【微信公众号】通过code换去openId和用户信息

[youmengme]

懒人福音，复制即用。

补充说明：获取code的scope需是snsapi_userinfo

import cloud from '@/cloud-sdk'
const appInfo = {
  appId: 'APP_ID',
  secret: 'APP_SECRET'
}
exports.main = async function (ctx: FunctionContext) {
  const { body } = ctx
  const { code } = body
  const { access_token, openid, refresh_token } = await codeToAccessToken(code) || {}
  if (!access_token) return null
  let token = access_token
  const isEffective = await checkAccessToken(token, openid)
  if (!isEffective) {
    const { access_token } = await refreshAccessToken(refresh_token) || {}
    token = access_token
  }

  const userInfo = await accessTokenToUserInfo(token, openid)
  return userInfo
}

function codeToAccessToken(code) {
  const url = `https://api.weixin.qq.com/sns/oauth2/access_token?appid=${appInfo.appId}&secret=${appInfo.secret}&code=${code}&grant_type=authorization_code`
  return cloud.fetch(url)
    .then((res) => Promise.resolve(res?.data?.access_token ? res.data : null))
    .catch(() => Promise.resolve(null))
}

function accessTokenToUserInfo(token: string, openId: string) {
  const url = `https://api.weixin.qq.com/sns/userinfo?access_token=${token}&openid=${openId}&lang=zh_CN`
  return cloud.fetch(url)
    .then((res) => Promise.resolve(res?.data?.nickname ? res.data : null))
    .catch(() => Promise.resolve(null))
}


function checkAccessToken(token: string, openId: string) {
  const url = `https://api.weixin.qq.com/sns/auth?access_token=${token}&openid=${openId}`
  return cloud.fetch(url)
    .then((res) => Promise.resolve(res?.data?.errcode === 0))
    .catch(() => Promise.resolve(false))
}


function refreshAccessToken(refreshToken: string) {
  const url = `https://api.weixin.qq.com/sns/oauth2/refresh_token?appid=${appInfo.appId}&grant_type=refresh_token&refresh_token=${refreshToken}`
  return cloud.fetch(url)
    .then((res) => Promise.resolve(res?.data?.nickname ? res.data : null))
    .catch(() => Promise.resolve(null))
}