express - Keep getting this error: Error: Route.post() requires callback functions but got a [object Undefined] -

i trying set react express application mongo db database. in preliminary stages , keep coming across error:

 error: route.post() requires callback functions got [object undefined] 

here app.js

const express = require('express'); // const http = require('http'); const bodyparser = require('body-parser'); const morgan = require('morgan'); const app = express(); const mongoose = require('mongoose');  mongoose.promise = global.promise;   //db  , name auth  mongoose.connect('mongodb://localhost/auth', {     usemongoclient: true,     /* other options */   }); // app setup  //server setup  const port = process.env.port || 4000 // const server = http.createserver(app); app.listen(port); console.log(`sever listening on ${port}`)  const authroutes = require('./routes/auth_routes'); app.use('/',authroutes);  

my routes right here. testing see if there correct connection.

const authcontroller = '../controllers/auth_controller'; const express = require('express'); const authroutes = express.router();       authroutes.post('/',authcontroller.signup)    module.exports = authroutes; 

my controller listed below:

const authcontroller = {};  authcontroller.signup = function(req,res,next) {     console.log('here');     res.json({         user: "doesnt matter",         data: 'put user profile on route'       }); }  module.exports = authcontroller; 

not sure if mongo problem since first time using it, connection database works robo 3t check whats in database , user schema there. if comment out 1 route in routes page, errors go away.

i believe problem here:

const authcontroller = '../controllers/auth_controller';  authroutes.post('/',authcontroller.signup) 

note authcontroller string. i'm guessing intended:

const authcontroller = require('../controllers/auth_controller');