troubleshooting of "DeprecationWarning Error"

[livetoworldlife]

if you get this error below when you run your app.js after part of the "Setting Up our Application",

DeprecationWarning: current Server Discovery and Monitoring engine is deprecated,
and will be removed in a future version. 
To use the new Server Discover and Monitoring engine, 
pass option { useUnifiedTopology: true } to the MongoClient constructor.
(Use `node --trace-deprecation ...` to show where the warning was created)

change the mongoOptions object in db.js file such as that below

const mongoOptions = {
  useNewUrlParser: true,
  useUnifiedTopology: true //  add this part to get ride of the error
};

I hope that is gonna help you.
Because it worked on my code...