承諾在解決之前轉到下一個.then（）？

Question

我有一個簡單的Web應用程序，它登錄到我面向客戶的Web服務器並在獲取請求上下載日誌文件。當您向特定路由發送獲取請求時，模塊將啓動通過sftp連接到Web服務器並在本地下載日誌的2個獨立服務器。出於某種原因，我的鏈中的last then（）方法在promise解決之前觸發。

router.js：

var express = require('express'); 
var router = express.Router(); 
var gather = require('../api/gather'); 
/* GET home page. */ 
router.get('/', function(req, res, next) { 
    res.render('home'); 
}); 
router.get('/api/gather',function(req,res,next){ 
    console.log('sending web9 target'); 
    gather.logs(['WEB9']) 
    .then((logsFound)=>{ 
     console.log('sending web 11 target'); 
     gather.logs(['WEB11',logsFound]) 
    }) 
    .then((logsFound)=>{ 
    console.log(logsFound); 
    console.log('downloading finished rendering home with message'); 
    res.render('home',{message: logsFound+' Log Files Ready for Pickup'}); 
    }) 
    .catch((e)=>{ 
    res.render('home',{message: e}); 
    }); 

}); 
module.exports = router; 

/api/gather.js

//require ftp modules and define client 
let Client = require('ssh2-sftp-client'); 
let sftp = new Client(); 
var fs = require('fs'); 
let sftp2 = new Client(); 
//set server configs 
var boomeConfig = { 
    host: process.env.FTP_HOST, 
    port: process.env.FTP_PORT, 
    username: process.env.FTP_USER, 
    password: process.env.FTP_PASS 
}; 
var webServerConfig = { 
    port: process.env.WEB_PORT, 
    username: process.env.WEB_USER, 
    password: process.env.WEB_PASS 
}; 
let message; 
const logDir = '/opt/foobar/logs/'; 
module.exports.logs = function(req, res){ 
    console.log('hit gather module'); 
    const target = req[0]; 
    let logsFound = req[1] || 0; 
    return new Promise((resolve,reject)=>{ 
      if(target === 'WEB9'){ 
       webServerConfig.host = process.env.WEB9_HOST; 
      }else if(target === 'WEB11'){ 
       webServerConfig.host = process.env.WEB11_HOST;  
      }else{ 
       message = 'No Server Target Found'; 
       resolve(message); 
      }  
      sftp.connect(webServerConfig) 
      .then(()=>{ 
       return sftp.list(logDir); 
      }) 
      .then((data)=>{ 
       for(var i = 0; i < data.length; i++){ 
        const remoteFileName = logDir + data[i].name; 
        const localFileName = './downloads/'+target+'/' + data[i].name; 
        //console.log('saving file '+localFileName); 
        sftp.get(remoteFileName).then((stream) => { 
         stream.pipe(fs.createWriteStream(localFileName)); 
        }); 
       } 
       console.log('Found '+data.length+' Logs on '+target); 
       sftp.end(); 
       logsFound += data.length; 
       console.log('Got '+target+' Files Moving to next'); 
       if(target ==='WEB11'){ 
        console.log('Total count '+logsFound); 
       } 
      }).then((logsFound)=>{ 
       resolve(logsFound); 
      }) 
      .catch((e)=>{ 
       console.log('error: '+e); 
       reject(e);  
      }); 
    })  
} 

我家的路是越來越有logsFound呈現爲未定義。

我能想到的唯一的事情是，它可以在

sftp.get(remoteFileName).then((stream) => { 
         stream.pipe(fs.createWriteStream(localFileName)); 
        }); 

仍然流文件時承諾解決。

Answer 1

問題是我解決了我的承諾，但我的路線寫的方式我創建了Promise構造函數反模式。由於BERGI和Kevin B.

編輯路線

var express = require('express'); 
    var router = express.Router(); 
    var gather = require('../api/gather'); 
    /* GET home page. */ 
    router.get('/', function(req, res, next) { 
     res.render('home'); 
    }); 
    router.get('/api/gather',function(req,res,next){ 
     console.log('sending web9 target'); 
     return gather.logs(['WEB9']) 
     .then((logsFound)=>{ 
      console.log('sending web 11 target'); 
      return gather.logs(['WEB11',logsFound]) 
     }) 
     .then((logsFound)=>{ 
     console.log(logsFound); 
     console.log('downloading finished rendering home with message'); 
     res.render('home',{message: logsFound+' Log Files Ready for Pickup'}); 
     }) 
     .catch((e)=>{ 
     res.render('home',{message: e}); 
     }); 

    }); 
    module.exports = router;