Как вернуть сервис в кастомном валидаторе nestjs?

Question

[Денис Самофалов]

Не понимаю что нужно прописать что-бы в валидаторе вернуть сервис categoryService из модуля category

import { registerDecorator, ValidationOptions, ValidatorConstraint, ValidatorConstraintInterface } from 'class-validator';
import { CategoryService } from 'src/modules/category/category.service';

@ValidatorConstraint({ async: true })
export class IsUniqueConstraint implements ValidatorConstraintInterface {
  constructor(private readonly categoryService: CategoryService) {}

  async validate(value: any, args: any) {

    console.log(this.categoryService) // - undefined

    return false;
  }
}

export function IsUnique(model: string, field: string, validationOptions?: ValidationOptions) {
  return function (object: Record<string, any>, propertyName: string) {
    registerDecorator({
      target: object.constructor,
      propertyName: propertyName,
      options: validationOptions,
      constraints: [model, field],
      validator: IsUniqueConstraint,
    });
  };
}

Answer 1

[Александр Мурашкин]

1)

import {useContainer, Validator} from "class-validator";

useContainer(Container);

2) используем useContainer из nest

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  useContainer(app.select(AppModule), { fallbackOnErrors: true });
...}

3) навешиваем декоратор injectable

import {ValidatorConstraint, ValidatorConstraintInterface} from 'class-validator';
import {UsersService} from './user.service';
import {Injectable} from '@nestjs/common';

@ValidatorConstraint({ name: 'isUserAlreadyExist', async: true })
@Injectable() // this is needed in order to the class be injected into the module
export class IsUserAlreadyExist implements ValidatorConstraintInterface {
    constructor(protected readonly usersService: UsersService) {}

    async validate(text: string) {
        const user = await this.usersService.findOne({
            email: text
        });
        return !user;
    }
}

4) и провайдим constraint

@Module({
    controllers: [UsersController],
    providers: [IsUserAlreadyExist, UsersService],
    imports: [],
    exports: []
})
export class UserModule {
}