App.js

import React, { useState, useEffect } from 'react';
import logo from './logo.svg';
import './App.css';

const App = () => {
  const [message, setMessage] = useState('...loading')

  useEffect(() => {
    async function fetchData () {
      try {
        let data = await (await fetch('/api')).json()
        setMessage(data.message)
      } catch (err) {
        setMessage(err.message)
      }
    }
    fetchData()
  })

  return (
    <div className="App">
      <header className="App-header">
        <img src={logo} className="App-logo" alt="logo" />
        <p>{message}</p>
        <p>Change me!</p>
        <p>
          Edited <code>src/App.js</code> and saved as a new branch.
        </p>
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer"
        >
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;