When to close MongoDB database connection in Nodejs

Question

Working with Nodejs and MongoDB through Node MongoDB native driver. Need to retrieve some documents, and make modification, then save them right back. This is an example:

Answer 1

Here an extended example to the answer given by pkopac, since I had to figure out the rest of the details:

const client = new MongoClient(uri);
(async () => await client.connect())();

// use client to work with db
const find = async (dbName, collectionName) => {
  try {
    const collection = client.db(dbName).collection(collectionName);
    const result = await collection.find().toArray()
    return result;
  } catch (err) {
    console.error(err);
  }
}

const cleanup = (event) => { // SIGINT is sent for example when you Ctrl+C a running process from the command line.
  client.close(); // Close MongodDB Connection when Process ends
  process.exit(); // Exit with default success-code '0'.
}

process.on('SIGINT', cleanup);
process.on('SIGTERM', cleanup);

Here is a link to the difference between SIGINT and SIGTERM. I had to add the process.exit(), otherwise my node web-server didn't exit cleanly when doing Ctrl + C on the running process in command line.