mongoConfigTesting.js

const mongoose = require('mongoose');
const { MongoMemoryServer } = require('mongodb-memory-server');

const mongoServer = new MongoMemoryServer();

mongoose.Promise = Promise;
mongoServer.getConnectionString().then((mongoUri) => {
    const mongooseOpts = {
        // options for mongoose 4.11.3 and above
        autoReconnect: true,
        reconnectTries: Number.MAX_VALUE,
        reconnectInterval: 1000,
        useNewUrlParser: true,
    };

    mongoose.connect(mongoUri, mongooseOpts);

    mongoose.connection.on('error', (e) => {
        if (e.message.code === 'ETIMEDOUT') {
            console.log(e);
            mongoose.connect(mongoUri, mongooseOpts);
        }
        console.log(e);
    });

    mongoose.connection.once('open', () => {
        console.log(`MongoDB successfully connected to ${mongoUri}`);
    });
});