState(0)

// Functional update for state based on previous state
setCount(prev => prev + 1)

// ❌ BAD: Direct state reference
setCount(count + 1)  // Can be stale in async scenarios
```

### Conditional Rendering

```typescript
// ✅ GOOD: Clear conditional rendering
{isLoading && <Spinner />}
{error && <ErrorMessage error={error} />}
{data && <DataDisplay data={data} />}

// ❌ BAD: Ternary hell
{isLoading ? <Spinner /> : error ? <ErrorMessage error={error} /> : data ? <DataDisplay data={data} /> : null}
```