Не удается прочитать свойства undefined (чтение «findOne») с приложением React, развернутым на Heroku

У меня возникли проблемы после того, как я развернул свое приложение (бэкенд на Heroku и интерфейс на Netlify). Раньше на локалхосте работало нормально

Проблема

Пока я делал запрос API (логин или SIgnUP) из внешнего интерфейса, он показывает мне ошибку.

Cannot read properties of undefined (reading 'findOne')

В журнале Heroku сказано, что это Connected to Mongo Successfully, но я все равно получаю эту ошибку.

Что я думаю

Я создал удаленное облако MongoDB на MOngoAtlas следующим образом:

И я подключил его к своему db.js вот так

const mongoose = require("mongoose");
//const mongoURI = "mongodb://localhost:27017/?readPreference=primary&appname=MongoDB%20Compass&ssl=false";
const mongoURI = "mongodb+srv://mohit_maroliya:Zker42FNU.buD_E@cluster0.n03hm.mongodb.net/myFirstDatabase?retryWrites=true&w=majority"

const connectToMongo = async() => {
    mongoose.connect(mongoURI, {useNewUrlParser: true}, ()=> {
        console.log("Connected to Mongo Successfully!");
    })
}

module.exports = connectToMongo;

Поэтому я думаю, что мое соединение с Mongo подключено, но не к этой базе данных.

Также в консоли Google отображается Unexpected token i in JSON at position 0

Код

Я делюсь кодом задействованных файлов

< Сильный > auth.js

const express = require("express");
const { body, validationResult } = require("express-validator");
const router = express.Router();
const { User } = require("../models/User");
const bcrypt = require("bcryptjs");
const jwt = require("jsonwebtoken");
const JWT_SECRET = "mohitisagood$boy";
const fecthUser = require("../middleware/fetchUser");

//ROUTE 1 :Creating a User :POST - "/api/auth/createuser"
router.post(
  "/createuser",
  [
    body("name", "Name must have at least 3 characters").isLength({ min: 3 }),
    body("email", "Enter a valid email").isEmail(),
  ],
  async (req, res) => {

    let success = false;
    //If there are errors, then return bad request + Errors
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({success, errors: errors.array() });
    }

    try {
      //Check whether email exists
      //let user;
      let user = await User.findOne({ email: req.body.email });
      console.log("user.nemail = " + user);
      if (user) {
        //console.log(user.email);
        return res.status(400).json({success, error: "Email Already Taken" });
      }

      //hashing the password here
      const salt = await bcrypt.genSalt(10);
      const secPass = await bcrypt.hash(req.body.password, salt);
      //user is created
      user = await User.create({
        name: req.body.name,
        email: req.body.email,
        password: secPass,
      });

      //passing the id as data to make jwt token
      const data = {
        user: {
          id: user.id,
        },
      };

      const authToken = jwt.sign(data, JWT_SECRET);
      //console.log(authToken)

      
      success = true;
      //res.json(user);
      res.json({success, authToken });
    } catch (error) {
      console.log(error.message);
      res.status(500).send("internal server error");
    }
  }
);

//ROUTE 2 :Authenticating a User :POST - "/api/auth/login"
router.post(
  "/login",

  body("email", "Enter a valid email").isEmail(),

  async (req, res) => {
    //If there are errors, then return bad request + Errors
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }

    const { email, password } = req.body;
    
    let success = false;

    try {
      let user = await User.findOne({ email });

      // console.log("user - "+user)

      if (!user) {
        res.status(400).json({success,error:"Login with correct credentials!"});
      }

      //compare the pwd bw 'hash of pwd entered' & 'hash from your pwdDB'
      const passwordCompare = await bcrypt.compare(password, user.password);

      if (!passwordCompare) {
        res.status(400).json({success,error:"Login with correct credentials!"});
      }
      //nodemon crashes whenever PASSWORD === NULL


      const payload = {
        user: {
          id: user.id,
        },
      };

      const authToken = jwt.sign(payload, JWT_SECRET);
      
      success = true;
      res.json({ success, authToken });
    } catch (error) {
      console.log(error.message);
      res.status(500).send("Internal Server Error");
    }
  }
);



module.exports = router;

Модель (User.js)

const mongoose = require("mongoose");
const { Schema } = mongoose;

const UserSchema = new Schema({
  name: {
    type: String,
    required: true,
  },
  email: {
    type: String,
    required: true,
  },
  password: {
    type: String,
    required: true,
    validate(value) {
      if(value.length < 5) {
        throw new Error( "Minimum length is 5 characters");
      }
      else if (!value.match(/\d/) || !value.match(/[a-zA-Z]/) ) {
        throw new Error(
          "Password must contain at least one letter and one number"
        );
      }

    }
    
  },
  date: {
    type: Date,
    default: Date.now,
  },
});

const User = mongoose.model("users", UserSchema);
module.exports = User;

Login.js (интерфейс)

import React, { useState } from "react";
import { useHistory } from "react-router-dom";
import imgpath from "../assets/notepic.jpg";
import { motion } from "framer-motion";

const Login = (props) => {
  let history = useHistory();
  
  const [credentials, setCredentials] = useState({ email: "", password: "" });

  const onChange = (e) => {
    setCredentials({ ...credentials, [e.target.name]: e.target.value });
    //input mei value typed ho sake,jaise jaise value change ho vese-vese note me set ho jaye
  };

  const goToSignup = () => {
    history.push("/signup");
  };
  
  const handleSubmit = async (e) => {
    e.preventDefault();
    const response = await fetch(`https://my-notebook-mohit.herokuapp.com:/api/auth/login`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        email: credentials.email,
        password: credentials.password,
      }),
    });
    const json = await response.json();
    if (json.success === true) {
      //storing the authtoken
      localStorage.setItem("token", json.authToken);
      props.showAlert("User logged in successfully", "info");
      history.push("/");
    } else {
      props.showAlert("invalid Credentials", "danger");
    }
    console.log(json);
  };

  return (
    <motion.div className="container" id="manku" animate={{scale:[0.5,1]}} transition={{times:[0.1,0.4], ease:'easeInOut'}}>
      <div id="picturebody">
        <img src={imgpath} alt="note-pic" width="100%" />
      </div>
      <div id="loginbody">
        <div className="mt-3">
          <h2 className="my-3"> Login to continue</h2>
          <form onSubmit={handleSubmit} className="login-form">
            .
            .
            .
          </form>
          <div className="text-center my-5" id="bottom-text">
            mynotebook
        </div>
        </div>
      </div>
    </motion.div>
  );
};

export default Login;

Heroku Logs

2022-01-26T12:04:28.024784+00:00 heroku[web.1]: Starting process with command `npm start`
2022-01-26T12:04:29.075584+00:00 app[web.1]: 
2022-01-26T12:04:29.075596+00:00 app[web.1]: > my-notebook-backend@1.0.0 start
2022-01-26T12:04:29.075596+00:00 app[web.1]: > node index.js
2022-01-26T12:04:29.075596+00:00 app[web.1]: 
2022-01-26T12:04:29.561386+00:00 app[web.1]: my-notebook backend listening at https://my-notebook-mohit.herokuapp.com:38751
2022-01-26T12:04:29.561856+00:00 app[web.1]: Connected to Mongo Successfully!
2022-01-26T12:04:29.766495+00:00 heroku[web.1]: State changed from starting to up
2022-01-26T12:04:05.000000+00:00 app[api]: Build started by user maroliya.1@iitj.ac.in
2022-01-26T12:04:24.985213+00:00 app[api]: Release v32 created by user maroliya.1@iitj.ac.in
2022-01-26T12:04:24.985213+00:00 app[api]: Deploy c9d42533 by user maroliya.1@iitj.ac.in
2022-01-26T12:04:25.000000+00:00 app[api]: Build succeeded
2022-01-26T12:06:05.906508+00:00 heroku[router]: at=info method=OPTIONS path="/api/auth/login" host=my-notebook-mohit.herokuapp.com request_id=a4c47a5b-a85b-469e-a595-f1ed356e2373 fwd="27.56.201.36" dyno=web.1 connect=0ms service=5ms status=204 bytes=301 protocol=https
2022-01-26T12:06:06.155157+00:00 app[web.1]: Cannot read properties of undefined (reading 'findOne')
2022-01-26T12:06:06.163135+00:00 heroku[router]: at=info method=POST path="/api/auth/login" host=my-notebook-mohit.herokuapp.com request_id=02849e70-a653-4751-a6dc-de73cf7a2bf2 fwd="27.56.201.36" dyno=web.1 connect=0ms service=34ms status=500 bytes=272 protocol=https
2022-01-26T12:06:21.493881+00:00 heroku[router]: at=info method=POST path="/api/auth/createuser" host=my-notebook-mohit.herokuapp.com request_id=27e52b6b-6931-4797-9296-2a81cf1c8399 fwd="27.56.201.36" dyno=web.1 connect=0ms service=4ms status=500 bytes=272 protocol=https
2022-01-26T12:06:21.291315+00:00 heroku[router]: at=info method=OPTIONS path="/api/auth/createuser" host=my-notebook-mohit.herokuapp.com request_id=25d391ad-d14c-4999-b9da-18c1328ce0cd fwd="27.56.201.36" dyno=web.1 connect=0ms service=1ms status=204 bytes=301 protocol=https
2022-01-26T12:06:21.491373+00:00 app[web.1]: Cannot read properties of undefined (reading 'findOne')

Пожалуйста, помогите мне, потому что я борюсь с этим в течение длительного времени.