Why node.js always says I'm connected to my MongoDB even if the "URI" is fake or wrong?

Question

I'm testing mongoDB connection in node.js with mongoose. I follow the official guide of mongoose and when I try to connect like they said, mongoose always says I'm connected even if the URI given is fake or wrong. Is my connection trying correct ?

I want to connect my app to a database called 'technicaltest'.

My code:

const mongoose = require('mongoose');

const db = mongoose.createConnection('mongodb://localhost/technicaltest', {useNewUrlParser: true});

db.on('connected', () => {
    console.log('Connected to mongoDB !');
});

db.on('disconnected', () => {
    console.log('Disconnected to mongoDB !');
});

The console ouput:

> set PORT=3001 && node bin/www

Connected to mongoDB !

Same output for this code:

const mongoose = require('mongoose');

const db = mongoose.createConnection('mongodb://localhost/someWeirdyThingsHere', {useNewUrlParser: true});

db.on('connected', () => {
    console.log('Connected to mongoDB !');
});

db.on('disconnected', () => {
    console.log('Disconnected to mongoDB !');
});

I think if mongoose cannot connect to the right database in mongoDB nothing will be prompted in the console... But here... The 'connected' event is call anyway.

Answer 1

I think you forgot to add the port(27017) to your mongodb connection. It should be

const db = mongoose.createConnection('mongodb://localhost:27017/technicaltest', {useNewUrlParser: true});