TypeError: Router.use() requires middleware function but got a Object

Question

There have been some middleware changes on the new version of express and I have made some changes in my code around some of the other posts on this issue but I can't get anything to stick.

We had it working before hand but I can't remember what the change was.

throw new TypeError('Router.use() requires middleware function but got a ^ TypeError: Router.use() requires middleware function but got a Object

node ./bin/www js-bson: Failed to load c++ bson extension, using pure JS version js-bson: Failed to load c++ bson extension, using pure JS version

/Users/datis/Documents/bb-dashboard/node_modules/express/lib/router/index.js:438 throw new TypeError('Router.use() requires middleware function but got a ^ TypeError: Router.use() requires middleware function but got a Object at /Users/datis/Documents/bb-dashboard/node_modules/express/lib/router/index.js:438:13 at Array.forEach (native) at Function.use (/Users/datis/Documents/bb-dashboard/node_modules/express/lib/router/index.js:436:13) at /Users/datis/Documents/bb-dashboard/node_modules/express/lib/application.js:188:21 at Array.forEach (native) at Function.use (/Users/datis/Documents/bb-dashboard/node_modules/express/lib/application.js:185:7) at Object.<anonymous> (/Users/datis/Documents/bb-dashboard/app.js:46:5) at Module._compile (module.js:456:26) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32)

app.js

var express = require('express'); var path = require('path'); var favicon = require('serve-favicon'); var logger = require('morgan'); var cookieParser = require('cookie-parser'); var bodyParser = require('body-parser'); var mongoose = require('mongoose'); var session = require('express-session'); var MongoClient = require('mongodb').MongoClient; var routes = require('./routes/index'); var users = require('./routes/users'); var Users = require('./models/user'); var Items = require('./models/item'); var Store = require('./models/store'); var StoreItem = require('./models/storeitem'); var app = express(); //set mongo db connection var db = mongoose.connection; MongoClient.connect("mongodb://localhost:27017/test", function(err, db) { if(!err) { console.log("We are connected"); } }); // var MONGOHQ_URL="mongodb://localhost:27017/test" // view engine setup app.set('views', path.join(__dirname, 'views')); app.set('view engine', 'ejs'); // uncomment after placing your favicon in /public //app.use(favicon(__dirname + '/public/favicon.ico')); app.use(logger('dev')); app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended: false })); app.use(cookieParser()); app.use(session({ secret: 'something', resave: true, saveUninitialized: true })); app.use('/', routes); app.use('/users', users); app.use(express.static(path.join(__dirname, 'public'))); // catch 404 and forward to error handler // app.use(function(req, res, next) { // var err = new Error('Not Found'); // err.status = 404; // next(err); // }); // Make our db accessible to our router app.use(function(req, res, next){ req.db = db; next(); }); // error handlers // development error handler // will print stacktrace if (app.get('env') === 'development') { app.use(function(err, req, res, next) { res.status(err.status || 500); res.render('error', { message: err.message, error: err }); }); } // production error handler // no stacktraces leaked to user app.use(function(err, req, res, next) { res.status(err.status || 500); res.render('error', { message: err.message, error: {} }); }); module.exports = app;

It appears the answer to this question has changed for versioning reasons. Thanks to Nik

UNDEFINED! someone (probably me) had commented out module.exports on the index page? Anyway I uncommented the line and added a var routes and at least the server is starting up. — Datise
– Datise, Commented Dec 14, 2014 at 3:27

Anirudh · Accepted Answer · 2015-02-07 08:10:34Z

1548

In any one of your js pages you are missing

module.exports = router;

Check and verify all your JS pages

answered Feb 7, 2015 at 8:10

Anirudh

15.8k2 gold badges17 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

10 Comments

sac Dahal Over a year ago

@Anirudh Mind describing the reason for the error as well

Adil Over a year ago

@Anirudh, thanks it was helpful but how to export router here in ES6? simple export {router} also gives that error

Anirudh Over a year ago

@adi stackoverflow.com/questions/38550979/… here you go :)

AndrewLeonardi Over a year ago

Worth noting this is typically at the very end of you js page

Muhammad Umer Over a year ago

well i was missing an s at end :|

|

Parikshit Hooda · Accepted Answer · 2018-04-24 17:34:10Z

151

Simple solution if your are using express and doing

const router = express.Router();

make sure to

module.exports = router ;

at the end of your page

answered Apr 24, 2018 at 17:34

Parikshit Hooda

1,6011 gold badge10 silver badges5 bronze badges

2 Comments

TheRealChx101 Over a year ago

Doesn't this overwrite other properties under the exports? I'm exporting multiple.

user1063287 Over a year ago

is export default router the ES6 equivalent of module.exports = router?

S. Hesam · Accepted Answer · 2022-01-08 11:22:25Z

62

In my case, I wasn't exporting the module. module.exports = router;

edited Jan 8, 2022 at 11:22

S. Hesam

7,1616 gold badges46 silver badges66 bronze badges

answered Jul 14, 2020 at 17:49

Usama Tahir

1,36312 silver badges14 bronze badges

3 Comments

Akin Okegbile Over a year ago

How does this differ from the two answers above saying module.exports = router;

kiddo Over a year ago

same in my case, thank you @UsamaTahir . I was doing this stupid, 3rd grade scholl, mistake :)

Sandeep Amarnath Over a year ago

I was doing module.export instead of module.exports. Thanks!

Striped · Accepted Answer · 2020-11-07 14:13:44Z

36

If your are using express above 2.x, you have to declare app.router like below code. Please try to replace your code

app.use('/', routes);

with

app.use(app.router); routes.initialize(app);

Please click here to get more details about app.router

Note:

app.router is depreciated in express 3.0+. If you are using express 3.0+, refer to Anirudh's answer below.

edited Nov 7, 2020 at 14:13

Striped

2,5443 gold badges27 silver badges33 bronze badges

answered Dec 14, 2014 at 3:42

Rahul Radhakrishnan

8411 gold badge7 silver badges18 bronze badges

4 Comments

Nik Over a year ago

Just a note that app.router has been deprecated: github.com/strongloop/express/wiki/Migrating-from-3.x-to-4.x

geeky_monster Over a year ago

The most likely fix for most such cases is @Anirudh's answer below.

rotarydial Over a year ago

I found this answer to be misleading. The better answer is by @Anirudh below.

RaneWrites Over a year ago

The answer below is better, as others have mentioned.

Anish Jain · Accepted Answer · 2020-11-17 08:10:15Z

You are missing router exports module and that is the reason why this error is present.

use module.exports = router; and that would work

Rahul More · Accepted Answer · 2022-01-22 08:53:53Z

22

You just have to export your router using module.exports = router;

answered Jan 22, 2022 at 8:53

Rahul More

5426 silver badges10 bronze badges

Comments

K23raj · Accepted Answer · 2019-07-03 17:31:41Z

check your routes.js file

example my routes.js

 const express = require('express') const router = express.Router() const usersController = require('../app/controllers/usersController') const autheticateuser = require('../app/middlewares/authentication') router.post('/users/login', autheticateuser, usersController.login) router.post('/users/register', autheticateuser, usersController.register)

check end of routes.js

module.exports = router

if not there add and module.exports = router run again

If your Error is : "TypeError: Route.post() or Route.get() requires middleware function but got a Object"

goto controller.js (i.e., usersController) and check all the function names you might misspelled , or you given in function routes file but missed in contollers

const User = require('../models/user') const express = require('express') const router = express.Router() module.exports.register = (req, res) => { const data = req.body const user = new User(data) user.save() .then((user) => { res.send(user) }) .catch((err) => { res.json(err) }) }

in routes.js i given two routes but in controllers i missed to define route for

router.post('/users/login')

this will make error **

"TypeError: route.post() requires middleware function but got a Object"

**

antzshrek · Accepted Answer · 2018-04-27 18:03:06Z

I was getting the same error message but had a different issue. Posting for others that are stuck on same.

I ported the get, post, put, delete functions to new router file while refactoring, and forgot to edit the paths. Example:

Incorrect:

//server.js app.use('/blog-posts', blogPostsRouter); //routers/blogPostsRouter.js router.get('/blog-posts', (req, res) => { res.json(BlogPosts.get()); });

Correct:

//server.js app.use('/blog-posts', blogPostsRouter); //routers/blogPostsRouter.js router.get('/', (req, res) => { res.json(BlogPosts.get()); });

Took a while to spot, as the error had me checking syntax where I might have been wrapping an argument in an object or where I missed the module.exports = router;

I had a similar error when I referenced a route that didn't exist

IronmanX46 · Accepted Answer · 2021-07-06 06:18:58Z

I got this error because I had used a series of files like this:

app.use('/api/someName1', someName1); app.use('/api/someName2', someName2); ... app.use('/api/someNameN', someNameN);

The issue was although I had properly declared it, one of the files was still empty. Just leaving it here in case someone else too does this mistake. To stop wasting time on some of the other solutions since it was the same error message that gets displayed for all.

Happy hacking!

oms · Accepted Answer · 2022-12-06 06:22:49Z

For me, following worked.

instead of this

app.use('/', routes);

use

app.use('/', () => routes);

or

app.use('/', function(){routes});

Piyush Aggarwal · Accepted Answer · 2023-10-15 20:03:39Z

I am slowly converting my JavaScript project to TypeScript and I got the same error. So, it is a mess of commonjs and module type systems.

I got the error because I was not using .default to import the router.

Router file

import { Router } from 'express' const router = Router() router.get('/', (req, res) => { res.json({ success: true }) }) export default router

File where used it

app.use("/api/my-route", require("./Routes/NewEmail").default)

None other answers had this particular case so I thought of actually posting.

antzshrek · Accepted Answer · 2018-04-27 18:12:26Z

I had this error and solution help which was posted by Anirudh. I built a template for express routing and forgot about this nuance - glad it was an easy fix.

I wanted to give a little clarification to his answer on where to put this code by explaining my file structure.

My typical file structure is as follows:

/lib /routes

---index.js (controls the main navigation)

/page-one /page-two ---index.js

(each file [in my case the index.js within page-two, although page-one would have an index.js too]- for each page - that uses app.METHOD or router.METHOD needs to have module.exports = router; at the end)

If someone wants I will post a link to github template that implements express routing using best practices. let me know

Thanks Anirudh!!! for the great answer.

Ralf Stubner · Accepted Answer · 2018-07-15 20:21:20Z

Check your all these file:

var users = require('./routes/users'); var Users = require('./models/user'); var Items = require('./models/item');

Save properly, In my case, one file was missed and throwing the same error

Wasit Shafi · Accepted Answer · 2021-12-25 02:37:53Z

In my case I have written app.use('view engine', 'ejs'); instead of app.set('view engine', 'ejs'); to set ejs as the view engine.

Esteban · Accepted Answer · 2022-08-10 22:12:15Z

In my case, the problem was that I was requiring the wrong file to pass as a middleware ( app.use(nameOfFile) ). Once I imported the correct one, the error went away.

first · Accepted Answer · 2022-10-31 14:52:45Z

In my case I was exporting the middleware function as exports.function_name, changing this to a call back function and doing module.exports = function_name; solved the issue for me.

Moreover in your routes you could do,

const function_name = require('./middlewares/middleware_file_name'); router.use('/protected_route', function_name);

Amin · Accepted Answer · 2022-12-20 08:08:07Z

0

In my case I mistakenly read route file without using require:|

answered Dec 20, 2022 at 8:08

Amin

313 bronze badges

1 Comment

Insane Skull Over a year ago

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review

denisdolmatov · Accepted Answer · 2024-01-09 03:07:36Z

Maybe somebody... My case its from import and depend on setttings config

Sample: from: const nameModule = required('path'); change on: import nameModule from 'path'

Collectives™ on Stack Overflow

TypeError: Router.use() requires middleware function but got a Object

18 Answers 18

10 Comments

2 Comments

3 Comments

Note:

4 Comments

Comments

Comments

1 Comment

1 Comment

Comments

Comments

Router file

File where used it

Comments

Comments

Comments

Comments

Comments

Comments

1 Comment

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

18 Answers 18

10 Comments

2 Comments

3 Comments

Note:

4 Comments

Comments

Comments

1 Comment

1 Comment

Comments

Comments

Router file

File where used it

Comments

Comments

Comments

Comments

Comments

Comments

1 Comment

Comments

Linked

Related