A neat way to interact with mongoclient, without caring too many proxies.

db.js

const MongoClient = require('mongodb').MongoClient;

const DB_NAME = 'mydb';
const MONGO_URL = process.env.MONGO_URL;

const dbPromise = MongoClient.connect(
  MONGO_URL,
  { useNewUrlParser: true },
).then(client => client.db(DB_NAME));

// if anything went wrong connecting db
dbPromise.catch(e => {
  console.error(e);
  console.error('Cannot connect to mongodb...');
  process.exit(1);
});

module.exports = new Proxy({}, {
  get(target, collectionName) {
    return new Proxy({}, {
      get(target, methodName) {
        return async (...args) => {
          const collection = await dbPromise.then(db => db.collection(collectionName));
          return collection[methodName](...args);
        };
      },
    });
  },
});

The main advantage of this script is you won't need to worry about all the intermediate promises but only focus on the actual operation u wanna perform
Example usage:

Without this script:

MongoClient.connect('some mongo url').then(client => {
  client.db('some db name').then(db => {
    db.collection('some collection name').then(collection => {
      collection.insertOne({...});
    });
  });
});

With this script:

const db = require('./db.js');

db.members.insertOne({
  name: 'Jason Yu'
}).then(...);