Develop Reference

JS Script using DOM running on pm2 server

I have read that serverside, you cant use DOM. I've created a web application using DOM and I wonder what needs to be done to reproduce this code to make it work on a server, so the people on the internet can work with it. Here is a little peak of a code:
// Listen for export button click
document.getElementById('exportForm').addEventListener('submit', function (e) {
setTimeout(exportData, 20);
e.preventDefault();
});
// Export data function
function exportData(e) {
console.log("Exporting...");
// device details and time range details
const devId = (document.getElementById('deviceInput')).value;
var dateFrom = (document.getElementById('dateFromInput')).value;
var dateTo = (document.getElementById('dateToInput')).value;
var timeFrom = (document.getElementById('timeFromInput')).value;
var timeTo = (document.getElementById('timeToInput')).value;
const limit = (document.getElementById('limitInput')).value;
const key = (document.getElementById('keysInput')).value;
When I try to run it on server using pm2 start app.js, it returns this error:
ReferenceError: document is not defined
at Object.<anonymous> (/home/cloud/sites/App/app.js:6:1)
at Module._compile (internal/modules/cjs/loader.js:999:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
at Module.load (internal/modules/cjs/loader.js:863:32)
at Function.Module._load (internal/modules/cjs/loader.js:708:14)
at Object.<anonymous> (/usr/lib/node_modules/pm2/lib/ProcessContainerFork.js:33:23)
at Module._compile (internal/modules/cjs/loader.js:999:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
at Module.load (internal/modules/cjs/loader.js:863:32)
at Function.Module._load (internal/modules/cjs/loader.js:708:14)
I've heard about JSDom, but I think there needs to be html included in a string and then I have no idea how to connect the css in there and so on. Is there a better way for me to make this work?

Document object is a browser feature hence you cant use it inside server, Instead you have other features like the FS (File System)
Anyhow using JSDom may be possible, you have to rewrite using inline styles https://www.codecademy.com/article/html-inline-styles which is not a good practice and you should avoid it

is there a problem with this expression {item_1.name: req.body.item } or alternatively with this {[item_1.name]: req.body.item }?

I'm trying to run this piece of code:
router.put('/restaurants/:id', async (req, res) => {
try {
const response = await Restaurant.findByIdAndUpdate(req.params.id, {name: req.body.name,
item_1.name: req.body.item,
item_2.name: req.body.item_2,
item_3.name: req.body.item_3,
item_4.name: req.body.item_4
})
res.send(response)
}
catch (error) {
res.send(error)
}
})
where the scenario is I have items (i.e item_1 etc) saved as objects in database, items got two properties name and rating, when admin wants to edit an item it should only be able to just edit the name property of an item not the rating, so for implementing this what i'm trying to do is, upon edit request as shown here, I want to set only the name property of an item as same to what has been sent in the request.
but it gives me a typescript error (though I don't have typescript installed) saying:
',' expected.ts(1005)
and it happens before running this code, actually vs code is showing this error.
and upon running it is showing something like this:
E:\xord\second_assignment\node\routes\restaurants.js:50
item_1.name: req.body.item,
^
SyntaxError: Unexpected token '.'
at wrapSafe (internal/modules/cjs/loader.js:1054:16)
at Module._compile (internal/modules/cjs/loader.js:1102:27)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
at Module.load (internal/modules/cjs/loader.js:986:32)
at Function.Module._load (internal/modules/cjs/loader.js:879:14)
at Module.require (internal/modules/cjs/loader.js:1026:19)
at require (internal/modules/cjs/helpers.js:72:18)
at Object.<anonymous> (E:\xord\second_assignment\node\index.js:8:21)
at Module._compile (internal/modules/cjs/loader.js:1138:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
at Module.load (internal/modules/cjs/loader.js:986:32)
at Function.Module._load (internal/modules/cjs/loader.js:879:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
at internal/main/run_main_module.js:17:47
[nodemon] app crashed - waiting for file changes before starting...
same thing happens with a different error when i try to access the object property with bracket notation.
I apologise for the very long query but I'm wondering; is the syntax I've used in this code for setting the value of an object's key inside another object, incorrect? if so then why? also what would be the alternative way to do this?

thanks God! in mongoose v5.10.19 documentation I saw almost the same instance where they use a property of an object as a key of another object here:
Parent.update({}, { 'child.name': 'Luke Skywalker' }, (error) => {
// Error because parentSchema has `strict: throw`, even though
// `childSchema` has `strict: false`
});
by which I learnt that in such cases one should wrap the key in quotes as they did in "child.name". and that resolved the issue i was facing.

Discord.js module error before first line of code

I just started writing a Discord bot in Visual Studio Code in Javascript, it's literally the most basic it can be, loading discord.js, on ready event and then login.
Before it even runs the first line of code, I get this error:
Debugger listening on ws://127.0.0.1:5489/3cf4a3d1-ef26-4c1c-a274-030564d40731
For help see https://nodejs.org/en/docs/inspector
i:\Coding\Bots\PURGE\node_modules\discord.js\src\util\Util.js:584
str = str.replace(/#([^<># ]*)/gmsu, (match, target) => {
^
SyntaxError: Invalid regular expression flags
at createScript (vm.js:80:10)
at Object.runInThisContext (vm.js:139:10)
at Module._compile (module.js:607:28)
at Object.Module._extensions..js (module.js:654:10)
at Module.load (module.js:556:32)
at tryModuleLoad (module.js:499:12)
at Function.Module._load (module.js:491:3)
at Module.require (module.js:587:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (i:\Coding\Bots\PURGE\node_modules\discord.js\src\index.js:3:14)
Process exited with code 1
The error occurs in the Discord.js module which I didn't write, and have no idea how it works and therefore cannot fix.
Re-installling Discord.js didn't help, reinstalling Visual Studio Code didn't either.
I sent a friend the exact same files (even the same node_modules folder) and when he runs it, it works with no problems. Any ideas what the problem is or how I can fix it?
This is my code:
console.log("test") //DOESNT LOG
const Discord = require("discord.js");
const fs = require("fs");
const config = require("./config.json");
let christian = {}
//This will define our bot
var bot = new Discord.Client()
bot.on('message', async msg => {
console.log(msg)
})
bot.on('ready', () => {
console.log(`-----Purge#2420 Online-----\nWatching over ${bot.guilds.cache.size} servers |`)
});
bot.login(config.token)

From the comments:
I am on [Node] v8.9.4, [...] on Discord.js V12
From Discord JS' upgrade guide::
v12 requires Node 12.x or higher to use, so make sure you're up-to-date.
That is -- you'll have to upgrade your Node.js.

In the ready event you have an invalid string which maybe causing the error '-----Purge#2420 Online-----\nWatching over ${bot.guilds.cache.size} servers | it maybe crashing due to the invalid single quote ' at string's start, try replacing it with a backtick (`).
Read more about template strings here

mocha describe 'unexpected string error'

I am writing the below test cases using Mocha in node.js. Please find the below code :
describe('Car', function() {
it('can park?',function()
{
const car = new Car();
assert.equal(car.park(),'stopped'); }); });
I am running this using following command :
npm run test
It populates following error :
> inbox#1.0.0 test /Users/abc/test/
> mocha
/Users/abc/test/Inbox.test.js:18
describe('Car', function() {
^^^^^
SyntaxError: Unexpected string
at new Script (vm.js:74:7)
at createScript (vm.js:246:10)
at Object.runInThisContext (vm.js:298:10)
at Module._compile (internal/modules/cjs/loader.js:670:28)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
at Module.load (internal/modules/cjs/loader.js:612:32)
at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
at Function.Module._load (internal/modules/cjs/loader.js:543:3)
at Module.require (internal/modules/cjs/loader.js:650:17)
at require (internal/modules/cjs/helpers.js:20:18)
Can you please help me, what i am doing wrong here?
Note : package.json is also updated with mocha in scripts field.

I know i am answering to my own question but its more like recording it for others.
Just Use following statement in your code at top or before describe statements
"use strict";

Creating JS library Warning instead of Error

I am creating my own JS library with NPM. I want to give the users of my library a warning but not an error, however, I want my users to have a stacktrace of the warning that I log inside my library. So to get the stacktrace, I use new Error().stack. The problem with this is (1) the word 'Error' appears in the stacktrace by default and (2) the stack trace is the same for Node and Chrome but different for Mozilla.
So my question is - what is the best way to create a warning message that has a stacktrace, but that doesn't look like an error? Chrome and Node.js are aligned and I could simply remove the first element of the stack array before calling toString() on it. But the problem is that this wouldn't work for Mozilla.
Anyway, this is what I currently do in my library when there should be a warning emitted:
var err = new Error('looks like you have called IdempotentJSON.parse on an object that was already parsed');
console.error(err.message.concat('\n'),err.stack);
this "logs a warning" that looks like this
in Chrome
looks like you have called IdempotentJSON.parse on an object that was already parsed
Error: looks like you have called IdempotentJSON.parse on an object that was already parsed
at IdempotentJSON.parse (http://localhost:3000/static/vendor/idempotent-json.js:11:23)
at Backbone.Model.extend.persistModel.save.success (http://localhost:3000/static/app/js/models/userModel.js:88:56)
at Object._.extend.save.options.success (http://localhost:3000/static/vendor/backbone.js:620:30)
at jQuery.Callbacks.fire (http://localhost:3000/static/vendor/jquery.js:3099:30)
at Object.jQuery.Callbacks.self.fireWith [as resolveWith] (http://localhost:3000/static/vendor/jquery.js:3211:7)
at done (http://localhost:3000/static/vendor/jquery.js:8264:14)
at XMLHttpRequest.jQuery.ajaxTransport.send.callback (http://localhost:3000/static/vendor/jquery.js:8605:9)
in Mozilla Firefox:
"looks like you have called IdempotentJSON.parse on an object that was already parsed
" "IdempotentJSON.prototype.parse#http://localhost:3000/static/vendor/idempotent-json.js:11:23
#http://localhost:3000/static/app/js/app.js:157:30
Backbone.batchSyncCollection/<#http://localhost:3000/static/app/js/app.js:141:16
jQuery.Callbacks/fire#http://localhost:3000/static/vendor/jquery.js:3099:10
jQuery.Callbacks/self.fireWith#http://localhost:3000/static/vendor/jquery.js:3211:7
done#http://localhost:3000/static/vendor/jquery.js:8264:5
.send/callback/<#http://localhost:3000/static/vendor/jquery.js:8605:1
in Node.js
looks like you have called IdempotentJSON.parse on an object that was already parsed
Error: looks like you have called IdempotentJSON.parse on an object that was already parsed
at IdempotentJSON.parse (/Users/amills001c/WebstormProjects/first_comcast/node_modules/idempotent-json/index.js:9:19)
at Object.<anonymous> (/Users/amills001c/WebstormProjects/first_comcast/IJSONexp/ijson.js:8:15)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Function.Module.runMain (module.js:501:10)
at startup (node.js:129:16)
at node.js:814:3
one quick solution that would work for Node.js and Chrome would be to remove the first line of the stack trace that says "Error:...".
But this call is not valid:
err.stack.shift(); //error
apparently the stack is not an Array in JS?
And this wouldn't work for Mozilla anyway.
Is my best bet another library that checks which environment/browser that it's in? Like this:
http://www.eriwen.com/javascript/js-stack-trace/
it's 2015! By the way Mozilla, Chrome and Node have it right with the stack trace, I can click on the stack trace in Chrome and Node and it takes me to the files involved, doesn't seem like I can do this in Firefox.
What I want is something that looks like this:
Warning: looks like you have called IdempotentJSON.parse on an object that was already parsed
at IdempotentJSON.parse (http://localhost:3000/static/vendor/idempotent-json.js:11:23)
at Backbone.Model.extend.persistModel.save.success (http://localhost:3000/static/app/js/models/userModel.js:88:56)
at Object._.extend.save.options.success (http://localhost:3000/static/vendor/backbone.js:620:30)
at jQuery.Callbacks.fire (http://localhost:3000/static/vendor/jquery.js:3099:30)
at Object.jQuery.Callbacks.self.fireWith [as resolveWith] (http://localhost:3000/static/vendor/jquery.js:3211:7)
at done (http://localhost:3000/static/vendor/jquery.js:8264:14)
at XMLHttpRequest.jQuery.ajaxTransport.send.callback (http://localhost:3000/static/vendor/jquery.js:8605:9)

Looking into the source of console.trace you can try this for chrome & node.js:
function warning(message) {
var err = new Error;
err.name = 'Warning';
err.message = message; //or use util.format in nodejs
Error.captureStackTrace(err, warning); // this is to prevent `warning` function being included in the stack.
return err;
};
console.log(warning('message').stack);
In nodejs, this outputs:
Warning: message
at Object.<anonymous> (/home/ubuntu/workspace/warning.js:9:13)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Function.Module.runMain (module.js:501:10)
at startup (node.js:129:16)
at node.js:814:3
Unfortunately firefox doesn't have captureStackTrace method. So you have to call the above directly without wrapping it in a function.