Error: Cannot init client | mongo-connect express-session - mongodb

Question

I am getting error while trying to save session on mongodb. Here is my code..
const express = require("express");
const session = require("express-session");
const MongoStore = require("connect-mongo").default;
const app = express();
let sessionOptions = session({
secret: "JavaScript is cool",
store: MongoStore.create({ client: require("./db") }),
resave: false,
saveUninitialized: false,
cookie: { maxAge: 1000 * 60 * 60 * 24, httpOnly: true },
});
app.use(sessionOptions);
const router = require("./router");
app.use(express.urlencoded({ extended: false }));
app.use(express.json());
app.use(express.static("public"));
app.set("views", "views");
app.set("view engine", "ejs");
app.use("/", router);
module.exports = app;
and db.js
const dotenv = require("dotenv");
dotenv.config();
const mongodb = require("mongodb");
mongodb.connect(
process.env.CONNECTIONSTRING,
{ useNewUrlParser: true, useUnifiedTopology: true },
(err, client) => {
module.exports = client;
const app = require("./app");
app.listen(process.env.PORT);
}
);
And the error is here..
Assertion failed: You must provide either mongoUr|clientPromise in options
/home/irfan/Desktop/Brad_Sciff/Complex_App/node_modules/connect-mongo/build/main/lib/MongoStore.js:121
throw new Error('Cannot init client');
^
Error: Cannot init client
at new MongoStore (/home/irfan/Desktop/Brad_Sciff/Complex_App/node_modules/connect-mongo/build/main/lib/MongoStore.js:121:19)
at Function.create (/home/irfan/Desktop/Brad_Sciff/Complex_App/node_modules/connect-mongo/build/main/lib/MongoStore.js:137:16)
at Object.<anonymous> (/home/irfan/Desktop/Brad_Sciff/Complex_App/app.js:9:21)
at Module._compile (internal/modules/cjs/loader.js:778:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Module.require (internal/modules/cjs/loader.js:692:17)
at require (internal/modules/cjs/helpers.js:25:18)
I tried to change from const MongoStore = require("connect-mongo").default to const MongoStore = require("connect-mongo")(session)
But the error is showing..
const MongoStore = require("connect-mongo")(session);
^
TypeError: require(...) is not a function
at Object.<anonymous> (/home/irfan/Desktop/Brad_Sciff/Complex_App/app.js:4:44)
at Module._compile (internal/modules/cjs/loader.js:778:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Module.require (internal/modules/cjs/loader.js:692:17)
at require (internal/modules/cjs/helpers.js:25:18)
at mongodb.connect (/home/irfan/Desktop/Brad_Sciff/Complex_App/db.js:10:17)
at /home/irfan/Desktop/Brad_Sciff/Complex_App/node_modules/mongodb/lib/utils.js:693:5
Using Connect-mongo 4.2, express-session 1.17.1 express 4.17.1 mongodb 3.6.4
Don't know what I am missing.
Please help.
Thanks in Advance.
Irfan.

Answer 1

So it looks like connect-mongo has been updated recently. I came across this issue today as well and here's how I fixed it.
How it used to be:
const session = require('express-session');
const MongoStore = require('connect-mongo')(session);
app.use(
session({
...options
store: new MongoStore({ mongooseConnection: mongoose.connection }),
})
);
How it is now:
const session = require('express-session');
const MongoStore = require('connect-mongo').default;
app.use(
session({
store: MongoStore.create({ mongoUrl: process.env.MONGO_URI }),
...options
})
);
Try passing your connection string into mongoURL instead of client and see if that helps.
You can read more about connect-mongo in their docs.

Answer 2

the following is worked for me.
const mongoose = require("mongoose");
const session = require("express-session");
const MongoStore = require("connect-mongo");
const url = 'mongodb://localhost/mydb';
mongoose.connect(url, { useNewUrlParser: true, useCreateIndex: true,
useUnifiedTopology: true, useFindAndModify: true });
const connection = mongoose.connection;
connection.once('open', () => {
console.log("database connected successfully...");
}).catch(err => {
console.log("connection failed...");
});
// session store
let store = new MongoStore({
mongoUrl: url,
collection: "sessions"
});
// session config
app.use(session({
secret: process.env.COOKIE_SECRET,
resave: false,
store: store,
saveUninitialized: false,
cookie: { maxAge: 1000 * 60 * 60 * 24 }, // 24 hours
}));

Answer 3

what I did was to downgrade from mongodb version 4 to version 3. Hence, in your terminal, uninstall connect-mongo and reinstall lower version.
"npm uninstall connect-mongo"
"npm i connect-mongo#3"
this allows you to be able to pass in your session to the MongoStore.
"const path = require('path')
const express = require('express')
const mongoose = require ('mongoose')
const dotenv = require('dotenv')
const morgan = require('morgan')
const exphbs = require ('express-handlebars')
const passport = require('passport')
const session = require ('express-session')
const MongoStore = require('connect-mongo')(session)"

Answer 4

This is latest solution
add this lines
First
var session = require('express-session');
var MongoStore = require ('connect-mongo');
Second
app.use(session(
{
secret: '**something** like mysupersecret',
store: MongoStore.create({
mongoUrl: '**your url**like mongodb://localhost/test-app'}),
}));

Answer 5

There is an another npm package connect-mongodb-session,
https://www.npmjs.com/package/connect-mongodb-session
Install it and it should work.
const MongoDBStore = require('connect-mongodb-session')(session);

Answer 6

This worked for me,
const session = require('express-session');
const MongoStore = require('connect-mongo');
const dbUrl = process.env.DB_URL;
app.use(session({
secret: 'thisismysecret',
resave: false,
saveUninitialized: false,
store: MongoStore.create( {
mongoUrl: dbUrl,
touchAfter: 24 * 3600
}) }));