Develop Reference

What does this error mean and how would I fix it: throw new TypeError('app.use() requires a middleware function')?

I am trying to create a login page and sign up page, my app.js gives me this error, I think it is the last line of this code. I can send you the other components(files) for this express app. I cannot understand what is causing this error.
const express = require('express');
const mongoose = require('mongoose');
// Routes
const authRoutes = require('./routes/authRoutes');
const app = express();
// middleware
app.use(express.static('public'));
app.use((err, req, res, next) => {
res.locals.error = err;
res.status(err.status);
res.render('error');
});
// view engine
app.set('view engine', 'ejs');
// database connection
const dbURI = '<database, username and password>';
mongoose.connect(dbURI, { useNewUrlParser: true, useUnifiedTopology: true, useCreateIndex:true })
.then((result) => app.listen(3000))
.catch((err) => console.log(err));
// routes
app.get('/', (req, res) => res.render('home'));
app.get('/smoothies', (req, res) => res.render('smoothies'));
app.use(authRoutes);
authRoutes.js
const { Router } = require('express')
const authController = require('./authController.js')
const router = Router();
router.get('/signup', authController.signup_get);
router.get('/signup', authController.signup_post);
router.get('/login', authController.login_get);
router.get('/login', authController.login_post);
module.export = router;
authController.js
module.exports.signup_get = (req, res) => {
res.render('signup');
}
module.exports.login_get = (req, res) => {
res.render('login');
}
module.exports.signup_post = (req, res) => {
res.send('signup');
}
module.exports.login_post = (req, res) => {
res.send('login');
}

You are exporting incorrectly in authRoutes.js.
Change this:
module.export = router;
to this:
module.exports = router;
FYI, a little debugging on your own by simply doing a console.log(authRoutes) should have been able to show you where to look for the problem. If you get an error when you attempt to use authRoutes, you look at what it is and where it came from to see why it's not working. This is basic debugging and there is an expectation that you've done basic debugging before you post your question here.

Connecting to MySQL Database from React?

I've been having problems with connecting to a database. It is a remote database and no matter what I do, it just doesn't work! I've searched all around to no avail. I'm using React for doing so. I just want to make a simple connection and be able to run some queries. Here's the code:
db.js component:
const mysql = require('mysql');
const db = mysql.createConnection({
/*THE VALUES BELOW ARE NOT THE ONES I HAVE TO USE*/
host: '11.111.11.11',
user: 'username',
password: 'password',
port: 'port',
database: 'database'
});
module.exports = db;
server.js in my backend folder:
const express = require('express');
const db = require('./config/db');
const cors = require('cors');
const app = express();
const PORT = 3002;
app.use(cors());
app.use(express.json());
//ROUTE
app.get("/db", (req, res) => {
db.query("SELECT * FROM users", (err, result) => {
if(err) {
console.log(err);
} else {
res.send(result);
console.log(result);
console.log('Connected!');
}
});
});
app.listen(PORT, ()=>{
console.log(`Server is running on http://localhost/${PORT}/`);
});
I'm not getting anything from it, not even the logged info I asked for in the console.log()
Thanks for the help, in advance.

You have just created the connection, however you need also use the connect function to connect to your database. So you need to add a line in your server.js, (I have put a comment near the line that you missed to write.
const db = require('./config/db');
const cors = require('cors');
const app = express();
const PORT = 3002;
app.use(cors());
app.use(express.json());
db.connect(); // you missed this line
//ROUTE
app.get("/db", (req, res) => {
db.query("SELECT * FROM users", (err, result) => {
if(err) {
console.log(err);
} else {
res.send(result);
console.log(result);
console.log('Connected!');
}
});
});
app.listen(PORT, ()=>{
console.log(`Server is running on http://localhost/${PORT}/`);
});
I think you can also do this in db.js before exporting db.

Cannot read fetch data on express server

On the client side, I have an application based on threejs an d javascript. I want to send data to the server written in express using fetch. Unfortunately, the server does not receive the data and the browser also gives an error:
Uncaught (in promise) TypeError: NetworkError when attempting to fetch resource.
Application:
this.username = prompt("Username:");
const body = JSON.stringify({ username: this.username });
fetch("http://localhost:3000/addUser", { method: "POST", body })
.then((response) => response.json())
.then(
(data) => (
console.log(data), (this.aktualny_album_piosenki = data.files)
)
);
Server:
var express = require("express")
var app = express()
const PORT = 3000;
var path = require("path");
app.use(express.static('dist'));
var bodyParser = require("body-parser");
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
var cors = require('cors');
app.use(cors());
app.post("/addUser", function (req, res) {
console.log(req.body)
})

I might be wrong but maybe try... (very bottom of your main server file)
app.listen((PORT) => {
console.log(`app is listening on port ${PORT}`);
})
is required maybe? I have this chunk of code in every project of my own so maybe that could fix the server not recognizing the api request
express documentation on app listen
heres what I use typically... this is a boilerplate for every one of my projects
const express = require("express");
const app = express();
const connectDB = require("./config/db.js");
const router = express.Router();
const config = require("config");
// init middleware
const bodyParser = require('body-parser');
const cors = require("cors");
const mongoDB = require("./config/db.js");
const path = require("path");
const http = require("http");
const server = http.createServer(app);
const io = require('socket.io')(server, {
cors: {
origin: '*',
}
});
const xss = require('xss-clean');
const helmet = require("helmet");
const mongoSanitize = require('express-mongo-sanitize');
const rateLimit = require("express-rate-limit");
const PORT = process.env.PORT || 5000;
mongoDB();
app.options('*', cors());
app.use('*', cors());
app.use(cors());
const limitSize = (fn) => {
return (req, res, next) => {
if (req.path === '/upload/profile/pic/video') {
fn(req, res, next);
} else {
next();
}
}
}
const limiter = rateLimit({
max: 100,// max requests
windowMs: 60 * 60 * 1000 * 1000, // remove the last 1000 for production
message: 'Too many requests' // message to send
});
app.use(xss());
app.use(helmet());
app.use(mongoSanitize());
app.use(limiter);
// app.use routes go here... e.g. app.use("/login", require("./routes/file.js");
app.get('*', function(req, res) {
res.sendFile(__dirname, './client/public/index.html')
})
app.get('*', cors(), function(_, res) {
res.sendFile(__dirname, './client/build/index.html'), function(err) {
if (err) {
res.status(500).send(err)
};
};
});
app.get('/*', cors(), function(_, res) {
res.sendFile(__dirname, './client/build/index.html'), function(err) {
if (err) {
res.status(500).send(err)
};
};
});
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", '*');
res.header("Access-Control-Allow-Credentials", true);
res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
res.header("Access-Control-Allow-Headers", 'Origin,X-Requested-With,Content-Type,Accept,content-type,application/json');
next();
});
if (process.env.NODE_ENV === "production") {
// Express will serve up production files
app.use(express.static("client/build"));
// serve up index.html file if it doenst recognize the route
app.get('*', cors(), function(_, res) {
res.sendFile(__dirname, './client/build/index.html'), function(err) {
if (err) {
res.status(500).send(err)
}
}
})
app.get('/*', cors(), function(_, res) {
res.sendFile(path.join(__dirname, './client/build/index.html'), function(err) {
if (err) {
res.status(500).send(err)
}
})
})
};
io.on("connection", socket => {
console.log("New client connected");
socket.on("disconnect", () => console.log("Client disconnected"));
});
server.listen(PORT, () => {
console.log(`Server listening on port ${PORT}!`);
});
client-side fetch request looks good to me its prob a server/express.JS thing but like i said i may be wrong but worth trying

Cannot get "/tinder/cards" route but getting "/" route

This below code is my first react application. After running server.js. After entering "http://localhost:8001/" I got HELLO!!. I expected after entering "http://localhost:8001/tinder/cards" url on chrome and postman too I get following error.
error message: "Cannot GET /tinder/cards".
this is my server.js file.
import mongoose from 'mongoose'
import Cors from 'cors'
import Cards from './dbCards.js'
// App Config
const app = express()
const port = process.env.PORT || 8001
const connection_url = 'mongodb+srv://admin:0tRkopC1DKm4ym4V#cluster0.iw73w.mongodb.net/tinderDB?retryWrites=true&w=majority'
// Middlewares
app.use(express.json())
app.use(Cors())
app.use('/',router);
// DB Config
mongoose.connect(connection_url, {
useNewUrlParser: true,
useCreateIndex: true,
useUnifiedTopology: true
})
// API Endpoints
app.get("/", (req, res) => res.status(200).send("HELLO!!"))
app.get("/hello", (req, res) => res.status(200).send("Oooooooo!!"))
app.post("/tinder/cards", (req, res) => {
const dbCard = req.body
Cards.create(dbCard, (err, data) => {
if(err) {
res.status(500).send(err)
} else {
res.status(201).send(data)
}
})
})
app.get("/tinder/cards", (req, res) => {
Cards.find((err, data) => {
if(err) {
res.status(500).send(err)
} else {
res.status(200).send(data)
}
})
})
// Listener
app.listen(port, () => console.log(`listening on location: ${port}`)) ```

try this in your app.get('/tinder/cards') section:
// Doing it the Asynchronous way
app.get('/tinder/cards', async (req, res) => {
try { // Trying for getting the cards
const allCards = await Cards.find(); // Getting the cards
res.status(200).send(allCards); // Sending the cards
} catch (error) { // Catching the error
res.status(500).send(error); // Sending the error
}
});

Try to replace cards with card in the URL. Have a look at the image for the same.

Trying to findById but server is not return proper status response

Attempting to use Axios.get method to get ':id'
S̶e̶r̶v̶e̶r̶ ̶i̶s̶ ̶r̶e̶s̶p̶o̶n̶d̶i̶n̶g̶ ̶w̶i̶t̶h̶ ̶a̶ ̶4̶0̶4̶
Currently I am unable to set the state of the component. I get an empty object
I've tried adjusting the controller parameters but cannot seem to figure it out
loadProfile() {
axios.get('http://localhost:3000/api/companies/' + this.props.match.params.id)
.then(res => {
if (!res) {
console.log("404 error, axios cannot get response");
} else {
console.log(res.data);
this.setState({ company: res.data });
}
});
express api route
companyRoutes.route('/:id').get(company_controller.company_id_get);
express controller
exports.company_id_get = (req, res) => {
const id = req.params.id;
Company.findById( id, (company, err) => {
if(err) {
console.log("404 error", err);
}
else {
res.json(company);
}
})
}
Server Side Code
'use strict';
const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
const cors = require('cors')
const passport = require('passport');
const app = express();
const users = require('./routes/api/users');
const companyRoute = require('./routes/api/companies');
app.use(express.static("static"));
//Bodyparser middleware
app.use(cors());
app.use(
bodyParser.urlencoded({
extended: false
})
);
app.use(bodyParser.json());
// DB configuration
const db = require("./config.scripts/mongoKey").mongoURI;
// Connect to MonngoDB
mongoose.connect(
db, { useNewUrlParser: true }
)
.then((db) => console.log('MongoDB succesfully connected'))
.catch(err => console.log(err));
//Passport middleware
app.use(passport.initialize());
//Passport config
require('./config.scripts/passport.js')(passport);
//Routes
app.use('/api/users', users);
app.use('/api/companies', companyRoute);
//Redirect any server request back to index.html: To deal with CRS
app.get('/', function(req, res, next){
res.sendFile(path.join(__dirname, '../client', 'index.html'));
})
//Hostname and Port
//const hostname = '127.0.0.1';
const port = 3000;
app.listen(port, () => {
console.log(`Backend server is running at http://localhost:${port}/`);
});
An error that is showing up in the console/network and postman. It looks like the http.get request is being stalled

Seems you forgot a / in your route http:/localhost:3000/api/companies/.... Change it to http://... and that should fix your issue.