TransformStream

const { readable, writable } = new TransformStream(transformer?: any, writableStrategy?: WritableStrategy);

readonly readable: ReadableStream;

readonly writable: WritableStream;

async function handleEnterRoom() {
  // Generate readable streams and writeable streams.
  const { readable, writable } = new TransformStream();
  // Fetch a remote resource. 
  const response = await fetch('https://www.tencentcloud.com/');
  // Respond to the client in streaming mode. 
  response.body.pipeTo(writable);

  return new Response(readable, response);
}

addEventListener('fetch', (event) => {
  event.respondWith(handleEvent(event));
});