Bug in manual validation of i18n service, when validating nested object?

[heken84]

Hi there,

I have a problem with the validation method "i18n.validate" from the "I18nService" while validating nested objects. I always get an "TypeError: Cannot convert undefined or null to object\n

This error does not occur, when I use the normal "validate" function of the "class-validator" library. Here I get the correct errors, but of course with missing translations.

I hope someone can help me. Maybe there is a bug in the "I18nService"?

Thank you,
Heiko

---

My Dto (Parent)

export class RestrictionCodeDto {

  @IsNotEmpty({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isNotEmptyError') })
  @Validate(hasRestrictionCodeValidLength, { message: i18nValidationMessage<I18nTranslations>('messages.validation.rcLengthError') })
  id: string;

  @IsNotEmpty({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isNotEmptyError') })
  @IsString({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isStringError') })
  @Length(4, 4, { each: true, message: i18nValidationMessage<I18nTranslations>('messages.validation.lengthError') })
  salesOrganization: string;

  @Type(() => Boolean)
  @IsBoolean({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isBooleanError') })
  active: boolean

  @Type(() => Boolean)
  @IsBoolean({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isBooleanError') })
  defectMaingroupRequired: boolean;

  @IsNotEmpty({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isNotEmptyError') })
  @IsString({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isStringError') })
  @Length(7, 7, { message: i18nValidationMessage<I18nTranslations>('messages.validation.lengthError') })
  changedBy: string;

  @IsOptional()
  @Type(() => Date)
  @IsDate({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isDateError') })
  lastChangeOn: Date | null;

  @ValidateNested({each: true})
  @Type(() => RestrictionCodeTextDto)
  texts: RestrictionCodeTextDto [];
}

My Dto (Nested)

export class RestrictionCodeTextDto {
  
  @IsString({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isStringError') })
  @Length(2, 2, { message: i18nValidationMessage<I18nTranslations>('messages.validation.lengthError') })
  language: string;

  @IsString({ message: i18nValidationMessage<I18nTranslations>('messages.validation.isStringError') })
  @MaxLength(200, { message: i18nValidationMessage<I18nTranslations>('messages.validation.maxLengthError') })
  text: string;
}

My Pipe

@Injectable()
export class RestrictionCodePipe implements PipeTransform {

  constructor(private i18n: I18nService) { }

  async transform(value: any, { metatype }: ArgumentMetadata) {
    const appException: AppException = new AppException(HttpStatus.BAD_REQUEST, []);

    const restrictionCodeDto: RestrictionCodeDto = plainToInstance(metatype, value);

    // this method throws the stack trace
    const errors: I18nValidationError[] = await this.i18n.validate( 
      restrictionCodeDto, { lang: I18nContext.current().lang }
    );

   // processing of errors
  }
}

Stack Trace

{"TypeError: Cannot convert undefined or null to object\n    at Function.keys (<anonymous>)\n    at ...node_modules\\nestjs-i18n\\src\\utils\\util.ts:79:32\n    at Array.map (<anonymous>)\n    at formatI18nErrors (...node_modules\\nestjs-i18n\\src\\utils\\util.ts:64:17)\n    at ...\\node_modules\\nestjs-i18n\\src\\utils\\util.ts:78:22\n    at Array.map (<anonymous>)\n    at formatI18nErrors (...\\node_modules\\nestjs-i18n\\src\\utils\\util.ts:64:17)\n    at I18nService.validate (...\\node_modules\\nestjs-i18n\\src\\services\\i18n.service.ts:361:28)\n    at processTicksAndRejections (node:internal/process/task_queues:95:5)\n    at RestrictionCodePipe.transform (...\\src\\rc-maintenance\\pipes\\restriction-code.pipe.ts:19:43)"}