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Ending imap-simple connection within recursion

I currently have a script that checks for an incoming email (in a mailbox) every 30 seconds, using a recursion.
The package I'm using for this testing is imap-simple.
The below script currently does this as required;
var imaps = require('imap-simple');
const { connect } = require('net');
var config = {
imap: {
user: 'qatestspecialist#outlook.com',
password: 'specialistQa',
host: 'imap-mail.outlook.com',
port: 993,
tls: true,
authTimeout: 30000
}
};
module.exports = {
'delete any existing emails...': function () {
imaps.connect(config).then(function (connection) {
connection.openBox('INBOX').then(function () {
var searchCriteria = ['ALL'];
var fetchOptions = { bodies: ['TEXT'], struct: true };
return connection.search(searchCriteria, fetchOptions);
//Loop over each message
}).then(function (messages) {
let taskList = messages.map(function (message) {
return new Promise((res, rej) => {
var parts = imaps.getParts(message.attributes.struct);
parts.map(function (part) {
return connection.getPartData(message, part)
.then(function (partData) {
//Display e-mail body
if (part.disposition == null && part.encoding != "base64"){
console.log(partData);
}
//Mark message for deletion
connection.addFlags(message.attributes.uid, "\Deleted", (err) => {
if (err){
console.log('Problem marking message for deletion');
rej(err);
}
res(); //Final resolve
});
});
});
});
});
return Promise.all(taskList).then(() => {
connection.imap.closeBox(true, (err) => { //Pass in false to avoid delete-flagged messages being removed
if (err){
console.log(err);
}
});
connection.end();
});
});
});
},
'send email to seller and wait for mailbox notification': function (browser) {
// script to send an email to the mailbox...
},
'get new email info': function(browser) {
const createPromise = ms => new Promise((resolve, reject) => {
setTimeout(() => resolve(ms), ms)
});
function findUnseenEmails(connection) {
return connection.openBox('INBOX').then(function () {
var searchCriteria = ['UNSEEN'];
var fetchOptions = {
bodies: ['HEADER', 'TEXT'],
markSeen: false
};
return connection.search(searchCriteria, fetchOptions).then(function (results) {
var subjects = results.map(function (res) {
return res.parts.filter(function (part) {
return part.which === 'HEADER';
})
[0].body.subject[0];
});
return subjects.length > 0 ? subjects : createPromise(30000).then(function() { return findUnseenEmails(connection);
});
});
});
}
imaps.connect(config).then(function (connection) {
return findUnseenEmails(connection)
})
.then((subjects) => console.log(JSON.stringify(subjects)));
},
'Closing the browser': function (browser) {
browser.browserEnd();
}
};
This waits for an email and then displays the email 'header'.
However, the imap connection does not close, and stays open which is stopping my test suite from completing as the associated test never actually finishes.
I've tried adding the imap-simple command connection.end() in several places after the
imaps.connect(config).then(function (connection) {
return findUnseenEmails(connection)
})
part of the script, but it doesn't work.
So I'm just wondering if anyone knows where I should be adding this connection.end() command in order for the connection to be closed once an email has been received?
Any help would be greatly appreciated.

This has now been resolved in another post, using the following;
if (subjects.length > 0) {
connection.end();
return subjects;
} else {
return createPromise(5000).then(function() { return findUnseenEmails(connection)});
}

Express dosn't get return of other function querying Mongodb [duplicate]

This question already has answers here:
How do I return the response from an asynchronous call?
(41 answers)
Closed 3 years ago.
I'm working in a simple API Key authentication, I just want to verify the given key against the user provied key.
I have a seperate file with the function querying the database, and returning true/false and the user object.
But in my route.js file, the return object is undefined even tough in my auth.js file it isn't.
I tried making the the function in router.get an async function using express-promise-router and making the function an await return var user = await auth.verify(req.params.uid, req.get("token")) but I don't realy know how async works.
router.js
[...]
router.get('/list/:uid', function(req, res) {
var user = auth.verify(req.params.uid, req.get("token"))
console.log("User: " + user) // <-- Undefined
if (user.status) {
res.send("Success")
} else {
res.status(403)
res.json({status: 403, error: "Unkown User / Token"})
}
})
[...]
auth.js
var db = require('./db')
var ObjectId = require('mongodb').ObjectId;
module.exports = {
verify: (uid, key) => {
try {
var collection = db.get().collection('users')
const obj_id = new ObjectId(uid)
const query = { _id: obj_id }
collection.find(query).limit(1).toArray(function(err, user) {
var status = 0;
var usr = {};
if (err) {throw err}else{status=1}
if (user.length <= 0) {throw "NotExistingExc"; status = 0}else{
usr = user[0];
if (key != usr.api) status = 0
}
var returnObj = {
status: status,
user: usr
} /* --> Is {
status: 1,
user: {
_id: d47a2b30b3d2770606942bf0,
name: 'Sh4dow',
groups: [ 0 ],
api: 'YWFiMDI1MGE4NjAyZTg0MWE3N2U0M2I1NzEzZGE1YjE='
}
}
*/
return returnObj;
})
} catch (e) {
console.error(e)
return {
status: 0,
user: {},
error: e
}
}
}
}
db.js (Idk if needed)
var MongoClient = require('mongodb').MongoClient
var state = {
db: null,
}
exports.connect = function(url, done) {
if (state.db) return done()
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
if (err) return done(err)
state.db = db
done()
})
}
exports.get = function() {
return state.db.db("database")
}
exports.close = function(done) {
if (state.db) {
state.db.close(function(err, result) {
state.db = null
state.mode = null
done(err)
})
}
}
I want to have the returnObjin auth.js in the router.get of my route.js file.

Make auth.verify return a Promise which we can then await for it inside router, You can just make the callback async no need for express-promise-router
router.get('/list/:uid', async function(req, res) {
try {
var user = await auth.verify(req.params.uid, req.get("token"))
console.log("User: " + user)
if (user.status) {
res.send("Success")
} else {
res.status(403).json({status: 403, error: "Unkown User / Token"})
}
} catch (e) {
console.error(e)
res.status(/* */).json(/* */)
}
})
auth
module.exports = {
verify: (uid, key) => new Promise((resolve, reject) => {
var collection = db.get().collection('users')
const obj_id = new ObjectId(uid)
const query = { _id: obj_id }
collection.find(query).limit(1).toArray(function(err, user) {
var status = 0;
var usr = {};
if (err) {
reject(err)
return
} else {
status = 1
}
if (user.length <= 0) {
reject(new Error("NotExistingExc"))
return
} else {
usr = user[0]
if (key != usr.api) status = 0
}
var returnObj = {
status: status,
user: usr
}
resolve(returnObj);
})
}
}

In short, the reason you get undefined is because the code in auth.js is asyncronous. But you're really close. The toArray method in MongoDB returns a promise, so you need to make sure you return that promise and then use it in the router correctly.
In auth.js, make sure verify returns a promise - just add return!
return collection.find(query).limit(1).toArray(...)
And then, change your usage of the verify to the async/await you originally tried:
router.get('/list/:uid', async function(req, res) {
var user = await auth.verify(req.params.uid, req.get("token"))
// More code here...
})

Mysql node.js async, wait for query to complete

Been trying everything to get this to work specifically the async each method. for (const element of resultsHistory) didn't work either.
I'm trying to modify the result array from a previous query by running a foreach over it and doing a mysql query.
However this needs to wait for the query to complete.
Is there a way to access these results without the setTimeout(function() { } I put manually in order to wait for the query to finish?
function getUserLikes(params, callback) {
var usersArrayCat = [];
console.log(`length of array ${params.length}`)
// 1 here means 1 request at a time
async.eachLimit(params, 1, function (element, cb) {
element.liked = 0;
var queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
connectionPromise.query(queryLiked, function (err, result) {
if (!result) {
} else if (result.length == 0) {
} else {
element.liked = result[0].userlike;
usersArrayCat.push(element);
// console.log(usersArrayCat);
cb();
}
})
}, function (err) {
if (err) return callback(err);
callback(null, usersArrayCat)
});
};
getUserLikes(resultsHistory, function (e) {
console.log(e);
});
if(!res.headersSent) {
setTimeout(function() {
res.send(JSON.stringify({"status": 200 ,"error": null, "top3":resultsHistory}));
}, 150);
}

Managed to get it working like this, but still not sure if this is the right way.
async function getUserLikes(resultsHistory) {
for (const element of resultsHistory) {
element.liked = 0;
let queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
let liked = await conn2.query(queryLiked);
if (liked[0]) {
element.liked = liked[0].userlike;
}
}
if(!res.headersSent) {
conn2.release();
let newres = resultsHistory.sort(
firstBy(function (v1, v2) { return v2.rating - v1.rating; })
.thenBy(function (v1, v2) { return v2.dranktimes - v1.dranktimes; })
).filter( function(history) {
return history.event === eventName;
}).slice(0, 3);
res.send({"status": 200 ,"error": null, "top3":newres});
}
}
getUserLikes(resultsHistory);

See my answer:
function getUserLikes(params, callback) {
var usersArrayCat = [];
console.log(`length of array ${params.length}`)
// 1 here means 1 request at a time
async.eachLimit(params, 1, function (element, cb) {
element.liked = 0;
var queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
connectionPromise.query(queryLiked, function (err, result) {
if (!result) {
} else if (result.length == 0) {
} else {
element.liked = result[0].userlike;
usersArrayCat.push(element);
// console.log(usersArrayCat);
}
cb();
})
}, function (err) {
if (err) return callback(err);
callback(null, usersArrayCat)
});
};
getUserLikes(resultsHistory, function (e, usersArrayCat) {
if (e) {
console.log(e);
return res.send({status: 400, error: e}); // your error response
}
console.log(usersArrayCat); // your usersArrayCat with liked property
res.send(JSON.stringify({ // why your need return a string intead of json object ???
"status": 200,
"error": null,
"top3": usersArrayCat // I think return `usersArrayCat` is a right way
}));
});

How promise works with nested function calls

I have a piece of code which deals with user's data. There are bunch of nested function calls :
f1(){
f2(){
....
fn{
///
}
}
}
fn accesses a database which means it's asynchronous, so I wrote it somehow that it returns a promise and in fn-1 (the function which calls fn) , we use .then() to wait for this promise. But it looks like now I have to return a promise in fn-1 and so on. Is that true ?
var keyValueExists = function(key, value) {
var query = {};
query[key] = value;
return new Promise(function(resolve, reject) {
User.count(query, function(err, count) {
if (err) {
console.log(err);
console.log('Problem with `.find` function');
reject('Problem with `.find` function');
} else {
resolve(count !== 0);
}
});
});
};
var addUser = function(newUserInfo) {
var validationResult = Common._validateUserInfo(newUserInfo);
if (validationResult.isOK) {
keyValueExists('userName', newUserInfo.userName).then(function(userNameAlreadyExists) {
if (userNameAlreadyExists) {
validationResult = {
isOK: false,
reason: 'Username already exists',
infoWithBadInput: 'userName'
}
} else {
var newUserId = generateUserId();
//TODO: change it somehting more flexible. e.g. a predefined list of attributes to iterate over
var newUser = {
'userName': newUserInfo.userName,
'password': newUserInfo.password,
'userId': newUserId,
'lastModificationTime': Common.getCurrentFormanttedTime(),
'createdTime': Common.getCurrentFormanttedTime()
};
var user = new User(newUser);
user.save(function(err) {
if (err) {
console.log(err);
console.log('There is a problem saving the user info');
} else {
console.log('A new user added: ');
console.log(newUser);
}
});
}
return validationResult;
});
} else {
return validationResult;
}
};
addUser returns undefined ! It looks like that the caller of addUser doesn't wait for it !

This is what you are effectively doing in your addUser function
var addUser = function(newUserInfo) {
var validationResult = Common._validateUserInfo(newUserInfo);
if (validationResult.isOK) {
// ... do something asynchronously without returning anything
} else {
return validationResult;
}
}
So, yeah, if validationResult.isOK, adduser WILL return undefined
Here's some code loosely based on your code, but it runs standalone to demonstrate how you possibly should be doing things
var keyValueExists = function(key, value) {
// pseudo junk, this simulates any username starting with b as existing
return new Promise(function(resolve, reject) {
resolve(value.substr(0,1) == 'b'); // barny and betty are dupes, fred and wilma are not
});
}
var addUser = function (newUserInfo) {
// var validationResult = Common._validateUserInfo(newUserInfo);
var validationResult = {isOK: !!~(['fred', 'barny'].indexOf(newUserInfo.userName)), username: newUserInfo.userName}; // dummy code
if (validationResult.isOK) {
return keyValueExists('userName', newUserInfo.userName).then(function (userNameAlreadyExists) {
if (userNameAlreadyExists) {
validationResult = {
isOK: false,
reason: 'Username already exists',
infoWithBadInput: 'userName',
username: newUserInfo.userName
}
} else {
// create new user here
validationResult.userNumber = (Math.random() * 100000000) | 0;
}
return validationResult;
});
}
else {
// this function always needs to return a promise, even if it is resolved/rejected immediately
return Promise.reject(validationResult);
}
}
addUser({userName: 'fred'}).then(function (result) {
console.log(result);
}).catch(function(err) {
console.error(err);
});
addUser({userName: 'wilma'}).then(function (result) {
console.log(result);
}).catch(function(err) {
console.error(err);
});
addUser({userName: 'barny'}).then(function (result) {
console.log(result);
}).catch(function(err) {
console.error(err);
});
addUser({userName: 'betty'}).then(function (result) {
console.log(result);
}).catch(function(err) {
console.error(err);
});

Nodejs events firing multiple times

If a message comes in for server01, both server01 and server02's message events will be triggered. I thought the line
Socket.prototype = new events.EventEmitter;
would result in completly seperate event instances
Thanks for any help!
var events = require('events');
var uuid = require('uuid');
// Server class
function Socket (host) {
var self = this;
self.options = {
"serverHost": host,
"serverName": "server",
"clientName": uuid.v4()
};
self.socket = new require('zmq').socket('router');
self.socket.identity = self.options.clientName;
self.socket.connect('tcp://' + self.options.serverHost);
self.socket.on('message', function (sender, data) {
console.log('Sender: %s', self.options.clientName);
console.log('Data: %s', data.toString());
self.emit('message', sender, data);
});
setInterval(function () {
self.socket.send([self.options.serverName, uuid.v4()]);
}, 5000);
self.send = function (obj, callback) {
var status = true;
if(obj !== 'object') {
status = false;
} else {
self.socket.send([self.options.serverName, obj]);
}
if(callback === 'function') {
callback(status);
} else {
return status;
};
};
};
Socket.prototype = new events.EventEmitter;
// Userland
var server01 = new Socket('127.0.0.1:3000');
server01.on('message', function (sender, data) {
console.log('Server01: %s', data.toString());
});
var server02 = new Socket('127.0.0.1:3000');
server02.on('message', function (sender, data) {
console.log('Server02: %s', data.toString());
});
Here is an example of the output from this script
Sender: 14d36a66-a4e7-484a-9ce0-3f0d368a6986
Data: 03e6bb47-6af0-4700-9b95-7bbc310477f6
Server01: 03e6bb47-6af0-4700-9b95-7bbc310477f6
Server02: 03e6bb47-6af0-4700-9b95-7bbc310477f6
Sender: 59ec292e-abd2-4c9f-ac3e-2bf92c656fde
Data: d66cd320-c3f2-4842-b66b-1d89f656d32f
Server01: d66cd320-c3f2-4842-b66b-1d89f656d32f
Server02: d66cd320-c3f2-4842-b66b-1d89f656d32f

The problem is the way you manage inheritance. Correct JavaScript code for inheritance is:
Socket.prototype = Object.create(EventEmitter.prototype);