mongodb-change-stream.js

const MongoClient = require('mongodb').MongoClient;
const url = "mongodb://mongo1:30001,mongo2:30002,mongo3:30003?replicaSet=my-rs";

MongoClient.connect(url, { useNewUrlParser: true })
    .then(client => {
        const db = client.db('test');
        const collection = db.collection('engineers');
        const changeStreamOptions = {
            fullDocument: 'updateLookup'
        };
        const changeStream = collection.watch(changeStreamOptions);
        changeStream.on('change', next => console.log(next));
    })
    .catch(err => console.log(err));

https://medium.com/@marchpig/mongodb-change-streams-baa78eaa82ed