CRUD API - 500 Internal Server Error with Postman

Question

Problem

I'm creating a Node.js Rest APIs with Express, Sequelize, Sequelize-cli and MySQL, but when I tested it with a Post request, the one creating a new user, on Postman I always got a 500 Internal Server Error.

Trials

I tried with a GET request, to see if I could get the data about a previously created user, but I again get a 500 Internal Server Error.

I already checked my database, but everything is ok there. There is both my database and the tables as you can see here.

And I also checked that the connection with the database was established trough:

sequelize.authenticate().then(()=>{
console.log('Connection has been established successfully!');
}).catch (error =>{
console.error('Unable to connect to the database!');
});

I also checked my routes, controllers, and package to see if I forgot a dependency or something, but I found no problem :/.

Code

Here is my code:

At the root of the project:

server.js

const express = require("express");
const cors = require("cors");
const userRoutes = require("./routes/user.routes.js");

const app = express();

var corsOptions = {
    origin: "http://localhost:8081"
};

app.use(cors(corsOptions));

app.use(express.json());

app.use(express.urlencoded({ extended: true }));

app.use((req, res, next) => {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content, Accept, Content-Type, Authorization');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, PATCH, OPTIONS');
    next();
});

app.use('/api/users', userRoutes);

const PORT = 8080;
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}.`);
});

From there, I used Sequelize-CLI to create a user model in models folders:

user.js

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('users', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      firstName: {
        type: Sequelize.STRING
      },
      lastName: {
        type: Sequelize.STRING
      },
      email: {
        type: Sequelize.STRING
      },
      password: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('users');
  }
};

Then, I created his controllers and its routes, respectively in the controllers and routes folders:

user.controller.js

const  user = require("../models/user.js");
const Sequelize = require("../models/index.js");

const Op = Sequelize.Op;

let self = {};

self.createUser = async (req, res) => {
    if (!req.body.firstName || !req.body.lastName) {
        res.status(400).send({
            success: false,
            message: "Content can not be empty!"
        });
        return;
    }
    try {
        const newUser = {
            firstName: req.body.firstName,
            lastName: req.body.lastName,
            email: req.body.email,
            password: req.body.password
        };
        let data = await user.create(newUser);
        return res.status(201).json({
            success: true,
            data: data
        })
    } catch (error) {
        return res.status(500).json({
            success: false,
            error: error
        })
    }
}

self.get = async (req, res) => {
    try {
        let id = req.params.id;
        let data = await user.findByPk(id,
            {
                where: {
                    id: id
                },
                include: [{
                    model: project,
                    as: 'projects'
                }]
            }
        );
        if (data)
            return res.status(200).json({
                success: true,
                data: data
            })
        else
            return res.status(200).json({
                success: false,
                error: "No such user present",
                data: []
            })
    } catch (error) {
        res.status(500).json({
            success: false,
            error: error
        })
    }
}

module.exports = self;

user.routes.js

const user = require("../controllers/user.controller.js");
const router = require("express").Router();

router.get('/', user.getAll);
router.get('/:id', user.get);
router.post('/', user.createUser);
router.put('/:id', user.updateUser);
router.delete('/:id', user.delete);
router.delete('/', user.deleteAll);

module.exports = router;

By the way, there is also the config.json in the config folder:

{
  "development": {
    "username": "root",
    "password": "MhSyLoPoLoMY8Hg&",
    "database": "groupomania",
    "host": "localhost",
    "dialect": "mysql"
  },
  "test": {
    "username": "root",
    "password": null,
    "database": "database_test",
    "host": "127.0.0.1",
    "dialect": "mysql"
  },
  "production": {
    "username": "root",
    "password": null,
    "database": "database_production",
    "host": "127.0.0.1",
    "dialect": "mysql"
  }
}

Here's the log statement of the 500 internal error:

POST http://localhost:8080/api/users
500
8 ms
POST /api/users HTTP/1.1
Content-Type: application/json
User-Agent: PostmanRuntime/7.32.3
Accept: */*
Postman-Token: 6d67840d-fa40-46ca-9849-ec2847236d19
Host: localhost:8080
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Length: 131
 
{
"firstName": "testfirstName",
"lastName": "testlastName",
"email": "testemail",
"password": "passwordpassword"
}
 
HTTP/1.1 500 Internal Server Error
X-Powered-By: Express
Access-Control-Allow-Origin: *
Vary: Origin
Access-Control-Allow-Headers: Origin, X-Requested-With, Content, Accept, Content-Type, Authorization
Access-Control-Allow-Methods: GET, POST, PUT, DELETE, PATCH, OPTIONS
Content-Type: application/json; charset=utf-8
Content-Length: 28
ETag: W/"1c-9j3+7zIZYFzBJCw8ZKi1q8+V98A"
Date: Sun, 25 Jun 2023 16:09:47 GMT
Connection: keep-alive
Keep-Alive: timeout=5
 
{"success":false,"error":{}}

Thank you in advance for any help someone can offer me.

P.S: Here is my project repository, if you need to see more :D. Or just ask me, I will do my best to answer you :).

Answer 1

In user.controller.js:

const { user, Sequelize, project } = require("../models");

user and project are all undefined here. Check the models/index.js, export user and project correctly.

p.s. I suggest you to learn how to debug nodejs using nodemon, so you can figure out the reason of most problems by yourself: How to debug application using nodemon in nodeJs