I’ll introduce how to fix the error (node:42286) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect. that occurs in web applications with Express (Node.js) + Mongoose (MongoDB) configuration.

Solution: Add { useNewUrlParser: true } Option

• Official documentation: Mongoose v5.8.3: Connecting to MongoDB

(node:42286) DeprecationWarning Error Message

(node:42286) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.

Sample Code Before Fixing (node:42286) DeprecationWarning

const mongoose = require('mongoose');
mongoose.connect(process.env.MONGODB_URL);

Sample Code After Fixing (node:42286) DeprecationWarning

const mongoose = require('mongoose');
mongoose.connect(process.env.MONGODB_URL, { useNewUrlParser: true });

That’s all from the Gemba.