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How do I Collect User IDs + Retrieve Corresponding Tokens + Send a Push Notification Via Firebase Cloud Function (JS)

The Problem:
I have been unable to use Firebase (Google) Cloud Functions to collect and utilize device tokens for the cloud messaging feature.
Context:
I am a self-taught android-Java developer and have no JavaScript experience. Despite that, I believe I have code that should work and am not sure what the problem is. To my understanding, it could be one of three things:
Somehow my Firebase Realtime Database references are being called incorrectly and I am not retrieving data as expected.
I may need to use Promises to wait for all calls to be made before proceeding, however I don't really understand how I would incorporate that into the code I have.
I may be using multiple return statements incorrectly (which I am also fuzzy on).
My error message on the Firebase Realtime Database console is as follows:
#firebase/database: FIREBASE WARNING: Exception was thrown by user callback. Error: Registration token(s) provided to sendToDevice() must be a non-empty string or a non-empty array.
at FirebaseMessagingError.FirebaseError [as constructor] (/srv/node_modules/firebase-admin/lib/utils/error.js:42:28)
at FirebaseMessagingError.PrefixedFirebaseError [as constructor] (/srv/node_modules/firebase-admin/lib/utils/error.js:88:28)
at new FirebaseMessagingError (/srv/node_modules/firebase-admin/lib/utils/error.js:254:16)
at Messaging.validateRegistrationTokensType (/srv/node_modules/firebase-admin/lib/messaging/messaging.js:729:19)
at Messaging.sendToDevice (/srv/node_modules/firebase-admin/lib/messaging/messaging.js:328:14)
at admin.database.ref.once.snapshot (/srv/index.js:84:12)
at onceCallback (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:4933:51)
at /srv/node_modules/#firebase/database/dist/index.node.cjs.js:4549:22
at exceptionGuard (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:698:9)
at EventList.raise (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:9684:17)
The above indicates I am not retrieving data either at all or by the time the return is called. My JavaScript function code is:
'use strict';
const admin = require('firebase-admin');
admin.initializeApp();
exports.pushNotification = functions.database.ref('/Chat Messages/{chatId}/{pushID}').onCreate((snapshot, context) => {
const valueObject = snapshot.after.val();
return admin.database().ref(`/Chat Basics/${valueObject.chatKey}/Chat Users`).once('value', statusSnapshot => {
var index = 0;
var totalkeys = statusSnapshot.numChildren();
var msgIDs = [];
statusSnapshot.forEach(msg=>{
msgIDs.push(msg.key.toString());
if(index === totalkeys - 1){
const payload = {
notification : {
title: valueObject.userName,
body: valueObject.message,
sound: "default"
}
}
sendNotificationPayload(valueObject.uid, payload);
}
index++;
});
});
});
function sendNotificationPayload(uid, payload){
admin.database()
.ref(`/User Token Data/${uid}`)
.once('value', snapshot=> {
var tokens = [];
//if(!snapshot.exists())return;
snapshot.forEach(item =>{
tokens.push(item.val())
});
admin.messaging()
.sendToDevice(tokens, payload)
.then(res => {
return console.log('Notification sent')
})
.catch(err => {
return console.log('Error in sending notification = '+err)
});
});
}
This code is mostly inspired by what was said to be a working example here from another Stack Overflow question here. I have successfully tested sending a notification to a single device by manually copying a device token into my function, so the function does run to completion. My Java code seems to be irrelevant to the problem, so I have not added it (please ask in the comments if you would like it added for further context).
What I Have Tried:
I have tried implementing promises into my code, but I don't think I was doing it properly. My main reference for this was here. I have also looked at the documentation for literally everything related to this topic, however my knowledge of JS is not sufficient to really apply barebones examples to my code.
My Firebase Realtime Database Nodes:
#1: Loop through chat members to collect user IDs:
"Chat Basics" : {
"1607801501690_TQY41wIfArhHDxEisyupZxwyHya2" : {
"Chat Users" : {
"JXrclZuu1aOwEpCe6KW8vSDea9h2" : true,
"TQY41wIfArhHDxEisyupZxwyHya2" : true
},
#2: Collect user tokens from collected IDs (ignore that tokens are matching):
"User Token Data" : {
"JXrclZuu1aOwEpCe6KW8vSDea9h2" : "duDR3KH3i3I:APA91bH_LCeslZlqL8akYw-LrM9Dv__nx4nU1TquCS0j6bGF1tlIARcheREuNdX1FheC92eelatBC8LO4t6gt8liRdFHV-NDuNLa13oHYxKgl3JBPPlrMo5rB5XhH7viTo4vfYOMftRi",
"TQY41wIfArhHDxEisyupZxwyHya2" : "duDR3KH3i3I:APA91bH_LCeslZlqL8akYw-LrM9Dv__nx4nU1TquCS0j6bGF1tlIARcheREuNdX1FheC92eelatBC8LO4t6gt8liRdFHV-NDuNLa13oHYxKgl3JBPPlrMo5rB5XhH7viTo4vfYOMftRi"
}
Conclusion:
Concrete examples would be much appreciated, especially since I am crunching right now. Thanks for your time and help!
Update:
After some more testing, it looks like the problem is definitely due to my lack of understanding of promises in two areas. Firstly, only one user is collected before the final return is called. Secondly, the final return is called before the 2nd forEach() loop can store snapshot data to an array.
For this code then, how may I modify (or rebuild) it so that it collects all keys before proceeding to retrieve token data from all keys - ultimately before returning the notification?

Just as with every question I post, I managed to figure out how to do it (tentatively) a few hours later. Below is a full example of how to send a notification to chat users based on a message sent (although it does not yet exclude the sender) to a given chat. The order of operations are as such:
User message is saved and triggers event. Relevant data the message contains are:
username, chat key, message
These are retrieved, with (username + message) as the (title + body) of the
notification respectively, and the chat key is used for user id reference.
Loop through chat user keys + collect.
Loop through array of chat user keys to collect array of device tokens.
Send notification when complete.
The code:
//Use firebase functions:log to see log
exports.pushNotification = functions.database.ref('/Chat Messages/{chatId}/{pushId}').onWrite((change, context) => {
const valueObject = change.after.val();
return admin.database().ref(`/Chat Basics/${valueObject.chatKey}/Chat Users`).once('value', statusSnapshot => {
var index = 0;
var totalkeys = statusSnapshot.numChildren();
var msgIDs = [];
statusSnapshot.forEach(msg=>{
msgIDs.push(msg.key.toString());
if(index === totalkeys - 1){
const payload = {
notification : {
title: valueObject.userName,
body: valueObject.message,
sound: "default"
}
}
let promises = [];
var tokens = [];
for(let i=0; i < msgIDs.length; i++){
let userId = msgIDs[i];
let promise = admin.database().ref(`/User Token Data/${userId}`).once('value', snapshot=> {
tokens.push(snapshot.val());
})
promises.push(promise);
}
return Promise.all(promises).then(() => {
return admin.messaging().sendToDevice(tokens, payload);
});
}
index++;
return false;
});
});
});

Discord.js Bots // Trying to add multiple bots in main file, setting status', randomize welcome messages, multiple prefixes

I planned to create a discord server with bots. There are quite a lot (6 in total) and are just supposed to be fictional characters with some background story. I'm quite new and all of that is way too complicated for me to code myself, therefor I ask for your help! I just want to have a nice server for my friends and I with enjoyable bots and all of these desperate hours of trying to get some useful code is driving me nuts..
I only managed to get one bot to do stuff, using the prefix "-".
It can change it's status (watching, listening, playing) and the name of the thing he's doing.
I'm not quite sure why streaming doesn't work or if that's possible in general but it would be really cool if it would.
My status code: (1st Problem)
client.once('ready', () => {
console.log('Bot is ready!');
if (config.activity.streaming == true) {
client.user.setActivity(config.activity.game, {type: 'WATCHING'}); //STREAMING, PLAYING, LISTENING
} else {
client.user.setActivity(config.activity.game, {url: 'https://twitch.tv/usrname'});
client.user.setStatus('idle'); //dnd, idle, online, invisible
}
});
config.json
"activity": {
"streaming": true,
"game": "Whatevergame"
}
}
As I said, streaming is not working for some reason and the status (idle, dnd..) is also not working.
2nd Problem
If I try to add other bots with the login, it will log both bots on, but only one of them will work, what's actually pretty logical since the commands are all made for only one bot. So I'm trying to figure out how to get them all packed into the main file.
3rd Problem
I used the try - catch function to execute commands, which I pre- set up, and if theres none, it sends an error message. See for yourself:
client.on('message', message =>{
if (!message.content.startsWith(prefix) || message.author.bot) return;
const args = message.content.slice(prefix.length).split(/ +/);
const command = args.shift().toLowerCase();
try {
client.commands.get(command).execute(message, args);
}
catch {
message.channel.send("I don't know that, sorry.");
}
});
So everytime I type another command, from which I do not want the bot to respond to, it will respond with "I don't know[...]" It would be sufficient to just set up another prefix for the "other command" to fix that problem so the bot knows that for every prefix starting with a.e "-", it has to send an error message if that command is not existing. But for other prefixes, a.e "?", it's supposed to execute the other command/s.
4th Problem
My (current) last problems are the welcome messages. My code:
index.js
const welcome = require("./welcome");
welcome (client)
welcome.js
module.exports = (client) => {
const channelId = '766761508427530250' // welcome channel
const targetChannelId = '766731745960919052' //rules and info
client.on('guildMemberAdd', (member) => {
console.log(member)
const message = `New user <#${member.id}> joined the server. Please read through ${member.guild.channels.cache.get(targetChannelId).toString()} to gain full access to the server!`
const channel = member.guild.channels.cache.get(channelId)
channel.send(message)
})
}
The code is working perfectly fine, however it would be way more exciting with a little more variety. I'm trying to get multiple welcome messages that get randomly chosen by the bot.. I thought about a Mathfloor as an approach but I'm not quite sure how that would work..
Thank you for reading through my text and I hope that I will soon be able to enjoy the server with my guys!
Cheers!

First problem
I'm not sure why ClientUser.setActivity() and ClientUser.setStatus is not working. In the STREAMING example, it might be because you didn't specify the type of activity. Either way, there's an easier way to what you're doing, which is ClientUser.setPresence(). This method is kind of like a combination of the other two.
client.once('ready', () => {
console.log('Bot is ready!');
config.activity.streaming
? client.user.setPresence({
activity: { name: config.activity.game, type: 'WATCHING' },
})
: client.user.setPresence({
activity: {
name: config.activity.game,
type: 'STREAMING',
url: 'https://twitch.tv/usrname',
},
status: 'idle', // note: the idle icon is overwritten by the STREAMING icon, so this won't do much
});
});
Second Problem
It's pretty hard to make multiple bots, both duplicates of each other, in one file. I would recommend just using a lot of Array.prototype.forEach() loops to apply all events and such to both clients.
[1, 2, 3].forEach((num) =>
console.log(`The element I'm currently iterating a function through is ${num}`)
);
// example main file
const { Client, Collection } = require('discord.js');
const [roseClient, sunflowerClient] = [new Client(), new Client()];
// adding properties:
[roseClient, sunflowerClient].forEach((client) => client.commands = new Collection())
// events
[roseClient, sunflowerClient].forEach((client) =>
client.on('message', (message) => {
// ...
});
);
// login
roseClient.login('token1');
sunflowerClient.login('token2');
Third problem
Again, forEach() loops save the day (❁´◡`❁). This time, however, you should actually use Array.prototype.every(), which will return true if every element of an array passes the given test.
Basically, if we were to use a normal forEach() loop, then even if one of the prefixes found the match, the other wouldn't and the error message would always be sent out. So instead we'll use every() to only send out an error message if both prefixes find no match.
// what if we ony wanted the error message if *every* number was 3
[1, 2, 3].forEach((num) => {
if (num === 3) console.error('Error message');
});
console.log('--------------------');
// now it will only send if all numbers were three (they're not)
if ([1, 2, 3].every((num) => num === 3))
console.error('Error message');
client.on('message', (message) => {
if (['-', '?'].every((prefix) => {
if (!message.content.startsWith(prefix) || message.author.bot) return;
const args = message.content.slice(prefix.length).split(/ +/);
const command = args.shift().toLowerCase();
try {
// it did not pass the test (the test being finding no match), and the error message should not be displayed
return false;
client.commands.get(command).execute(message, args);
} catch {
// it did pass the test (by finding no match). if the next test is failed too, the error message should be displayed
return true;
message.channel.send("I don't know that, sorry.");
}
});
});
Fourth Problem
You're on the right track! Math.floor() is definitely the right way to get a random element from an array.
function chooseFood() {
// make an array
const foods = ['eggs', 'waffles', 'cereal', "nothing (●'◡'●)", 'yogurt'];
// produce a random integer from 0 to the length of the array
const index = Math.floor(Math.random() * foods.length);
// find the food at that index
console.log(`Today I will eat ${foods[index]}`);
};
<button onClick="chooseFood()">Choose What to Eat</button>
module.exports = (client) => {
client.on('guildMemberAdd', (member) => {
console.log(member);
const welcomes = [
`Welcome ${member}!`,
`Woah! Didn't see you there ${member}; welcome to the server!`,
`${member} enjoy your stay at ${member.guild}!`,
];
const message = `${
welcomes[Math.floor(Math.random() * welcomes.length)]
} Please read through ${member.guild.channels.cache.get(
'766731745960919052'
)} to gain full access to the server!`;
member.guild.channels.cache.get('766761508427530250').send(message);
});
};
That was a mouthful (╯°□°）╯︵ ┻━┻

Discord.js v12 role.delete() doesn't work

So, i was testing this out, and that when I use this code, it doesn't actually delete the roles, is this a bug?
On the code:
client.on('message', async message => {
message.guild.roles.fetch()
.then(r => r.forEach(s =>
s.delete()
));
})
I tried other variants as well such as:
client.on('message', async message => {
message.guild.roles.cache.forEach(r => r.delete());
});
client.on('message', async message => {
message.guild.roles.cache
.map(r => r.id)
.forEach(s =>
message.guild.roles.cache.find(l => l.id === s)
.delete()
);
});
client.on('message', async message => {
const roles = message.guild.roles.cache
.map(r => r.id);
for (m=0;m<roles.length;m++) {
message.guild.roles.cache.find(s => s.id === roles[m])
.delete();
}
});
I even tried to not mass delete and just delete one:
message.guild.roles.cache.find(s => s.id === 'ROLE_ID')
.delete();
None seemed to have worked, and they all return the same error:
TypeError: Cannot read property 'delete' of undefined
or
DiscordAPIError: Invalid Role
Though I'm 100% sure that the role does exist and is valid. This error only happens when I try to delete roles. When I tried checking the roles in the server using
message.guild.roles.cache.map(r => r.id);
it sometimes returns a blank array, though there are roles in the server.

It seems that the reason for this is because Discord Guilds have default roles, mainly, #everyone, and one with the bots name, which you can't delete.
I don't know exactly how to differentiate these "default" roles from created ones, but it seems like #everyone role seems to be always Role.rawPosition= 0 and the bots roles likes to take the last position of this same index. Also throughout my testing, seems like bot roles have Role.editable = false. Created ones, but also #everyone, has it = true. Which makes things a little confusing.
With that in mind, it's up to you to create the best algorithm for what you're trying to achieve. But I can promise it's unsafe.
If you can if yourself to roles that can be deleted, Node shouldn't crash.
(CURA GAMER BOT is my test bot, so the first role was not manually created)
I'd recommend you to log all your roles cache, at least for testing, and check the roles properties in other to find out what will suit you better. Whatever if your doubt was if role.delete() was reliable, yes it seems like. But I'd recommend deleting a single role at time, having the reference to its objects anyway.
Here are some tests that worked for me (screenshot scenario) which may or may not work for you (use at your own risk):
const roles = message.guild.roles.cache;
roles.forEach(role => {
// -1 because I have only on bot role
if(role.rawPosition > 0 && role.rawPosition < (roles.size - 1)) {
role.delete();
}
});
const roles = message.guild.roles.cache;
roles.forEach(role => {
if(role.editable && role.name !== '#everyone') {
role.delete();
}
});
The safest for me, delete based on timestamp:
const roles = message.guild.roles.cache;
roles.forEach(role => {
// Created after Tue Sep 08 2020 15:55:00 GMT-0500
if(role.createdTimestamp > 1599598514000) {
role.delete();
}
});

That's because Collection.delete() requires a key, not an object. Instead of passing the role object as an argument, you should be passing the role snowflake.
message.guild.roles.cache.delete('<Role ID>')
Also, to delete all roles, you can use the Collection.clear() method, which removes all elements from the collection.
message.guild.roles.cache.clear()

Bot not replying correctly in a private message

So, this code block is part of a code that player A (challenger) issues a challenge to player B (target) for a game. The bot sends a private message to player B to tell them they were challenged and to ask if they accept or decline the challenge.
The following code doesn't seem to respond to what player B replies with.
if (message.channel.id === '541736552582086656') return target.send("Do you accept the challenge? Please reply with 'accept' or 'deny'.")
.then((newmsg) => {
newmsg.channel.awaitMessages(response => response.content, {
max: 1,
time: 150000,
errors: ['time'],
}).then((collected) => {
if (collected === 'accept') {
newmsg.channel.send("You have ***accepted*** the challenge. Please wait while your battlefield is made...");
} else if (collected === 'deny') {
newmsg.channel.send("You have ***denied*** the challenge.")
}
}).catch(() => {
newmsg.channel.send('Please Accept or Deny the challenge.');
});
});
}
Prior to this code block, I set up logging a message to a channel on the server, sending the challenger and the target the challenge info. The bot successfully contacts the target that they were challenged via pm, but the reply (even when replying with "accept" will still think it was declined.
Thanks for any and all help!

Expanding upon #Stock Overflaw's answer, awaitMessages will always return a collection of fetched messages, meaning collected === 'accepted' won't work. You're checking if a collection object is the same as a string.
What you need is to grab the first (and in your case only) message from the collection and check its content against a string. Below you will find your .then(...) statement re-written. Give it a go and let me know what the result is.
P.s. your collection filter won't work as you might expect. The filter only checks if a message will be added to the collection or not. Since your 'filter' is response => response.content, it will only check if the response.content is not empty, null or undefined
.then((collected) => {
// Grabs the first (and only) message from the collection.
const reply = collected.first();
if (reply.content === 'accept'){
reply.channel.send("You have ***accepted*** the challenge. Please wait while your battlefield is made...");
} else if (reply.content === 'deny') {
reply.channel.send("You have ***denied*** the challenge.")
} else {
reply.channel.send("Your response wasn't valid.");
/*
* Code here to handle invalid responses
*/
}
})

Discord.js deleteMessage() doesn't work

I am creating a Discord bot with discord.js and I'd like to create a command that can clear messages. For now, I have this code (only the interesting part) and I can't figure out why it doesn't work:
// Importing discord.js, creating bot and setting the prefix
const Discord = require('discord.js');
const bot = new Discord.Client();
const prefix = "/";
// Array that stores all messages sent
messages = [];
bot.on('message', (message) => {
// Store the new message in the messages array
messages.push(message);
// Split the command so that "/clear all" becames args["clear", "all"]
var args = message.content.substring(prefix.length).split(" ");
// If the command is "/clear all"
if(args[0] == "clear" && args[1] == "all") {
bot.deleteMessages(messages); // Code that doesn't work
// Resets the array
messages = [];
}
}
// CONNECT !!!
bot.login('LOGING TOKEN HERE');
Can you help me ?

You should use <TextChannel>.bulkDelete instead.
Example:
msg.channel.bulkDelete(100).then(() => {
msg.channel.send("Purged 100 messages.").then(m => m.delete(3000));
});
This would delete 2 - 100 messages in a channel for every call to this method so you would not receive 429 (Too many Requests) Error frequently which might result in your token being revoked.

I see two problems:
the messages array is always empty; there is no code that adds items to the array, so the call to bot.deleteMessages will always get an empty array;
it does not appear that deleteMessages is an available method on Discord.Client;
Based on the documentation, I think what you want is sweepMessages. The description of that states:
Sweeps all text-based channels' messages and removes the ones older than the max message lifetime. If the message has been edited, the time of the edit is used rather than the time of the original message.
Try changing the code to instead call bot.sweepMessages(1);, which I think will tell the client to clear all messages older than one second.

Another way to do this, without sweepMessages is by using fetchMessages:
let user = message.mentions.users.first();
let amount = !!parseInt(message.content.split(' ')[1]) ? parseInt(message.content.split(' ')[1]) : parseInt(message.content.split(' ')[2])
var prefix = '!'
if (message.content.startsWith(prefix + 'clear') && !amount)
return message.reply('Must specify an amount to clear!');
if (message.content.startsWith(prefix + 'clear') && !amount && !user) return message.reply('Must specify a user and amount, or just an amount, of messages to clear!');
message.channel.fetchMessages({
limit: amount,
}).then((messages) => {
if (user) {
const filterBy = user ? user.id : bot.user.id;
messages = messages.filter(m => m.author.id === filterBy).array().slice(0, amount);
}
message.channel.bulkDelete(messages).catch(error => console.log(error.stack));
});
This will allow users to use the command !clear [#] to delete that number of messages when sent. If it is run as just !clear you can set how many get deleted, without a specified number.
discord.js Documentation - TextChannel#fetchMessages

You can swap
bot.deleteMessages()
to:
messages.forEach(x => x.delete())

Its not like that. you should fetch the messages first then use bulkDelete to delete them
, here is a simple example
// Normal Javascript
<Message>.channel.fetchMessages()
.then(messages => {
// Here you can use bulkDelete(101) to delete 100 messages instead of using fetchMessages and deleting only 50
<Message>.channel.bulkDelete(messages);
});
// ES6
let messages = await <Message>.channel.fetchMessages();
// Here you can use bulkDelete(101) to delete 100 messages instead of using fetchMessages and deleting only 50
await <Message>.channel.bulkDelete(messages);