Search code examples
javascriptnode.jstypescripttypeorm

MODULE_NOT_FOUND issue in node.js

I stuck at MODULE_NOT_FOUND , I have checked other questions related to it and tried their soultions but could not get succeed. Any help will be appreciated. Thanks.

I am trying to create node.js with mysql db using TypeORM and trying to import User entity created in entity folder where I have file name User.ts

enter image description here

This is my folder structure.

Below is package.json

{
  "name": "mysql-typeorm",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "nodemon app.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@types/express": "^4.17.17",
    "@types/node": "^18.14.6",
    "express": "^4.18.2",
    "mysql2": "^3.2.0",
    "nodemon": "^2.0.21",
    "reflect-metadata": "^0.1.13",
    "ts-node": "^10.9.1",
    "typeorm": "^0.3.12",
    "typescript": "^4.9.5"
  }
}

Below is my app.js

const express = require('express')
const { User } = require('./entity/User')

const { DataSource , createConnection} =  require('typeorm')
const app = express()

const port = 3000 || process.env.port

app.listen(port , () => {
    console.log(`server is listening on ${port}`)
})

const appDataSource = new DataSource({
    type:"mysql",
    host:"localhost",
    port:3308,
    username:"root",
    password:"",
    database:"booksDB",
    synchronize:true,
    logging:true,
    entities:[User]
});

appDataSource.initialize().then((res)=> {
    console.log(`db is connected`)
}).catch((err) => {
    console.log(`${err}`)
})

app.get('/test',(req,res)=>{
    res.send({
        test:'Testing is done'
    })
})

Below is my User.ts for entity User located in entity folder.

import {Entity , PrimaryGeneratedColumn , Column , BaseEntity } from 'typeorm'

@Entity()
export class User extends BaseEntity {
 @PrimaryGeneratedColumn()
    id!: number;

 @Column()
    name!: string;

 @Column()
    email!: string;

 @Column()
    phone!: string;

}

I am getting error like this

Error: Cannot find module './entity/User'
Require stack:
- D:\2023\elluminous\technical_growth_program\node.js\node-mysql-typeorm\app.js
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (D:\2023\elluminous\technical_growth_program\node.js\node-mysql-typeorm\app.js:2:18)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    'D:\\2023\\elluminous\\technical_growth_program\\node.js\\node-mysql-typeorm\\app.js'
  ]
}
[nodemon] app crashed - waiting for file changes before starting...

Also I have tried with

import { User } from "./entity/User"

in app.js but I am getting error like this

(node:15732) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
D:\2023\elluminous\technical_growth_program\node.js\node-mysql-typeorm\app.js:3
import { User } from "./entity/User"
^^^^^^

SyntaxError: Cannot use import statement outside a module
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1031:15)
    at Module._compile (node:internal/modules/cjs/loader:1065:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:17:47
Solution

  • You cannot mix JS and TS. In your scripts you are using nodemon app.js which means that you are starting a regular NodeJS process and it will be restarted should app.js or any imported dependencies change.

    TS cannot be executed by NodeJS and should be first transformed into JS using tsc compiler. For dev mode you would want to have it served and for that you would use ts-node which I can see in your deps but is unused in the scripts.

    To tell nodemon that you want to use TS you should change app.js to app.ts so it's using TS instead of JS. This should fix the issue.