Develop Reference

Data not Found as POST request returns `JSON.stringify(value); TypeError: Converting circular structure to JSON`

I have two functions in functions.js - postData and startProcess. I am calling both functions in a function in server.js called sendData. sendData is then called in the app.post route.
In sendData, getData is called first and returns an id. This id is passed to startProcess and after it is run, a message that says 'success` should be printed. If it fails, a message that says 'failed to complete process should be returned'.
It seems like postData runs successfully, but startProcess is unable to pick or use its response as id.
When I run just the postData function in SendData, I get this error message:
JSON.stringify(value);
TypeError: Converting circular structure to JSON
What am I missing and how can I properly implement this?
functions.js
const axios = require("axios");
const BASE_URL = "http://localhost:1770";
const startProcess = async (id) => {
const headers = {
"Content-type": "application/json",
};
try {
return axios.post(`${BASE_URL}/start/${id}`, { headers });
} catch (error) {
console.error(error);
}
};
const postData = async (body) => {
const headers = {
"Content-type": "application/json",
};
try {
return axios.post(`${BASE_URL}/data`, body, { headers });
} catch (error) {
console.error(error);
}
};
server.js
const express = require("express");
const process = require("./functions.js");
const payload = require("./payload.json");
const res = require("express/lib/response");
// Create Express Server
const app = express();
app.use(cors());
// Configuration-api
const PORT = 5203;
app.use(express.json());
const sendData = async (req, res, next) => {
const body = payload;
try {
const response = await process.postData(body);
if ((response.status = 200)) {
let id = response.data;
const processResult = await process.startProcess(id);
if ((processResult.status = 200)) {
res.send("successfully started process");
}
}
} catch (error) {
console.error(error);
}
};
app.post("/data", sendData);
app.listen(PORT, () => {
console.log(`Running this application on the PORT ${PORT}`);
});

"Cannot set headers after they are sent to the client" for private routes after logging in JWT NodeJS

I am working on a backend for a Online mediconsult app and I came across this error in the JWT authentication. Since I am a newbie I dunno much about this topic. I have this 3 routes on my NodeJS /register, /login, /appointments. I was able to hit "/register" and "/login" perfectly fine. But when I copy the JWT token generated by "/login" route and paste it 'authorization' header it throws the problem.
node:internal/errors:484
ErrorCaptureStackTrace(err);
^
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at new NodeError (node:internal/errors:393:5)
at ServerResponse.setHeader (node:_http_outgoing:644:11)
at ServerResponse.header (C:\Users\krish\Desktop\mrcooper-task\server\node_modules\express\lib\response.js:794:10)
at ServerResponse.send (C:\Users\krish\Desktop\mrcooper-task\server\node_modules\express\lib\response.js:174:12)
at module.exports.login (C:\Users\krish\Desktop\mrcooper-task\server\controllers\authController.js:62:7) {
code: 'ERR_HTTP_HEADERS_SENT'
}
Node.js v18.12.0
A strange thing is, when I restart the server again with the same auth token, it works!.
Wonder why would it hit the above error before restarting ?
Code
index.js
const express = require("express");
const cors = require("cors");
const mongoose = require("mongoose");
const app = express();
require('dotenv').config();
//External routes
const authRoutes = require("./routes/authRoutes");
const appointRoutes = require("./routes/appointRoutes");
// Middlewares
app.use(cors());
app.use(express.json());
//DB connection
const dbURI =
process.env.DB_URL;
mongoose
.connect(dbURI, { useNewUrlParser: true, useUnifiedTopology: true })
.then((result) =>
app.listen(8080, () =>
console.log("App sucessfully started on localhost port 8080")
)
)
.catch((err) => console.log(err));
//Internal routes
app.use(authRoutes);
app.use(appointRoutes);
appointRoutes.js
const { Router } = require("express");
const verify = require("./verifyToken")
const router = Router();
router.get("/appointments",verify, (req, res) => {
res.send({ message: "Appointment route" });
});
module.exports = router;
authRoutes.js
const { Router } = require("express");
const User = require("../models/User");
const bcrypt = require("bcryptjs");
const jwt = require("jsonwebtoken");
const { registerValidator, loginValidator } = require("../validation");
const router = Router();
router.post("/register", async (req, res) => {
//Validate data before creating a user
const { error } = registerValidator(req.body);
if (error) {
return res.status(400).send(error.details[0].message);
}
//Check if email already exists
const emailExists = await User.findOne({ email: req.body.email });
if (emailExists) {
return res.status(400).send("Email already exists");
}
const { name, email, password, catogery, DOB } = req.body;
//Hash password
const salt = await bcrypt.genSalt(10);
const hashedPassword = await bcrypt.hash(password, salt);
//console.log(hashedPassword);
try {
const user = await User.create({
name,
email,
password: hashedPassword,
catogery,
DOB,
});
res.status(201).json({ user: user._id });
} catch (err) {
//console.log(err);
res.status(400).send(err);
}
});
router.post("/login", async (req, res) => {
const { email, password } = req.body;
//Validate data before authenticating a user
const { error } = loginValidator(req.body);
if (error) {
return res.status(400).send(error.details[0].message);
}
//Check if email dosen't exists
const user = await User.findOne({ email: req.body.email });
if (!user) {
return res
.status(400)
.send("Email dosen't exists. Please register and try again");
}
//Passowrd is incorrect
const validPassword = await bcrypt.compare(password, user.password);
if (!validPassword) return res.status(400).send("Invalid Passowrd");
//Create and assign JWT token
const token = jwt.sign({_id: user._id}, process.env.TOKEN_SECRET)
res.header('auth-token', token).send(token);
//console.log(email, password);
res.send("Logged In!");
});
module.exports = router;
Here's what I did
I did few googles and searches on this error and found out that this error mainly throws out when we return multiple response per cycle. I checked the code below and I did'nt see multiple response coming from neither /login route nor /appointments route. Would there be any response leaks from if conditions accidentaly?
When I exit from nodemon and start again with the same take generated, now it can hit the /appointment. I wonder how it works ?

You get error when function like this
if(statement){
res.send(something)
}
res.send(something)
because code is continue after res.send() function
You must fix it to
if(statement){
return res.send(something)
}
return res.send(something)
and your res.send function in authController.js:62:7

There is some issue when I try to get data from mongodb by node.js?

This is my index.js. When I hit my API using postman, there is a bug in my getdata() method code that causes it to return the else statement rather than finding the requested resource. I'm not sure why the data targeting by ID can't be found. When I use console.log to test my code, the try statement is entered but did not find anything from the database and catch statement is returned.
const connectToMongo = require('./db');
var cors = require('cors');
const express = require('express');
const bodyParser = require('body-parser');
const photo = require('./models/photoModel');
const formidable = require('formidable');
const fs = require('fs');
const photoModel = require('./models/photoModel');
connectToMongo();
const app = express();
app.use(cors());
const port = 5000;
//app.use(express.json());
app.use(bodyParser.json());
const userData = (req, res) => {
const form = new formidable.IncomingForm();
console.log('1');
form.parse(req, (err, fields, file) => {
console.log('2');
if (fields) {
console.log('3');
const { email, mno, name } = fields;
if (!email || !mno || !name) {
console.log('4');
return res.status(400).json({
error: 'Fill all the fields',
});
}
}
if (file.photo) {
if (file.photo.size > 4000000) {
return res.status(400).json({
error: 'image size is too long',
});
}
const user = new photo(fields);
user.photo.data = fs.readFileSync(file.photo.filepath);
user.photo.contentType = file.photo.type;
user.save((err, user) => {
if (err) {
return res.status(400).json({
error: 'Not save in db',
});
}
console.log('above json');
res.json(user);
});
}
});
};
// The issue is here
const getdata = async (req, res) => {
try {
console.log('yes');
const photo = await photo.find({ photo: req.photo.id });
res.json(photo);
} catch (error) {
return res.status(400).json({
error: 'not find',
});
}
};
//router
app.post('/userdashboard', userData);
app.get('/getdata', getdata);
app.listen(port, () => {
console.log(`Dashboard Backend listening on port ${port}`);
});
This is my modelschema
const mongoose = require('mongoose');
const { Schema } = mongoose;
const PhotoSchema = new Schema({
name:{
type:String,
trim:true,
required:true
},
email:{
type:String,
trim:true,
required:true
},
photo:{
data:Buffer,
contentType:String
},
mno:{
type:Number,
required:true
}
});
module.exports=mongoose.model('photo',PhotoSchema);

First mistake you did was not adding console.error(error), if you did it would have shown exact error message.
In this case req.photo is undefined and you are trying to access id property of undefined which causes error to be thrown.
const getdata = async (req, res) => {
try {
const { photo } = req.body
// TODO: use custom error class for validation errors instead of default Error class
if (!photo) throw new Error('photo is missing')
if (!photo.id) throw new Error('photo.id is missing')
// TODO: validate photo.id is valid monogoid
const photos = await photo.find({ photo: photo.id })
res.json(photos)
} catch (error) {
console.error(error) // <-- this was missing
res.status(400).json({ error: 'not find' }) // provide good error message
return
}
}

CRUD operations using mongoose and express

I am creating an express app using mongoose with the intention of connecting this to React for the frontend.
I have listed some CRUD operations for a customer controller below but there are a few things I do not like about this approach.
When using Customer.findById with a valid ObjectID that is not found, it returns null with a 200 response code. I want this to return 404 if no customer was found. I realise I could change the catch response to a 404, but I want to have some generic error handling incase the server goes down during the request or an invalid ObjectId was provided, which brings me to my next item.
If I provide an invalid ObjectId I want to provide some meaningful message, is 500 the right response code?
Error handling: Am I returning errors the correct way? currently errors return a string with the error message. Should I return JSON instead? e.g. res.status(500).json({error: error.message). I am planning on connecting this to react (which I am still learning) and I assume the UI will need to display these messages to the user?
findById is repeated in getCustomerById, updateCustomer, and deleteCustomer. I feel this is bad practice and there must be a more streamlined approach?
I want to have one function that validates if the ObjectId is valid. I am aware that I can do this is the routes using router.params but I'm not sure if checking for a valid id should be in the routes file as it seems like something the controller should be handling? See routes example below from another project I did.
What are the best practices and suggested ways to improve my code, based on the above?
I have read the documentation from mongoose, mozilla, and stackoverflow Q&A but they don't seem to address these issues (at least I could not find it).
I am really after some guidance or validation that what I am doing is correct or wrong.
customer.controller.js
const Customer = require("../models/customer.model");
exports.getCustomers = async (req, res) => {
try {
const customers = await Customer.find();
res.status(200).json(customers);
} catch (error) {
res.status(500).send(error.message);
}
};
exports.getCustomerById = async (req, res) => {
try {
const customer = await Customer.findById(req.params.id);
res.status(200).json(customer);
} catch (error) {
res.status(500).send(error.message);
}
};
exports.addCustomer = async (req, res) => {
try {
const customer = new Customer(req.body);
await customer.save().then(res.status(201).json(customer));
} catch (error) {
res.status(500).send(error.message);
}
};
exports.updateCustomer = async (req, res) => {
try {
const customer = await Customer.findById(req.params.id);
Object.assign(customer, req.body);
customer.save();
res.status(200).json(customer);
} catch (error) {
res.status(500).send(error.message);
}
};
exports.deleteCustomer = async (req, res) => {
try {
const customer = await Customer.findById(req.params.id);
await customer.remove();
res.status(200).json(customer);
} catch (error) {
res.status(500).send(error.message);
}
};
Router.params example
This is a routes file (not related to my current app) and is provided as an example of how I have used router.params in the past.
const express = require("express");
const router = express.Router();
const mongoose = require("mongoose");
const Artist = require("../models/Artist");
const loginRequired = require("../middleware/loginRequired");
const {
getArtists,
addArtist,
getArtistById,
updateArtist,
deleteArtist,
} = require("../controllers/artistController");
router
.route("/")
.get(loginRequired, getArtists) // Get all artists
.post(loginRequired, addArtist); // Create a new artist
router
.route("/:id")
.get(loginRequired, getArtistById) // Get an artist by their id
.put(loginRequired, updateArtist) // Update an artist by their id
.delete(loginRequired, deleteArtist); // Delete an artist by their id
router.param("id", async (req, res, next, id) => {
// Check if the id is a valid Object Id
if (mongoose.isValidObjectId(id)) {
// Check to see if artist with valid id exists
const artist = await Artist.findOne({ _id: id });
if (!artist) res.status(400).json({ errors: "Artist not found" });
res.locals.artist = artist;
res.locals.artistId = id;
next();
} else {
res.status(400).json({ errors: "not a valid object Id" });
}
});
module.exports = router;

i personly like to make error handeling more global so i would write something like
constPrettyError = require('pretty-error')
const pe = new PrettyError()
const errorHandler = (err, req, res, next) => {
if (process.env.NODE_ENV !== 'test') {
console.log(pe.render(err))
}
return res
.status(err.status || 500)
.json({ error: { message: err.message || 'oops something went wrong' } })
}
module.exports = errorHandler
as a handler
the in your index / server file
app.use(errorHandler)
then in your handlers just
} catch (err) {
next(err);
}
as an example
if (!artist) next({ message: "Artist not found" ,status:404 });
also, note that you can customize this error handler to switch case (or object) a custom error per status as well if you want
const errorHandler = (err, req, res, next) => {
if (process.env.NODE_ENV !== 'test') {
console.log(pe.render(err))
}
const messagePerStatus = {
404: 'not found',
401: 'no authorization'
}
const message = messagePerStatus[err.status]
return res
.status(err.status || 500)
.json({
error: { message: message || err.message || 'oops something went wrong' }
})
}
then just
if (!artist) next({status:404 });

I also agree with answer by Asaf Strilitz but still need to show what i do in my projects
Create a custom error class
AppError.js
class AppError extends Error {
constructor(statusCode, message) {
super();
// super(message);
this.statusCode = statusCode || 500 ;
this.message = message || "Error Something went wrong";
}
}
module.exports = AppError;
Create an error handling middleware
errors.js
const AppError = require("../helpers/appError");
const errors = (err, req, res, next) => {
// console.log(err);
let error = { ...err };
error.statusCode = error.statusCode;
error.message = error.message;
res.status(error.statusCode).json({
statusCode: err.statusCode,
message: err.message,
});
};
exports.errors = errors;
Create a middleware to validate object id
validateObjectId.js
const mongoose = require("mongoose");
const AppError = require("appError");
module.exports = function (req, res, next) {
const { _id } = req.params;
if (_id && !mongoose.Types.ObjectId.isValid(_id)) {
throw new AppError(422, "Invalid ID field in params");
}
next();
};
In your app.js
const { errors } = require("errors");
// At the end of all middlewares
// Error Handler Middleware
app.use(errors);
In your routes file
const express = require("express");
const router = express.Router();
const mongoose = require("mongoose");
const Artist = require("../models/Artist");
const loginRequired = require("../middleware/loginRequired");
const validateId = require("validateObjectId");
const {
getArtists,
addArtist,
getArtistById,
updateArtist,
deleteArtist,
} = require("../controllers/artistController");
// Your routes
router
.route("/:id")
.get(validateId, loginRequired, getArtistById) // Get an artist by their id
.put(validateId, loginRequired, updateArtist) // Update an artist by their id
.delete(validateId, loginRequired, deleteArtist); // Delete an artist by their id
module.exports = router;
Now regarding findById method being repeated i dont see anything bad in that as it is specific to database call still you can introduce a staic method on model itself or create a single method on cntroller but still need to check if it returns the found object or not and handle the error on that.

403 forbidden error when using fetch in node.js

I am trying to get a response from '/razorpay' route in my index.js file, and use it in displayRazorpay()
. For this, I'm using fetch, but it shows forbidden 403 error. Can someone help out? I have attached my '/razorpay' route, and displayRazorpay() function below. I'm new to node.js, so any help is appreciated!
router.post('/razorpay', async function(req,res,next){
if(!req.session.cart){
return res.redirect('/shopping-cart');
}
var cart = new Cart(req.session.cart);
const payment_capture = 1;
const amount = cart.totalPrice;
const currency = 'INR';
const options = {
amount: amount * 100,
currency,
receipt: shortid.generate(),
payment_capture,
}
try {
const response = await razorpay.orders.create(options);
console.log(response);
res.json({
id: response.id,
currency: response.currency,
amount: response.amount
});
} catch (error) {
console.log(error);
}
});
async function displayRazorpay() {
const data = await fetch('/razorpay', {method:'POST'}).then((t) =>
t.json()
);
console.log(data);
const options = {
key: 'rzp_test_2eJE3rP3gEWqze',
amount: 400,
order_id: data.id,
name: 'Donation',
description: 'Thank you for nothing. Please give us some money',
image: '/images/modiLogo3.png',
handler: function (response) {
alert(response.razorpay_payment_id);
alert(response.razorpay_order_id);
alert(response.razorpay_signature);
},
prefill: {
email: 'sdfdsjfh2#ndsfdf.com',
phone_number: '9899999999'
}
}
const paymentObject = new window.Razorpay(options);
paymentObject.open();
}

This is a problem of CORS. Make sure you enable cors on your server side.
Since you are using express, here's sample code
First install cors: npm install cors
var express = require('express')
var cors = require('cors')
var app = express()
app.use(cors())
app.get('/products/:id', function (req, res, next) {
res.json({msg: 'This is CORS-enabled for all origins!'})
})
app.listen(80, function () {
console.log('CORS-enabled web server listening on port 80')
})