インモビインモビ

import { useState, useEffect } from "react";
import axios from "axios";

axios.defaults.withCredentials = true;

function App() {
  const [user, setUser] = useState(null);
  const [form, setForm] = useState({ username: "", password: "" });

  const fetchUser = async () => {
    try {
      const res = await axios.get("http://localhost:4000/me");
      setUser(res.data.user);
    } catch {
      setUser(null);
    }
  };

  useEffect(() => {
    fetchUser();
  }, []);

  const login = async () => {
    try {
      await axios.post("http://localhost:4000/login", form);
      fetchUser();
    } catch {
      alert("ログイン失敗");
    }
  };

  const logout = async () => {
    await axios.post("http://localhost:4000/logout");
    setUser(null);
  };

  return (
    div style={{ margin: 20 }}>
      h2>セッション認証デモ/h2>
      {user ? (
        
          p>ようこそ、{user.username}さん！/p>
          button onClick={logout}>ログアウト/button>
        />
      ) : (
        
          input  style={{ marginRight: 20 }}
            placeholder="username"
            onChange={(e) => setForm({ ...form, username: e.target.value })}
          />
          input style={{ marginRight: 20 }}
            placeholder="password"
            type="password"
            onChange={(e) => setForm({ ...form, password: e.target.value })}
          />
          button onClick={login}>ログイン/button>
        />
      )}
    /div>
  );
}

export default App;