MongoRuntimeError Unable to parse with URL - mongodb

Question

I am trying to connect to a mongo db using the nodejs mongo driver and I'm doing this in a cypress project. I get the error in the title. Below is the simplified version of my code.
import {MongoClient} from 'mongodb';
export class SomeRepository {
static insertSomething(): void {
// Error in the line below: MongoRuntimeError Unable to parse localhost:27017 with URL
const client = new MongoClient('mongodb://localhost:27017');
}
}
Mongodb is running because I can connect from the terminal. Also tried replacing localhost with 127.0.0.1 and adding the authSource parameter to the connection string.
The reason I'm mentioning cypress is because in a simple node project that only connects to mongodb everything works as expected. Package.json below
{
"name": "e2e",
"version": "1.0.0",
"description": "",
"main": "index.js",
"dependencies": {
"cypress": "10.8.0",
"cypress-wait-until": "1.7.2",
"headers-utils": "3.0.2",
"mongodb": "4.10.0",
"otplib": "12.0.1",
"pg": "8.7.3",
"pg-native": "3.0.1",
"typescript": "4.9.3"
}
}

Answer 1

The error is in the way you are passing the url, it is necessary that you follow a pattern, in mongodb to connect you need to have this pattern that I will pass below:
Format:
mongodb://<user>:<password>#<host>
Format with filled values:
mongodb://root:mypassword#localhost:27017/

Answer 2

The reason it’s not working is because you’re calling a NodeJS library in a cypress test. Cypress tests run inside a browser and cannot run nodejs libraries.
If you wanted to execute nodejs code in cypress you must create a cypress task https://docs.cypress.io/api/commands/task#Syntax
// cypress.config.js
import { SomeRepository } from ‘./file/somewhere’
module.exports = defineConfig({
e2e: {
setupNodeEvents(on, config) {
on(‘task’, {
insertSomething() {
return SomeRepository.insertSomething();
}
}
}
}
})
// to call in a cypress test
it(‘test’, function () {
cy.task(‘insertSomething’).then(value => /* do something */);
}
});