NodeJS error: internal/modules/cjs/loader.js:905-Cannot find module './config'

Question

I'm getting the following console error in my node application: Error: Cannot find module './config'

I've read up on similar questions (e.g. internal/modules/cjs/loader.js:582 throw err) so I've checked for duplicative folder/file names but could I be missing something?

Below is the full error I'm getting in the console after the "node app.js" command.

internal/modules/cjs/loader.js:905
  throw err;  
  ^

Error: Cannot find module './config'
Require stack:
- C:\Users\arthu\development\projectWhereWoof\dustyv3\backend\config\db.js
- C:\Users\arthu\development\projectWhereWoof\dustyv3\backend\app.js
  at Function.Module._resolveFilename (internal/modules/cjs/loader.js:902:15)
  at Function.Module._load (internal/modules/cjs/loader.js:746:27)
  at Module.require (internal/modules/cjs/loader.js:974:19)
  at require (internal/modules/cjs/helpers.js:92:18)
  at Object.<anonymous (C:\Users\arthu\development\projectWhereWoof\dustyv3\backend\config\db.js:2:16)
  at Module._compile (internal/modules/cjs/loader.js:1085:14)
  at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
  at Module.load (internal/modules/cjs/loader.js:950:32)
  at Function.Module._load (internal/modules/cjs/loader.js:790:14)
  at Module.require (internal/modules/cjs/loader.js:974:19)
  at require (internal/modules/cjs/helpers.js:92:18)
  at Object.<anonymous> (C:\Users\arthu\development\projectWhereWoof\dustyv3\backend\app.js:2:19)
  at Module._compile (internal/modules/cjs/loader.js:1085:14)
  at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
  at Module.load (internal/modules/cjs/loader.js:950:32)
  at Function.Module._load (internal/modules/cjs/loader.js:790:14) {
code: 'MODULE_NOT_FOUND',
requireStack: [
'C:\\Users\\arthu\\development\\projectWhereWoof\\dustyv3\\backend\\config\\db.js',
'C:\\Users\\arthu\\development\\projectWhereWoof\\dustyv3\\backend\\app.js'
  ]
}

Below is my folder structure and code that I'm running.

• backend
  • config
    • db.js
    • default.json
  • models
    • Dogs.js
  • node_modules
  • routes
    • dogs.js
  • app.js
  • package-lock.json
  • package.json

---

//app.js
const express = require('express');
const connectDB = require('./config/db');
var cors = require('cors');
// routes
const dogs = require('./routes/dogs');
const app = express();
// Connect Database
connectDB();
// cors handling logic
app.use(cors({ origin: true, credentials: true }));
// Init Middleware
app.use(express.json({ extended: false }));
app.get('/', (req, res) => res.send('Hello world!'));
// use Routes
app.use('./routes/dogs', dogs);
const port = process.env.PORT || 8082;
app.listen(port, () => console.log(`Server running on port ${port}`));

---

//db.js
const mongoose = require('mongoose');
const config = require('./config');
const db = config.get('mongoURI');

const connectDB = async () => {
   try {
     await mongoose.connect(
       db,
       {
         useNewUrlParser: true,
         useUnifiedTopology: true 
       }
    );

    console.log('MongoDB is Connected...');
  } catch (err) {
    console.error(err.message);
    process.exit(1);
  }
};
module.exports = connectDB;

---

//default.json
{
"mongoURI":
  "mongodb+srv://INTENTOMITTED:INTENTOMITTED@INTENTOMITTED.oxagu.mongodb.net/myFirstDatabase?retryWrites=true&w=majority"
}

---

//Dogs.js
const mongoose = require('mongoose');
const DogSchema = new mongoose.Schema({
  name: {
    type: String,
    required: true
  },
  breedTypePrim: {
    type: String,
    required: true
  },
  breedTypeSec: {
    type: String,
    required: false
  },
  birthday: {
    type: Date,
    required: false
  },
  adoptionDate: {
    type: Date,
    required: true
    },
  weight: {
      type: Number,
      required: false
    },
  origin: {
    type: String,
    required: false
  }
});

module.exports = Dog = mongoose.model('dog', DogSchema);

---

//dogs.js
const express = require('express');
const router = express.Router();

// Load Dog model
const Dog = require('../models/Dogs');

// @route GET api/dogs/test
// @description tests dogs route
// @access Public
router.get('/test', (req, res) => res.send('dog route testing!'));

// @route GET api/dogs
// @description Get all dogs
// @access Public
router.get('/', (req, res) => {
  Dog.find()
    .then(dogs => res.json(dogs))
    .catch(err => res.status(404).json({ nodogsfound: 'No Dogs found' }));
});

// @route GET api/dogs/:id
// @description Get single dog by id
// @access Public
router.get('/:id', (req, res) => {
  Dog.findById(req.params.id)
    .then(dog => res.json(dog))
    .catch(err => res.status(404).json({ nodogfound: 'No Dog found' }));
});

// @route GET api/dogs
// @description add/save dog
// @access Public
router.post('/', (req, res) => {
  Dog.create(req.body)
    .then(dog => res.json({ msg: 'Dog added successfully' }))
    .catch(err => res.status(400).json({ error: 'Unable to add this dog' }));
});

// @route GET api/dogs/:id
// @description Update dog
// @access Public
router.put('/:id', (req, res) => {
  Dog.findByIdAndUpdate(req.params.id, req.body)
    .then(dog => res.json({ msg: 'Updated successfully' }))
    .catch(err =>
      res.status(400).json({ error: 'Unable to update the Database' })
    );
});

// @route GET api/dogs/:id
// @description Delete dog by id
// @access Public
router.delete('/:id', (req, res) => {
  Dog.findByIdAndRemove(req.params.id, req.body)
    .then(dog => res.json({ mgs: 'Dog entry deleted successfully' }))
    .catch(err => res.status(404).json({ error: 'No such a dog' }));
});

module.exports = router;

Answer 1

In db.js file you have const config = require('./config');, the system will search for config.js file in the same folder of db.js file, which isn't available, hence the error.

To read the default.json file and get the mongodb connection string, you can try this way:

const config = require('./default.json'); // config is a javascript object
const db = config.mongoURI;