MongoDB in node.js pattern

Question

I've been reading and searching about a good design related with mongodb driver.

Like here was said, there is no need to open/close connection , so I was trying to prevent boilerplate code using a dbLoader.js file like this (only using one database):

const { MongoClient } = require('mongodb')
const logger = require('./logger')
const configLoader = require('./configLoader')

module.exports = (async () => {
  const config = await configLoader()
  const client = await MongoClient.connect(config.db.uri)
  const db = client.db(config.db.dbName)
  logger.log('info', `Database ${config.db.dbName} loaded`)
  return db
})()

I wonder if there is some other approach that is better, and why. For example attaching it to app.locals (in express.js).

I'm not using mongoose and don't want to.

Answer 1

Consider using IOC containers such as https://github.com/inversify/InversifyJS or similar. For starters, you get the ability to mock the defined dependency for testing purposes (such as database connection) without hacky solutions, such as manual module mocking.