如何从 Node.js 中的 Http.IncomingMessage 检测 http 与 https

给定一个Http.IncomingMessage由一个创建http(s).Server为了响应请求，检测请求是否是 http 与 https 的正确/推荐方法是什么？

一些我不知道的随机想法是否正确

• 检查端口

  // seems wrong - might be using a different port
  const isHTTPS = req.socket.address().port === 443;
  

• 检查套接字是否有证书

  // does no cert mean it wasn't https?
  const isHTTPS = req.socket.getPeerCertificate &&
       request.socket.getPeerCertificate() !== null;
  

• 检查socket是否有该功能getPeerCertificate

  // does no func = !https?
  const isHTTPS = req.socket.getPeerCertificate !== undefined;
  

• 检查套接字是否是tls.TLSSocket

  const tls = require('tls');
  
  const isHTTPS = req.socket instanceof tls.TLSSocket;
  

• other?

req.socket将有一个名为encrypted https://nodejs.org/api/tls.html#tls_tlssocket_encrypted set to true用于 HTTPS 连接。