How to Connect to MongoDB server from Node.js application?

Q: How to Connect to MongoDB server from Node.js application?

const { MongoClient } = require('mongodb'); // Connection URL (Typically from environment variables) const url = 'mongodb://localhost:27017'; const client = new MongoClient(url); // Database Name const dbName = 'myProject'; async function connect() { try { // Connect the client to the server await client.connect(); console.log('Connected successfully to MongoDB server'); const db = client.db(dbName); return db; } catch (err) { console.error('Connection failed', err); } } connect();

Difficulty: 4/10

connection string, authentication, connection pooling

MongoDB can be connected from Node by calling the connect() method of MongoClient class.

javascript

Scenario Questions

0-2 years experience

1We have a simple Node.js script that needs to read a collection from a local MongoDB. How would you establish the connection?
2If you forget to include the database name in the connection string, what will happen when you run a query?
3During startup the app crashes with a connection error. What steps do you take to handle that gracefully?

Follow-up Questions

Can you sketch the minimal code you would write?
What would you monitor to know the connection is healthy?
How would you test connection failures in CI?