async function sendToServer(url: URL): Promise<Response> {
  if (url.href.includes('/_favicon/')) {
    const response = await fetch(url.href)
    return new Response(response.body, {
      headers: {
        'Content-Type': response.headers.get('Content-Type') ?? 'text/javascript',
      },
   })
  }

  // change the url to point to the dev server
  url.protocol = 'http:'
  url.host = 'localhost'
  url.port = __SERVER_PORT__
  // add a timestamp to force Chrome to do a new request
  url.searchParams.set('t', Date.now().toString())
  // URLSearchParams adds "=" to every empty param & vite doesn't like it
  const response = await fetch(url.href.replace(/=$|=(?=&)/g, ''))
  // circumvent extension CSP by creating response from extension origin
  return new Response(response.body, {
    headers: {
      'Content-Type': response.headers.get('Content-Type') ?? 'text/javascript',
    },
  })
}