fetch

• https://developer.mozilla.org/en-US/docs/Web/API/fetch
• 禁止修改的 Header
  • Proxy-*
  • Sec-*
  • Accept-
  • Access-Control-
  • Cookie
  • Content-Length
  • Date
  • DNT
  • Expect
  • Host
  • Keep-Alive
  • Origin
  • Referer
  • Transfer-Encoding
  • Upgrade
  • Via

credentials

请求是否带 Cookie

• omit
• same-origin - 默认
• include - 总是包含

preflight 不会包含。