存储 MongoClient.connect()

Question

I work on a project whose code is divided into multiple js files. Until now, I 've been calling MongoClient.connect() multiple times (in each file using the db). That's when I got multiple deprecation warnings:

the options [servers] is not supported
the options [caseTranslate] is not supported
the options [dbName] is not supported
the options [srvHost] is not supported
the options [credentials] is not supported

I quickly found out it was related to all these open connections. Even though I can store MongoClient in a separate file, how can I store MongoClient.connect() , since a code that uses the database looks like that:

MongoClient.connect((err) => {
    // code here
});

and not like that:

MongoClient.connect()
// code here

Answer 1

EDIT: well, it seemed to work, but it looks like the exports of the file are equal to {} ...

---

The problem seems to be solved by putting the connection in a separate file (yes, I finally found out how to do it.).

mongoClient.js

require("dotenv").config();

// Declaring and configuring the mongoDB client
const { MongoClient } = require("mongodb");
const mongo = new MongoClient(process.env.MONGO_AUTH, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});

mongo.connect((err, result) => { // note the 'result':

    // result == mongo ✅

    // Exports the connection
    module.exports = result;

    // Logs out if the process is killed
    process.on("SIGINT", function () {
        mongo.close();
    });
});

Other file using the db

const mongo = require("./mongoClient")

const collection = mongo.db("niceDB").collection("coolCollection")
collection.findOne({fancy: "document"}); // It works!