Does not work with decorators of `nestjs-seeder`

[MoWafy001]

Decorators of nestjs-seeder don't run when inherited.

import { Factory } from 'nestjs-seeder';
import { decorate } from 'ts-mixer';
import { Column } from 'typeorm';
import { hashPassword } from 'path-to-method';

export class HasPassword {
  @decorate(Column({ type: 'varchar' }))
  @decorate(Factory((_f) => hashPassword('password')))
  password: string;
}

export class User extends Mixin(HasPassword) {}

const user: Array<Partial<User>> = DataFactory.createForClass(User).generate(1)
// doesn't have a `password` property

In this example, the Column decorator of typeorm does work but the Factory decorator of nestjs-seeder doesn't work

[tannerntannern]

There are number of reasons this might not be working. Before I spend time on this, please help me by sharing the results of these two tests:

1. Do you get the desired behavior if you make the following replacement:

   -export class User extends Mixin(HasPassword) {}
   +export const User = Mixin(HasPassword);

2. Separately, does the issue persist if you make the following replacement:

   -export class User extends Mixin(HasPassword) {}
   +export class User extends HasPassword {}

If both of these tests answer "yes", then this would suggest to me that there's an issue with nestjs-seeder not respecting inheritance, which is completely out of ts-mixer's control. ts-mixer can track which decorators are applied to the classes you use in a mixin (HasPassword in this case) and reapply them to the mixed class. However, that's not User in this case, but rather Mixin(HasPassword). The User (class as written in your example) is outside the control of ts-mixer. It merely inherits from a ts-mixer-controlled class.

If one or both of these tests result in "no", then I'd be happy to investigate further, but that's my theory at the moment. Please let me know what you find.

Thanks!

[MoWafy001]

OK, I run 3 tests.

HasPassword Class

export class HasPassword {
  @decorate(Column({ type: 'varchar' }))
  @decorate(Factory((_f) => hashPassword('password')))
  password: string;
}

1. (OG) class extending Mixin(HasPassword) failed

class Test1 extends Mixin(HasPassword){}
const mockTest1 = DataFactory.createForClass(Test1).generate(1).shift();
console.log("mockTest1", mockTest1);
// output: mockTest1 {}

2. class extending HasPassword failed

class Test2 extends HasPassword{}
const mockTest2 = DataFactory.createForClass(Test2).generate(1).shift();
console.log("mockTest2", mockTest2);
// output: mockTest2 {}

3. const = Mixin(HasPassword) succeeded

const Test3 = Mixin(HasPassword);
const mockTest3 = DataFactory.createForClass(Test3).generate(1).shift();
console.log("mockTest3", mockTest3);
// mockTest3 {
//   password: 'hashed-password'
// }

[tannerntannern]

Thanks @MoWafy001, this does indeed confirm my theory. Number 2 in particular shows why the OG example doesn't work: nestjs-seeder doesn't respect inheritance whether ts-mixer is involved or not, so that's an issue you'd have to take up with them.