Sequelize: Class constructor Model cannot be invoked without 'new' and how getter v4 work?

[zonorion]

Hi all,
I using v4 to defined my model as:

@Options({
    sequelize,
    tableName: 'V2_category',
    timestamps: false
})
@Attributes({
    id: {
        type: DataTypes.INTEGER,
        allowNull: false,
        primaryKey: true,
        autoIncrement: true
    },
    name: DataTypes.STRING,
    name_vi: DataTypes.STRING,
    code: DataTypes.STRING,
    type: DataTypes.STRING,
    created_at: DataTypes.DATE,
    updated_at: DataTypes.DATE,
})
export class V2Category extends Model {
    get fullName() {
        return this.name + '-' + this.name_vi;
    }

    set fullName(fullName) {
        const names = fullName.split(' ');
        this.name = names.pop();
        this.name_vi = names.join(' ');
    }
}

and i import in others:
import {V2Category as category} from '../models/V2_category';

my query :
findCategoryById (id) { return category.findOne({ where: { 'id': id } }); }

When run i got an error:

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

However, i add { where: { 'id': id }, raw: true } my code working but i can't use getter function fullName. Could you tell me where my mistake and how to fix it? Thanks

[felixfbecker]

Please post the whole stack trace

[kalyuk]

I had the same problem

During debugging I found out that the Model constructor returns a class instead of a function

I have a suspicion that the problem arises at the moment of inheritance

[felixfbecker]

In JavaScript, a class is a function.

[kalyuk]

@felixfbecker nice joke, I'm very familiar with JS
I could not understand why he inherited this error when he inherited
But if you go the old way and use define, the error disappears
static build(values, options) {
if (Array.isArray(values)){
return this.bulkBuild(values, options);
}
return new this(values, options); }`

[HriBB]

I have the same problem.

[HriBB]

I think it has something to do with the way babel transpiles the code. After I changed my .babelrc file to this:

{
  "presets": [
    ["env", {
      "targets": {
        "node": "current"
      }
    }]
  ]
}

it works as expected.

[felixfbecker]

Yes, that is very likely.
@zonorion could you post the transpiled JS of that model?

[SuperPaintman]

Intypescript case, my solution was to change target from es5 to es6

{
  "compilerOptions": {
    "target": "es6", // <=
    // ...
  }
}

[tybro0103]

I'm getting this as well. Just upgraded from 3 to 4.4.2, and when I change my model definitions to:

const attributes = {/*...*/};
const options = {
  sequelize,
};
class User extends Sequelize.Model {
  someInstanceMethod() {}
}
User.someStaticMethod = () => {};
User.init(attributes, options);

I started seeing the error anytime Sequelize attempted to create an instance of User (such as User.findOne()).

My .babelrc:

{
  "presets": ["es2015", "react", "stage-0"]
}

Switching to this for now:

const User = sequelize.define('User', attributes, options);
User.prototype.someInstanceMethod = function() {}; // function can't be () => {}
User.someClassMethod = () => {};

[cinic]

@juhaelee says:

You just need to use the env preset package instead of es2015
```{
"presets": [
["env", {
"targets": {
"node": "current"
}
}],
"stage-1"
],
"plugins": []
}

[zonorion]

Sr, i missed any notifications
I used:
{ "presets": [ "es2015-node6", "stage-3" ], "plugins": [ ["transform-decorators-legacy"], [ "transform-runtime", { "polyfill": false, "regenerator": true } ], [ "istanbul", { "exclude": [ "test/*.js" ] } ] ] }

sequelize woking fine!

[BjarkeNL]

It turns out that an ES6-class transpiled by babel can't extend a real ES6 class (The Sequelize.Model ES6-class for example).

So class MyEntity extends Sequelize.Model { ... } won't work if MyEntity is transpiled into ES5.

See https://stackoverflow.com/questions/36577683/babel-error-class-constructor-foo-cannot-be-invoked-without-new

The solution i used, was to use es2015-node5 instead of es2015. But ONLY on the server, of course, not on the client - i.e. not when transpiling for the browser. So i didn't put this in my .babelrc, but added it to the "build-server" command-line scripts in package.json instead: babel .... --no-babelrc --presets=es2015-node5,stage-0,react.

[corneliouzbett]

have almost the same problem how do i solve it ... looking for a solution

[kalyuk]

@corneliouzbett

have almost the same problem how do i solve it ... looking for a solution

do you found solution ?

[christopher4lis]

I'm getting this error as well when using some of the example code listed within Express / Sequelize setup. Seems the the offending line of code is within the cli's default generated models/index.js

const model = sequelize['import'](path.join(__dirname, file))

Altered things with babel and so forth, but haven't gotten it working just yet.

[christopher4lis]

Turns out in my case, I had a previously created model in the models folder that was causing things to break:

const Sequelize = require('sequelize')
const db = require('../sequelize')

const Post = db.define('post', {
    title: Sequelize.STRING(255),
    body: Sequelize.TEXT('long'),
    excerpt: Sequelize.STRING(500),
    tags: Sequelize.STRING(500),
    slug: Sequelize.STRING(255),
    thumbnail_path: Sequelize.STRING(255),
    hero_path: Sequelize.STRING(255),
    updatedAt: Sequelize.DATE
})

module.exports = Post

This was preventing the file from being read correctly by sequelize and causing the error listed in this thread. Advice for others: Make sure all of your code inside of your models folder is valid and from examples.

[mschipperheyn]

For those running into this, this is a bug in babel. I haven't been able to solve it on my end using the suggested solutions likely because I use babel runtime transformations. There is a PR open @babel to resolve this. Hopefully it will be merged soon. https://github.com/babel/babel/pull/8656

[cpkenn09y]

Mine got solved via:

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "targets": {
          "node": true
        }
      }
    ]
  ]
}

[jcfinnerup]

Im not using a transpiler and i have this error as well

[TidyIQ]

Same issue here and my .babelrc is:

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "targets": {
          "node": "current"
        }
      }
    ]
  ]
}

Any other suggestions to solve this?

[damien-git]

Just in case it helps someone else: in my case the issue was that I was using --presets @babel/preset-env with the babel command, so my babel.config.js file with presets: [['@babel/preset-env', {targets: {node: 'current'}}]] was being ignored...

[duckbrain]

For anyone having trouble with this using Jest and Expo (React Native), you may need to add sequelize to to the transformIgnorePatterns in the jest config.

My jest.config.js

module.exports = {
  preset: "jest-expo",
  reporters: [
    "default",
    [
      "./node_modules/jest-html-reporters",
      {
        filename: "./public/test-report.html",
        pageTitle: "BioPointe: Unit Tests",
      },
    ],
  ],
  coverageDirectory: "./public/coverage",
  snapshotSerializers: ["./src/BioPointe.serializer.js"],
  transformIgnorePatterns: [
    "node_modules/(?!((jest-)?" +
      // If having issues with complation/runtime in tests regarding language
      // features, you may want to add entries to this array for the relevant
      // modules.
      [
        "react-native",
        "react-clone-referenced-element",
        "expo(nent)?",
        "@unimodules/.*",
        "jest-expo/.*",
        "@expo(nent)?/.*",
        "react-navigation",
        "@react-navigation/.*",
        "sentry-expo",
        "sequelize",
        "native-base",
        "@sentry/.*",
        "unimodules-.*",
      ].join("|") +
      "))",
  ],
};

[acharb]

For anyone who comes to this and the reason was not transpiling. For me it was because I was exporting my models as classes, and the line from the generated models/index.js :

const model = sequelize['import'](path.join(__dirname, file))

was causing the error. Once I changed that line to:

let model = require(path.join(__dirname, file));

It was fixed

[kimcuong060498]

Hi guys, I have the same issue with tsc (TypeScript compiler).

tscconfig.json

{
  "compilerOptions": {
    "target": "ES6",
    "module": "CommonJS",
    "moduleResolution": "node",
    "lib": ["ES5", "ES6"],
    "declaration": true,
    "outDir": "./build",
    "strict": true,
    "esModuleInterop": true,
    "allowJs": false,
    "allowSyntheticDefaultImports": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "strictPropertyInitialization": false,
    "sourceMap": true
  },
  "include": ["src"],
  "exclude": ["node_modules"]
}

version

{
  "sequelize": "^5.21.6",
  "ts-node": "^8.10.1",
  "typescript": "^3.7.2"
}

model

import { Model, DataTypes } from 'sequelize';
import sequelize from './';
import { OrderStatus } from '../components/constants';

class Order extends Model {
  public id!: number;
  public total!: number;
  public finalTotal!: number;
  public status: OrderStatus;
  public start_date: Date;
  public end_date: Date;
  public created_at: Date;
  public updated_at: Date;
}

Order.init({
  id: {
    type: DataTypes.UUID,
    primaryKey: true,
    defaultValue: DataTypes.UUIDV4
  },
  total: {
    type: DataTypes.INTEGER,
    allowNull: true,
  },
  finalTotal: {
    type: DataTypes.INTEGER,
    allowNull: true,
    validate: {
      len: {
        args: [2, 5],
        msg: 'Name must be from 2 to 5 characters in length'
      },
    }
  },
  status: {
    type: DataTypes.ENUM(OrderStatus.InProcess, OrderStatus.Done)
  },
}, {
  sequelize,
  tableName: 'orders',
})

export default Order;

sequelize.import

const modelsPath = `${__dirname}/../src/models`;
  const models = fs
    .readdirSync(modelsPath)
    .filter((filename: string) => /model.ts$/.test(filename))
    .reduce((total: any, filename: string) => {
      const model = sequelize.import(path.join(modelsPath, filename));
      total[capitalize(model.name)] = model;
      return total;
    }, {});

  // Sets up the associations for each model.
  Object.keys(models).forEach((modelName: string) => {
    if ('associate' in models[modelName]) {
      models[modelName].associate(models);
    }
  });

error

TypeError: Class constructor Order cannot be invoked without 'new'
      at Sequelize.import (node_modules/sequelize/lib/sequelize.js:486:38)
      at /home/cuongw/Workspace/SaveMoney/service-template/test/utils.ts:18:37
      at Array.reduce (<anonymous>)
      at Object.exports.prepareModels (test/utils.ts:17:6)
      at Object.exports.loadFixtures (test/utils.ts:35:18)
      at Context.<anonymous> (test/order.test.ts:16:11)
      at processImmediate (internal/timers.js:456:21)

Please tell me a solution. Thank all.

[svfreitas]

I had the same error with typescript and it was fixed when I updated the tsconfig.json changing the es5 for es6

"compilerOptions": {
"target": "es6", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. /
"module": "commonjs", / Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */

[kimcuong060498]

I had the same error with typescript and it was fixed when I updated the tsconfig.json changing the es5 for es6

"compilerOptions": {
"target": "es6", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. _/ "module": "commonjs", /_ Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */

Thank for your reply. I used ES6 for target but it doesn't work.

[kimcuong060498]

Hi guys, I have the same issue with tsc (TypeScript compiler).

tscconfig.json

{
  "compilerOptions": {
    "target": "ES6",
    "module": "CommonJS",
    "moduleResolution": "node",
    "lib": ["ES5", "ES6"],
    "declaration": true,
    "outDir": "./build",
    "strict": true,
    "esModuleInterop": true,
    "allowJs": false,
    "allowSyntheticDefaultImports": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "strictPropertyInitialization": false,
    "sourceMap": true
  },
  "include": ["src"],
  "exclude": ["node_modules"]
}

version

{
  "sequelize": "^5.21.6",
  "ts-node": "^8.10.1",
  "typescript": "^3.7.2"
}

model

import { Model, DataTypes } from 'sequelize';
import sequelize from './';
import { OrderStatus } from '../components/constants';

class Order extends Model {
  public id!: number;
  public total!: number;
  public finalTotal!: number;
  public status: OrderStatus;
  public start_date: Date;
  public end_date: Date;
  public created_at: Date;
  public updated_at: Date;
}

Order.init({
  id: {
    type: DataTypes.UUID,
    primaryKey: true,
    defaultValue: DataTypes.UUIDV4
  },
  total: {
    type: DataTypes.INTEGER,
    allowNull: true,
  },
  finalTotal: {
    type: DataTypes.INTEGER,
    allowNull: true,
    validate: {
      len: {
        args: [2, 5],
        msg: 'Name must be from 2 to 5 characters in length'
      },
    }
  },
  status: {
    type: DataTypes.ENUM(OrderStatus.InProcess, OrderStatus.Done)
  },
}, {
  sequelize,
  tableName: 'orders',
})

export default Order;

sequelize.import

const modelsPath = `${__dirname}/../src/models`;
  const models = fs
    .readdirSync(modelsPath)
    .filter((filename: string) => /model.ts$/.test(filename))
    .reduce((total: any, filename: string) => {
      const model = sequelize.import(path.join(modelsPath, filename));
      total[capitalize(model.name)] = model;
      return total;
    }, {});

  // Sets up the associations for each model.
  Object.keys(models).forEach((modelName: string) => {
    if ('associate' in models[modelName]) {
      models[modelName].associate(models);
    }
  });

error

TypeError: Class constructor Order cannot be invoked without 'new'
      at Sequelize.import (node_modules/sequelize/lib/sequelize.js:486:38)
      at /home/cuongw/Workspace/SaveMoney/service-template/test/utils.ts:18:37
      at Array.reduce (<anonymous>)
      at Object.exports.prepareModels (test/utils.ts:17:6)
      at Object.exports.loadFixtures (test/utils.ts:35:18)
      at Context.<anonymous> (test/order.test.ts:16:11)
      at processImmediate (internal/timers.js:456:21)

Please tell me a solution. Thank all.

I resolved my issue. I used require instead of sequelize.import. 😓

[marcosAJS]

Intypescript case, my solution was to change target from es5 to es6

{
  "compilerOptions": {
    "target": "es6", // <=
    // ...
  }
}

Works for me! Thanks

[yungnoey]

let model = require(path.join(__dirname, file))

I am having the same issue, changed the appropriate line, still no luck.

[AlexStiyer]

After much searching I found that this error does sometimes occur when the entity column type cannot be inferred.

These are the only values that can automap:
string | STRING
boolean | BOOLEAN
number | INTEGER
bigint | BIGINT
Date | DATE
Buffer | BLOB

If you are using any other value, for example a UUID you need to set that in the column annotation
@Column({type: DataType.UUIDV4})

Hope that helps anyone else going down this rabbit hole.