Sequelize in Node.js with TypeScript - Class constructor Model cannot be invoked without 'new'

Question

I'm trying to use Sequelize in Node.js + TypeScript. I'm trying to use following simple code:

import {Sequelize, Model, DataTypes} from 'sequelize';

const sequelize = new Sequelize('base', 'user', 'pass', {dialect: 'mysql'});

class User extends Model {
}
User.init({
    id: {
        type: DataTypes.INTEGER.UNSIGNED,
        autoIncrement: true,
        primaryKey: true,
        unique: true,
    },
    login: {
        type: DataTypes.STRING(255),
        allowNull: false,
        unique: true,
    },
    password: {
        type: DataTypes.STRING(255),
        allowNull: false,
    },
}, {
    tableName: 'users',
    sequelize,
});

sequelize.sync().then(() => {
    User.create({
        login: 'aaaa',
        password: 'bbbb',
    });
});

However when trying to run compiled code, I'm getting following error:

Unhandled rejection TypeError: Class constructor Model cannot be invoked without 'new'

From what I understand, this is not a problem with sequelize: same code run as javascript code runs with no problem and creates record in database proper table. I know this is a problem with transpiling ES6 classes to ES5, however I can't get this error fixed. This is my tsconfig.json:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "outDir": "./dist",
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "module": "esnext",
    "target": "es5",
    "sourceMap": true,
    "moduleResolution": "node",
    "lib": ["es5", "dom", "esnext"],
    "jsx": "react",
    "typeRoots": ["./common/typings", "./node_modules/@types"]
  },
  "exclude": [
    "node_modules"
  ]
}

From what I've read in Stackoverflow similiar questions and various sites on internet, changing target in compiler options to ES6 should resolve problem, but even after such change problem still occurs. I'm running out of ideas what I've done wrong here, so help will be greatly appreciated.

Tomerikoo · Accepted Answer · 2021-03-05 15:25:58Z

3

Go to the tsconfig.json file. Then, change target to es6 like the sample below:

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "declaration": true,
    "outDir": "./lib",
    "strict": true
  },
  "include": ["src"],
  "exclude": ["node_modules", "**/__tests__/*"]
}

edited Mar 5, 2021 at 15:25

Tomerikoo

19.6k16 gold badges57 silver badges68 bronze badges

answered Mar 5, 2021 at 15:00

Hoang Subin

7,5608 gold badges42 silver badges58 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

aaronmbmorse Over a year ago

This worked for me. Originally I had it set as es5.

Ionel Lupu Over a year ago

I used ES6 or ESNext and I still get this error

Nick Chibuikem · Accepted Answer · 2020-11-08 00:24:51Z

2

try changing target to "ES2017" in tsconfig.json. solved the proplem for me.

answered Nov 8, 2020 at 0:24

Nick Chibuikem

363 bronze badges

1 Comment

Nick Chibuikem Over a year ago

its in the root directory, it's called tsconfig.json. it's where you put typescript configuration settings.

Nikolay Podolnyy · Accepted Answer · 2021-09-01 11:06:14Z

0

Thanks to https://stackoverflow.com/users/4344732/tran-son-hoang, I've solved issues after adding "module": "commonjs" to tsconfig.josn

"compilerOptions": {
    ...
    "module": "commonjs",
    ...
  },

answered Sep 1, 2021 at 11:06

Nikolay Podolnyy

1,10112 silver badges19 bronze badges

Collectives™ on Stack Overflow

Sequelize in Node.js with TypeScript - Class constructor Model cannot be invoked without 'new'

3 Answers 3

2 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related