Cannot read property 'push' of undefined in node_modules - node.js

Question

while running my first MEAN stack application i am getting this error:
\contactlist\node_modules\express\lib\router\index.js:502
this.stack.push(layer);
^
TypeError: Cannot read property 'push' of undefined
at Function.route (C:\Users\Mahima Kaushik\Desktop\contactlist\node_modules\express\lib\router\index.js:502:14)
at Function.proto. [as post] (C:\Users\Mahima Kaushik\Desktop\contactlist\node_modules\express\lib\router\index.js:509:22)
at Object. (C:\Users\Mahima Kaushik\Desktop\contactlist\routes\route.js:11:8)
at Module._compile (internal/modules/cjs/loader.js:1251:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1272:10)
at Module.load (internal/modules/cjs/loader.js:1100:32)
at Function.Module._load (internal/modules/cjs/loader.js:962:14)
at Module.require (internal/modules/cjs/loader.js:1140:19)
at require (internal/modules/cjs/helpers.js:75:18)
at Object. (C:\Users\Mahima Kaushik\Desktop\contactlist\app.js:9:15)
at Module._compile (internal/modules/cjs/loader.js:1251:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1272:10)
at Module.load (internal/modules/cjs/loader.js:1100:32)
at Function.Module._load (internal/modules/cjs/loader.js:962:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
at internal/main/run_main_module.js:17:47
contactlist/app.js
var express = require('express');
var mongoos = require('mongoose');
var bodyparser = require('body-parser');
var cors = require('cors');
var path = require('path');
var app = express();
const route = require('./routes/route');
//connect to mongodb
mongoos.Mongoose.connect('mongodb://localhost:27017/contactlist');
//on connection
Mongoose.connection.on('connected',()=>{
console.log('connected to database mongodb #2717');
});
Mongoose.connection.on('error',(err)=>{
if(err)
{
console.log('error in database connection:'+err);
}
});
//port number
const port = 3000
//adding middleware -cors
app.use(cors());
//boday-parser
app.use(bodyparser.json());
//static files
app.use(express.static(path.join(__dirname,'public')));
//add routes
app.use('/api',route);
//testing
app.get('/',(req,res)=>{
res.send('contactlist');
});
app.listen(port,()=>{
console.log('server started at port:'+port);
});
contactlist/routes/route.js
const { Router } = require('express');
const express = require("express");
const router = express.Router();
//retrieving contacts
router.get('/contacts',(req,res,next) =>{
res.send('retrieving the contact list');
});
//add contacts
Router.post('/contact',(req , res, next)=>{
//logic
});
//delete contacts
Router.delete('/contact/:id',(req , res, next)=>{
//logic
});
module.exports = router;

Answer 1

You didn't create route correctly. The .get, .post and .delete are instance methods of Router instance, NOT static method. For more info, see Routing
routes/route.js should be:
const { Router } = require('express');
const router = Router();
//retrieving contacts
router.get('/contacts', (req, res, next) => {
res.send('retrieving the contact list');
});
//add contacts
router.post('/contact', (req, res, next) => {
//logic
});
//delete contacts
router.delete('/contact/:id', (req, res, next) => {
//logic
});
module.exports = router;