Receiving "Cannot GET /" error when trying to connect using Node.js/Express

Question

Recently I started trying to get into Node.js/React and am using this tutorial https://auth0.com/blog/build-a-chat-app-with-react/.

However, even though I have followed the steps, I seem to be encountering an error. My page is displayed as "Cannot GET /" after hitting yarn start. I've found answers here NodeJS w/Express Error: Cannot GET / and here "Cannot GET /" with Connect on Node.js

Neither of these made sense to me though, as my code seems to differ from theirs slightly. I understand that the page doesnt know where to look for my GET request, and therefore what information to pull, but im not sure how to fix it.

The code in question, GET request at the end. Thanks.

// server.js
const express = require('express');
const path = require('path');
const bodyParser = require("body-parser");
const app = express();
const Pusher = require('pusher');


//initialize Pusher with your appId, key and secret
const pusher = new Pusher({
    appId: 'APP_ID',
    key: 'APP_KEY',
    secret: 'SECRET',
    cluster: 'YOUR CLUSTER',
    encrypted: true
});

// Body parser middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

// API route which the chat messages will be sent to
app.post('/message/send', (req, res) => {
  // 'private' is prefixed to indicate that this is a private channel
    pusher.trigger( 'private-reactchat', 'messages', {
        message: req.body.message,
        username: req.body.username
    });
    res.sendStatus(200);
});

// API route used by Pusher as a way of authenticating users
app.post('/pusher/auth', (req, res) => {
    const socketId = req.body.socket_id;
    const channel = req.body.channel_name;
    const auth = pusher.authenticate(socketId, channel);
    res.send(auth);
});

// Set port to be used by Node.js
app.set('port', (process.env.PORT || 5000));

app.listen(app.get('port'), function(req, res) {
    console.log('Node app is running on port', app.get('port'));
});

I'm guessing you hit this issue when you hit `localhost:5000`? — dcodesmith, Nov 13 '17 at 11:24
That's happening coz you're tryna hit a route that doesn't exist in the code. — dcodesmith, Nov 13 '17 at 11:42

score 1 · Answer 1 · answered Nov 13 '17 at 11:44

I assume that you are sending get request to localhost:5000 which isn't defined in your server so it can't send response back, because you are using react you want to send request on port on which react is running(3000 by default) so try accessing using localhost:3000 and it should work.

score 0 · Answer 2 · answered Nov 13 '17 at 11:44

You need to have the route available in the code. Try reading up on Express Basic Routing

Try the below and take it from there. I'm assuming that you're running on port 5000, if not, point to whatever port is set in process.env.PORT

app.get('/', function (req, res) {
  res.send('hello world');
})

Receiving "Cannot GET /" error when trying to connect using Node.js/Express

2 Answers2