Injected repository on ValidatorConstraintInterface returns undefined

Question

Good night everyone, I'm working on a NestJs project, attempting to use a custom validator which requires using a repository. Right now the repository is undefined when I call the validate method, I don't finish to understand decorators and frankly a big part of NestJs/Typescript as well...

These are my current call to the validation method:

  @IsString()
  @Matches(/^([a-zA-Z0-9 _-]+)$/, {
    message:
      'Please use only letters, numbers, - symbol, or _ symbol when creating a username',
  })
  @UsernameAlreadyExists({
    message: 'Username $value already exist, please choose another username.',
  })
  username: string;

And this is my definition of the Validator Class extending ValidatorConstraintInterface:

  registerDecorator,
  ValidationOptions,
  ValidatorConstraint,
  ValidatorConstraintInterface,
  ValidationArguments,
} from 'class-validator';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './user.entity';

@ValidatorConstraint({ async: true })
export class UsernameAlreadyExistsConstraint
  implements ValidatorConstraintInterface
{
  constructor(
    @InjectRepository(User)
    private userRepository: Repository<User>,
  ) {}

  validate(userName: any, args: ValidationArguments) {
    console.log(userName, this.userRepository, this);
    return this.userRepository
      .findOneBy({ username: userName })
      .then((user) => {
        if (user) return false;
        return true;
      });
  }
}

export function UsernameAlreadyExists(validationOptions?: ValidationOptions) {
  return function (object: unknown, propertyName: string) {
    registerDecorator({
      target: object.constructor,
      propertyName: propertyName,
      options: validationOptions,
      constraints: [],
      validator: UsernameAlreadyExistsConstraint,
    });
  };
}

I can't understand the reason for it to not be working, I wasn't able to find solutions other than deprecated (it seems to me at least) solutions like using

useContainer(app, { fallback: true });

Which, anyways, did not solve my issue

Thank you guys :)

Injected repository on ValidatorConstraintInterface returns undefined

0 Answers0