Question

我写了一个node.js模块。我的模块有一个isValid方法，它使用给定标记作为查找值从数据库中读取数据。如果数据有效，则调用setData方法，如果数据有效则返回true，否则返回false。

基于我记录到控制台的一些消息，该函数应该返回true但是当我执行`if ... else ...``check时，它总是返回false。

这是我的模块

var db = require('./dbconnect');

var PHPUnserialize = require('php-unserialize');


function validator (){
  this.icws = null;
};


/**
* @setData
*
* Set the value of the icwsData
*
* @return void
*/
validator.prototype.setData = function (icws){
  this.icws = icws;
};


/**
* @getData
*
* Get the value of the icwsData
*
* @return object
*/
validator.prototype.getData = function (){
  return this.icws;
};


/**
* @isValid
*
* Checks if a token is valid or not
*
* @params (string) tokenId: the PHP sessionId
* @params (string) myIP: the user IP address
* @params (integer) duration: the duration to keep the session good for in microseconds
*
* @return bool
*/
validator.prototype.isValid = function (tokenId, myIP, duration){

  if(!tokenId || !myIP){
    console.log('Missing TokenID or IP Address');
    return false;
  }

  if(!duration){
    duration = 3600;
  }

  var self = this;
  db.sqlConnection('SELECT ' +
                   '  su.icws_username AS username ' +
                   ', su.icws_password AS password ' +
                   ', su.icws_workstation AS workstation ' +
                   ', icws.host ' +
                   ', icws.port ' +
                   ', s.data ' +
                   'FROM sessions AS s ' +
                   'INNER JOIN view_users AS su ON su.user_id = s.user_id ' +
                   'INNER JOIN icws_servers AS icws ON icws.server_id = su.icws_server_id ' +
                   'WHERE s.session_id = ? '
                   , [tokenId] , function(err, rows){


    if(err){ 
      console.log(err);
      return false;
    }

    if(!rows[0] || !rows[0].data){
      console.log('No match found for this token!');
      return true;
    }

    var data = PHPUnserialize.unserializeSession(rows[0].data);
    var now = Math.floor(new Date() / 1000);

    if(!data.MA_IDLE_TIMEOUT || (data.MA_IDLE_TIMEOUT + duration) < now){
      console.log('The session Times out!');
      return false;
    }

    if(!data.MA_IP_ADDRESS || myIP != data.MA_IP_ADDRESS){
      console.log('This session have been hijacked!');
      return false;
    }

    self.setData(rows[0]);
    console.log('Good - return true!');
    return true;
  });

};


module.exports = validator;

以下是我如何调用模块

var sessionValidator = require('./modules/validator.js');
var sessionChecker = new sessionValidator();
var boo = sessionChecker.isValid(decodedToken, myIP, env.session.duration);
if(boo){
    console.log('Worked!');
} else {
    console.log('No Go!');
}

return;

控制台打印

Good - return true!
No Go!

我期待这个输出

Good - return true!
Worked!

为什么这个函数总是返回false？

如果您需要查看我的dbconnect模块，请参阅以下代码

// Dependencies
var mysql   = require('mysql'),
    env  = require('./config');

/**
 * @sqlConnection
* Creates the connection, makes the query and close it to avoid concurrency conflicts.
*
* @param (string) sql: the sql query
* @param (array) values: contains values to sanitize for the query
* @param (function) next: call back function that will have data set if a select query is passed
*
* @return void
*/  

exports.sqlConnection = function (sql, values, next) {

    // It means that the values hasnt been passed
    if (arguments.length === 2) {
        next = values;
        values = null;
    }

    var connection = mysql.createConnection({
          host: env.mysql.host,
          user: env.mysql.user,
          password: env.mysql.password,
          database: env.mysql.database
    });

    connection.connect(function(err) {
        if (err !== null) {
            console.log("[MYSQL] Error connecting to mysql:" + err );
        }
    });

    connection.query(sql, values, function(err) {

        connection.end(); // close the connection

        if (err) {
            throw err;
        }

        // Execute the callback
        next.apply(this, arguments);
    });
}

EDITED

当前输出实际上是

No Go!
Good - return true!

Answer 1

数据库访问本身是异步的。

实际发生的是isValid返回undefined（假，但没有明确false），因此条件表示无效。

使用===并检查类型以及真实/虚假通常是有意义的：它可能有助于说明代码没有达到预期的原因/位置。

如评论中所示，使用回调或承诺是规范的方法。

Javascript函数返回false，它应该返回true

1 个答案: