开发者工具v1.03 2005140， node8.9，基础库2.2.5， 云函数代码中 import waterfall from 'aysnc/waterfall' 后本地调试只能加载左面的云函数列表，中间调试窗口和右边子窗口都空白无发硬。 注释掉import语句后调试器正常，但是报一个奇怪的语法错误， 说希望执行一个函数，实际上waterfall已经执行了。 上传图片总是失败，      [error] Uncaught Exception:  Error: expected a function     at wrapAsync (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:198:50)     at nextTask (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:4575:24)     at Object.waterfall (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:4587:9)     at Object.awaitable [as waterfall] (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:208:32)     at E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\index.js:141:17     at E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:2154:44     at replenish (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:440:21)     at E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:445:13     at eachLimit$1 (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:2243:34)     at awaitable (E:\wx\projs\wxminiProgCloud\cloudfunctions\ftpOper\node_modules\async\dist\async.js:208:32) 以下是waterfall函数的输出 query: /E:/wx/projs/wxminiProgCloud/cloudfunctions/ftpOper/index.js:85 db get err: TypeError: Cannot read property 'getTime' of undefined /E:/wx/projs/wxminiProgCloud/cloudfunctions/ftpOper/index.js:28 save file cmp: [object Object] /E:/wx/projs/wxminiProgCloud/cloudfunctions/ftpOper/index.js:18 mycallback index.js:170 ftp connection had end index.js:165 ftp connection had closed with err: false 代码如下，      let i = 0       ipCamMapArr = new Array()       ipCamMap.forEach(function(key){         ipCamMapArr[i] = {ip: key, filetime: ipCamMap.get(key)}         i++       })       function cb(){console.log('cb,cb')}       async.eachSeries(ipCamMapArr,         function(item, cb){           async.waterfall(             [             ftpGetPicFile(item, mycallback),             savePicFile(item, mycallback),             //checkPicFile(item, cb2),             updateRec(item, mycallback)           ],           function(err, result){             console.log('waterfall cb: ' + err + ', res: ' + result)           }           )           cb()         },         function(err, result){           console.log('eachofser cb: ' + err + ', res: ' + result)         }       )

云函数使用websocket client连接第三方服务器获取数据并返回给用户小程序端，websocket保持久性，云函数怎样获取websocket上的各种事件如open，error，onmessage（多次），close等并通知用户小程序端知晓。