React SSR完全ガイド1：基本の流れとReact 18のストリーミング

import express from 'express';
import React from 'react';
import { renderToPipeableStream } from 'react-dom/server';
import App from './App';
const app = express();
app.get('*', (req, res) => {
  const { pipe } = renderToPipeableStream(<App />, {
    onShellReady() {
      res.setHeader('Content-Type', 'text/html');
      pipe(res);
    },
    onError(err) {
      console.error(err);
    }
  });
});

function App() {
  return (
    <div>
      <Header />
      <Suspense fallback={<div>Loading content...</div>}>
        <MainContent />
      </Suspense>
      <Footer />
    </div>
  );
}