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get method not displaying the data on browser and put showing error on postman

I'm creating an API with JS. While using the get method I'm not receiving the JSON data from the ./personal_data.js file. It's only displaying closed braces as response.
I'm attaching the code and output below. Any suggestions might be helpful.
const express = require('express');
const personal_data = require('./personal_data');
const app = express();
app.listen(3000, () => {
console.log('Listening on port 3000');
});
app.get('/', (req, res) => {
res.json({ Message: 'API is Working' }); // show messsage on serv
});
app.get('/personal_data', (req, res) => {
res.json(personal_data); // send employee json file
});
app.post('/personal_data',(req,res)=>{
res.send('post request')
})
json file with data
OUTPUT
Post man

Make sure you're exporting your data correctly. Use module.exports = ... instead of module.export = ... in your personal_data.js. Don't forget to restart your server once it's updated.
Check this sandbox where I show you the difference: CodeSandbox

Why does the webpage load forever if there is a 404?

I have an Express.js/Node.js website hosted with Heroku. If a file can't be found, the server is supposed to send a 404 error (like most websites do). But the error handlers in my code don't work properly. When the client requests a file that doesn't exist, the page will load...and load...and load...forever. How do I make the server stop loading when it detects the file can't be found?
This is the first section of my JavaScript:
var express = require('express'); // Express.js
var app = express();
var http = require('http');
var server = http.createServer(app);
var bodyParser = require('body-parser');
var postgres = require('pg'); // Postgres database
app.use(express.static('static', {
extensions: ['html']
}));
app.all('*', function (request, response, next) {
var redirectURL = request.query.redirect;
if (redirectURL != undefined) {
response.redirect(redirectURL);
}
});
app.get('/', function (request, response, next) {
response.redirect('/main/index');
});
And the following is my error handling middleware (it goes right after the previous part). The first one handles 400x error codes and the second one handles 500x error codes.
// Handle 404 error
app.use(function(request, response) {
response.status(400);
response.send("Error 404!");
});
// Handle 500 error
app.use(function(error, request, response, next) {
response.status(500);
response.send("Error 500!");
});
server.listen(process.env.PORT || 8080, function () {
console.log('Listening on port 8080!');
});

Call response.end() in your middleware, like so
// Handle 404 error
app.use(function(request, response) {
response.status(400);
response.send("Error 404!");
response.end();
});
This is how I check for errors in my app, one single middleware
app.use((err, req, res, next) => {
if (err.statusCode === 403) {
res.statusCode = 403;
var out = {
message: 'missing/invalid authorization: ' + err.message,
code: err.code,
statusCode: err.statusCode
};
res.end(JSON.stringify(out));
return;
}
next(err);
});
Check that your middleware actually gets called, console.log should be sufficient
If a middleware does not end the request, it must forward the request to the next middleware, so you need to call next(), the format of a middleware is
app.use((req, res, next) => {
//I'm not doing anything, forward the request
next();
});
app.use((req, res, next) => {
req.send('I ended the request');
//this middleware ended the request
}));

I had almost the same issue (in my case it was the page for HTTP 500 that was loading forever) and the problem was with another middleware that I have added myself and which was before the error handler middlewares and inside which I forgot to call next():
app.use(function(req: Request, res: Response, next: NextFunction) {
closeConnFromRequestStorage()
next(); // make sure to call to call next
});

Calling Express Route internally from inside NodeJS

I have an ExpressJS routing for my API and I want to call it from within NodeJS
var api = require('./routes/api')
app.use('/api', api);
and inside my ./routes/api.js file
var express = require('express');
var router = express.Router();
router.use('/update', require('./update'));
module.exports = router;
so if I want to call /api/update/something/:withParam from my front end its all find, but I need to call this from within another aspect of my NodeJS script without having to redefine the whole function again in 2nd location
I have tried using the HTTP module from inside but I just get a "ECONNREFUSED" error
http.get('/api/update/something/:withParam', function(res) {
console.log("Got response: " + res.statusCode);
res.resume();
}).on('error', function(e) {
console.log("Got error: " + e.message);
});
I understand the idea behind Express is to create routes, but how do I internally call them

The 'usual' or 'correct' way to handle this would be to have the function you want to call broken out by itself, detached from any route definitions. Perhaps in its own module, but not necessarily. Then just call it wherever you need it. Like so:
function updateSomething(thing) {
return myDb.save(thing);
}
// elsewhere:
router.put('/api/update/something/:withParam', function(req, res) {
updateSomething(req.params.withParam)
.then(function() { res.send(200, 'ok'); });
});
// another place:
function someOtherFunction() {
// other code...
updateSomething(...);
// ..
}

This is an easy way to do an internal redirect in Express 4:
The function that magic can do is: app._router.handle()
Testing: We make a request to home "/" and redirect it to otherPath "/other/path"
var app = express()
function otherPath(req, res, next) {
return res.send('ok')
}
function home(req, res, next) {
req.url = '/other/path'
/* Uncomment the next line if you want to change the method */
// req.method = 'POST'
return app._router.handle(req, res, next)
}
app.get('/other/path', otherPath)
app.get('/', home)

I've made a dedicated middleware for this : uest.
Available within req it allows you to req.uest another route (from a given route).
It forwards original cookies to subsequent requests, and keeps req.session in sync across requests, for ex:
app.post('/login', async (req, res, next) => {
const {username, password} = req.body
const {body: session} = await req.uest({
method: 'POST',
url: '/api/sessions',
body: {username, password}
}).catch(next)
console.log(`Welcome back ${session.user.firstname}!`
res.redirect('/profile')
})
It supports Promise, await and error-first callback.
See the README for more details

Separate your app and server files with the app being imported into the server file.
In the place you want to call your app internally, you can import you app as well as 'request' from 'supertest'. Then you can write
request(app).post('/someroute').send({
id: 'ecf8d501-5abe-46a9-984e-e081ac925def',
etc....
});`

This is another way.
const app = require('express')()
const axios = require('axios')
const log = console.log
const PORT = 3000
const URL = 'http://localhost:' + PORT
const apiPath = (path) => URL + path
app.get('/a', (req, res) => {
res.json('yoy')
})
app.get('/b', async (req, res) => {
let a = await axios.get(apiPath('/a'))
res.json(a.data)
})
app.listen(PORT)

Make http request within node js routes

I am building a slideshow that pulls pictures with a certain tag on instagram. The Instagram API requires me to make a call to their auth URL to receive an access token. Using node js and express I built out the backend like so:
var express = require('express');
var app = express();
app.use(express.static('public'));
app.listen(4000,function(){
console.log("Listening to app on localhost 4000");
})
app.get('/',function(req,res){
1. make call to Instagram authorization URL:
https://api.instagram.com/oauth/authorize/?client_id=CLIENT-ID&redirect_uri=http://localhost:4000&response_type=code
2. URL will be redirected with access code parameter
3. Use access code to make POST request to receive access token to be able to make GET requests.
})
My question is how do I make a request to visit that url within NodeJS/Express? Is it just a normal http.request()?
I don't want to user to go through the redirect process so that's why I want to put it in Node. I'm following these instructions https://www.instagram.com/developer/authentication/

You can do a redirect or use a npm library like instagram-node-lib
var express = require('express');
var request = require('request');
var app = express();
app.use(express.static('public'));
app.listen(4000, function () {
console.log("Listening to app on localhost 4000");
})
app.get('/', function (req, res) {
res.redirect('https://api.instagram.com/oauth/authorize/?client_id=CLIENT-ID&redirect_uri=http://localhost:4000/mycallback&response_type=code')
})
app.get('/mycallback', function (req, res) {
//handle token retrieval here
//do a get request as per the instagram documentation using the code sent back
var code = req.query.code
var url = 'https://api.instagram.com/oauth/access_token'
var options = {
method: 'post',
body: {
client_secret: 'CLIENT_SECRET',
grant_type: 'authorization_code',
redirect_uri: 'AUTHORIZATION_REDIRECT_URI',
code: code
},
json: true,
url: url
}
request(options, function (err, res, body) {
//body should look something like this
// {
// "access_token": "fb2e77d.47a0479900504cb3ab4a1f626d174d2d",
// "user": {
// "id": "1574083",
// "username": "snoopdogg",
// "full_name": "Snoop Dogg",
// "profile_picture": "..."
// }
// }
})
})
You will always require the redirect as that is how oAuth works. The user enters a password on the Instagram site. A code is sent back to your server via a callback url (redirect). You then use that code to retrieve the user token. You can then use the authorization token for subsequent calls.

Client side javascript doesn't find my url

I would like to develop a client server side with nodejs and javascript/jquery but I am stuck.
I have a big form, user submits and data are send to /getData url and that works perfectly. But my problem now it's when I want to get those data from /getData to my client side.
This is my client file:
var client = {};
client.start = function () {
client.getData();
};
client.cb_get = function () {
var data={};
if (this.readyState == 4 && this.status == 200) {
data= JSON.parse(this.responseText);
alert("We get the data" + JSON.stringify(data, null, 4));
client.chart(data);
} else {
alert("Sorry this page is not allow without processing any form");
}
};
client.get = function(req, cb) {
var xhr = new XMLHttpRequest();
xhr.open("GET", req, true);
xhr.onreadystatechange = cb;
xhr.send();
};
client.getData= function () {
var req="http://localhost:3000/getData";
client.get(req,client.cb_get);
};
client.chart= function (data) {
//Display data as charts using jquery in an other html page.
};
window.onload = setTimeout(client.start, 1);
HTMLElement.prototype.has_class = function (c)
{
return this.className.indexOf(c) >= 0;
};
But I have a 404 error all the time and I don't know why.
my server file :
var express = require('express')
bodyParser =require("body-parser");
routes= require('./router.js');
var app= express();
app.use(express.static(__dirname + '/'));
//Here we are configuring express to use body-parser as middle-ware.
app.use(bodyParser.urlencoded({ extended: false }));
//define our routes
app.get('/', routes.index); //open home page
app.get('/simulation', routes.simulation);
app.get('/chartData', routes.chartData);
app.post('/getData', routes.getData);
//In case of malicious attacks or mistyped URLs
app.all('*', function(req, res){
res.send(404);
})
var server = app.listen(3000, function () {
var host = server.address().address
var port = server.address().port
console.log('Example app listening at http://%s:%s', host, port)
})
my router file:
module.exports.index= function(req, res){
fs.readFile('index.html', function(err, page) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(page);
res.end();
});
};
module.exports.simulation= function(req, res){
fs.readFile('simulation.html', function(err, page) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(page);
res.end();
});
};
module.exports.chartData= function(req,res) {
fs.readFile('chartPage.html', function(err, page) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(page);
res.end();
});
};
module.exports.getData= function(req,res) {
var data= {};
data= req.body;
res.send(JSON.stringify(data, null, 4));
console.log(req.body);
};
So where I am wrong?
Moreover, when I submit, my /getdata page opens (normal due to action= /getData specified in my form tag) but I want to open directly my html page with charts. How can I do that?
Sorry guys for my long post, but I really need help.

Your ajax request does
xhr.open("GET", "http://localhost:3000/getData", true);
your route listens for
app.post('/getData', routes.getData);
notice how you send a GET request and listen for a POST request, it's not the same thing, so you end up in the 404 route instead.
You either have to change the ajax request, and send a POST request, or the route and listen for a GET request.