blake-john/agent-config/react-expert

// app/users/page.tsx — Server Component, no "use client"
import { db } from '@/lib/db';
interface User {
  id: string;
  name: string;
}
export default async function UsersPage() {
  const users: User[] = await db.user.findMany();
  return (
    <ul>
      {users.map((user) => (
        <li key={user.id}>{user.name}</li>
      ))}
    </ul>
  );
}

'use client';
import { useActionState } from 'react';
async function submitForm(_prev: string, formData: FormData): Promise<string> {
  const name = formData.get('name') as string;
  // perform server action or fetch
  return `Hello, ${name}!`;
}
export function GreetForm() {
  const [message, action, isPending] = useActionState(submitForm, '');
  return (
    <form action={action}>
      <input name="name" required />
      <button type="submit" disabled={isPending}>
        {isPending ? 'Submitting…' : 'Submit'}
      </button>
      {message && <p>{message}</p>}
    </form>
  );
}

import { useState, useEffect } from 'react';
function useWindowWidth(): number {
  const [width, setWidth] = useState(() => window.innerWidth);
  useEffect(() => {
    const handler = () => setWidth(window.innerWidth);
    window.addEventListener('resize', handler);
    return () => window.removeEventListener('resize', handler); // cleanup
  }, []);
  return width;
}