合单APP支付

使用合单支付接口，用户只输入一次密码，即可完成多个订单的支付。目前最多一次可支持50笔订单进行合单支付。 官方文档

const { Formatter, Rsa } = require('wechatpay-axios-plugin')

wxpay.v3.combineTransactions.app.post({
  combine_appid,
  combine_mchid,
  combine_out_trade_no,
  scene_info,
  sub_orders,
  combine_payer_info,
  time_start,
  time_expire,
  notify_url,
  limit_pay,
  contract_info,
})
.then(({ data: { prepay_id: prepayid, contract_result, }, }) => {
  const noncestr = Formatter.nonce();
  const timestamp = '' + Formatter.timestamp();
  return { 
    appid,
    partnerid,
    prepayid,
    noncestr,
    timestamp,
    package: 'Sign=WXPay',
    sign: Rsa.sign(
      Formatter.joinedByLineFeed(appid, timestamp, noncestr, prepayid),
      merchantPrivateKeyInstance
    )
  }
})