Connect to multiple database connects with MongoDB client.

multiple_db_connection.js

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

const { host } = config.get('dbConfig');
const mongoIp = process.env.NODE_ENV === 'production' ? host : 'localhost';

class Connection {
  static databases = {};

  static connectToMongo(dbName: string, options: object) {
    const url = `mongodb://${mongoIp}/${dbName}`;

    if (Object.keys(Connection.databases).length !== 0) {
      return Promise.resolve(Connection.databases);
    }

    return MongoClient.connect(url, options)
      .then((client: any) => {
        Connection.databases[dbName] = client.db(dbName);
        console.log(`Connected to ${dbName}`);
      }).catch(err => console.error(err));
  }
}

Connection.databases = {};

module.exports = { Connection };