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Extended Array Class in Javascript: How should I create helper functions to modify Array without assigning a new reference?

This is a socket.io lobby library for managing the users list.
I created an Array extension class with custom methods. My removeUser method does not work.
Logging shows that inside of the method, it does work - the user has been removed.
Logging outside shows no change.
I believe my issue is one of references. The reference in index.js 'userList' is one reference.
var userList = require("./userList")();
However when I reassign userList in the method, it creates another reference.
userArray = result;
This newly-created reference is not known by the index.js, which sees no change in the userList object.
index.js
My server (simplified for example)
const express = require("express");
const bodyParser = require("body-parser");
const app = express();
const server = require("http").createServer(app);
const io = require("socket.io")(server);
var userList = require("./userList")();
io.on("connection", (socket) => {
// get user from session
userList.addUser(s_user);
socket.on("disconnect", () => {
userList.removeUser(s_user);
});
});
userList.js (Original)
An extended Array class for managing the list of users in my lobby.
function createUserList() {
let userArray = [];
userArray.addUser = (user) => {
userArray.push(user);
};
userArray.removeUser = (user) => {
let userId = user.user_id;
for (let i = 0; i < userArray.length; i++) {
if (userArray[i]["user_id"] === userId && userId !== undefined) {
let firstHalf = userArray.slice(0, i);
let secondHalf = userArray.slice(i+1, userArray.length);
let result = firstHalf.concat(secondHalf);
userArray = result;
}
}
};
return userArray;
}

My Solution
My solution was to create a closure. An array manager object contains the methods for userList management, and through a closure has access to the userArray. (code below this paragraph)
Pros
The userArray can modified or reassigned without reference issue (within the userList library)
userArray = [] //ok
(I also don't have to re-attach methods on re-assignment)
Cons
I can't use Array prototype methods
let length = userList.length // method doesn't exist on management object
let listCopy = userList // returns an object, not the list
I must use my custom built methods
let length = userList.getLength()
let listCopy = userList.getList()
Does anyone have other interesting solutions?
userList.js (V2)
function createUserList() {
let userArray = []
let arrayManager = {
addUser: (user) => {
userArray.push(user);
},
removeUser: (user) => {
let userId = user.user_id;
for (let i = 0; i < userArray.length; i++) {
if (userArray[i]["user_id"] === userId && userId !== undefined) {
let firstHalf = userArray.slice(0, i);
let secondHalf = userArray.slice(i+1, userArray.length);
let result = firstHalf.concat(secondHalf);
userArray = result;
}
}
},
getList: () => {
return userArray;
},
getLength: () => {
return userArray.length;
}
};
return arrayManager;
}
module.exports = createUserList;

ForEach only looping through first item on DataSnapshot

I´m trying to loop through the content of a DataSnapshot and then depending on a condition do some work FOR EACH one of the elements but currently, the ForEach is only doing the work in the first item. The "serverStatus" sometimes is waiting and sometimes in "onCall". When the first item is "onCall" does not go through the rest of the items as I think is supposed to do. Below a snapchot of where I get the information from:
And here is my function:
exports.manageCallRequests = functions.database.ref('/resquests/{userId}').onCreate((snap, context) => {
const event = snap.val();
console.log("function manageCallRequests is being called")
var rootPath = admin.database().ref();
var userOnCall = context.params.userId;
var serversRef = rootPath.child('servers');
var callRequest = event;
var userTime = callRequest["time"];
var waiting= "waiting";
//We first get all the servers in ascending order depending on the last time they were used
var serversSorted = serversRef.orderByChild('lastTimeUsed')
//Gets the children on the "serversSorted" Query
return serversSorted.once("value").then(allServers =>{
//Checks if there is any child
if(allServers.hasChildren()){
allServers.forEach(async function(server) {
//we extract the value from the server variable, this contains all the information
//about each one of the servers we have
var serverInfo = server.val();
var serverKey = server.key;
var serverNumber = serverInfo["serverNumber"];
var serverStatus = serverInfo["serverStatus"];
console.log("server status "+serverStatus)
if(serverStatus === waiting){
const setCallRequest = await serversRef.child(serverKey).child("current").child("callRequest").set(callRequest);
const removeUserOnCall = await rootPath.child("resquests").child(userOnCall).remove();
const setServerStatus = await serversRef.child(serverKey).child("serverStatus").set("onCall");
}
});
}else{
console.log("No servers available")
}
});
});

I had the same behavior because my cloud function was exited before that all iterations were executed in the forEach loop.I get rid of it using this snippet of code:
for (const doc of querySnapshot.docs) {
// Do wathever you want
// for instance:
await doc.ref.update(newData);
}

I found 2 ways of getting this done. The first one is useful if we have a DataSnapshot without any OrderBy* call, in this case, would be:
var allServers = await serversRef.once("value");
for (let serverKey of Object.keys(allServers.val())){
var server = allServers[serverKey];
//Do some work
}
We need to first get the keys of the object to then be able to extract it from within the for loop, as explained here otherwise we´ll get a "TypeError: 'x' is not iterable"
Now the problem with this particular case is that a have a DataSnapshot that was previously sorted at var serversSorted = serversRef.orderByChild('lastTimeUsed') so when we call Object.keys(allServers.val()) the value returned is no longer sorted and that´s where forEach() comes in handy. It guarantees the children of a DataSnapshot will be iterated in their query order as explained here however for some reasons when doing some async work within the forEach loop this seems not to work, that´s why I had to do this:
var serversSorted = serversRef.orderByChild('lastTimeUsed')
var allServers = await serversSorted.once("value");
//Checks if there is any children
if (allServers.hasChildren()) {
//if there is iterate through the event that was passed in containing all
// the servers
var alreadyOnCall = false;
var arrayOfServers = []
var arrayOfKeys = []
allServers.forEach(function(individualServer){
arrayOfKeys.push(individualServer.key)
arrayOfServers.push(individualServer)
})
for (var serveIndex = 0; serveIndex < arrayOfServers.length;serveIndex++){
var serverObj = arrayOfServers[serveIndex]
var serverObject = serverObj.val()
var serverKey = arrayOfKeys[serveIndex]
var serverStatus = serverObject["serverStatus"];
var serverNumber = serverObject["serverNumber"];
console.log("server info "+serverStatus+" "+serverKey);
if (serverStatus === waiting && alreadyOnCall === false) {
const setCallRequest = await serversRef.child(serverKey).child("current").child("callRequest").set(callRequest);
const removeUserOnCall = await rootPath.child("resquests").child(userOnCall).remove();
const setServerStatus = await serversRef.child(serverKey).child("serverStatus").set("onCall");
alreadyOnCall= true
console.log("Call properly set");
}
}
}

forEach with single document firebase queries in client side?

I have different document id for every loop and when I query inside the forEach loop query is working but not pushing the obj into the array
function getAllDonations() {
donations = [];
const user_session_data = sessionStorage.getItem('LoginInfo');
const parse_user_login_data = JSON.parse(user_session_data);
let TABLE_NAME = "donation_favourites";
let get_requests_qry = App.db.collection(TABLE_NAME);
get_requests_qry.where('user_id', '==', parse_user_login_data.user_id).get().then(snapshot => {
let changes = snapshot.docChanges();
changes.forEach(change => {
var one_item = change.doc.data();
let TABLE_NAME1 = "donation_requests";
let get_requests_qry1 = App.db.collection(TABLE_NAME1);
get_requests_qry1.doc(one_item.donationId).get().then(snapshot => {
donations.push(snapshot.data())
});
});
console.log("checking the data",donations.length) //this length is not coming
});
}

If you want to read the files in use forloop but it is not recommended for large loop for small loop it is ok
if you want to read files parallel use forEach
You can also do it with async and await instead forLoop
await Promise.all(changes.map(async (change) => {
var one_item = change.doc.data()
let TABLE_NAME1 = "donation_requests";
let get_requests_qry1 = App.db.collection(TABLE_NAME1);
var snapshot1 = await get_requests_qry1.doc(one_item.donationId).get()
donations.push(snapshot1.data())
}));

Update an Object in indexed db by ignoring a value

I have written the below code
updatePublication(projectName, publicationId, publicationObj, callback) {
let self = this;
this.initDatabase(function (db) {
let tx = self.db.transaction(self.PUBLICATIONS, self.READ_WRITE);
let store = tx.objectStore(self.PUBLICATIONS);
let index = store.index(self.PROJECT_NAME);
let request3 = index.openCursor(IDBKeyRange.only(projectName));
console.log("hrere");
request3.onsuccess = function () {
let cursor = request3.result;
if (cursor) {
let updateObject = cursor.value;
if (updateObject.publicationID == publicationId) {
updateObject.publicationObject = publicationObj;
cursor.update(updateObject);
callback(publicationId);
}
cursor.continue();
} else {
callback(publicationId);
}
};
});
}
But this give error:
I checked the cause of error. It is beacuse , publicationObj which is passed has an object named _requestObjectBuilder which is of the type Subscriber.
used somewhere in the code like this:
_requestObjectBuilder = interval(1000).pipe(tap(() => {}));
Is there any way i can modify my updatePublication code to ignore this value?
Does indexed db support a query for ignoring a value and saving the data?
Note: If i set publicationObj._requestObjectBuilder = undefined, the data gets saved to indexedDB. But this breaks the functionality where _requestObjectBuilder is used.

Fixed the issue by cloning the object and setting it to undefined
let clonedObject = Object.assign({}, publicationObject);
clonedObject._requestObjectBuilder = undefined;
Now i am updating the clonedObject

global variable is not accessible in firebase function

I declared a global array in index.js (firebase function). Once the code is deployed, this array is filled from firebase data.
I have two functions, in the first one (onTW) i made some changes to the array, and i'm just displaying it in the other function(onRemoveTW). The problem is I'm getting an empty array in the second function.
Here's my code.
var TWArray = [];
TWRef.once('value', function (snapshot) {
snapshot.forEach(function(childSnapshot) {
var name=childSnapshot.key;
var users = {};
var userNbr = 0;
TWRef.child(name).child('rm').once('value', function (snapshot2) {
snapshot2.forEach(function(childSnapshot2) {
userNbr++;
if(childSnapshot2.key=='a'){
users.a = childSnapshot2.val();
}
if(childSnapshot2.key=='b'){
users.b = childSnapshot2.val();
}
if(childSnapshot2.key=='c'){
users.c = childSnapshot2.val();
}
if(childSnapshot2.key=='d'){
users.d = childSnapshot2.val();
}
})
TWArray.push({
rmName:name,
users:users,
userNbr:userNbr
});
})
})
})
exports.onTW = functions.database
.ref('/Orders/TW/{requestId}')
.onWrite(event => {
const userKey = event.data.key;
const post = event.data.val();
if (post != null) {
var users={};
users.a=userKey;
TWArray.push({
rmName:userKey,
users:users,
userNbr:1
});
console.log(TWArray);
console.log("TWArray.length : "+TWArray.length);
}
});
exports.onRemoveTW = functions.database
.ref('/Orders/RemoveTW/{requestId}')
.onWrite(event => {
const userKey = event.data.key;
const post = event.data.val();
if (post != null) {
console.log("TWArray.length : "+TWArray.length);
}
})
Thanks in advance!

You cannot share data between functions by writing to global variables when using firebase-functions, because they intended to be stateless. As such, this functionality is not supported.
What you can do is write your data to firebase-database instead.