invoice.dto.ts

import { ContractorDto } from './contractor.dto';
import { IncomeDto } from './income.dto';
import { ExpensesDto } from './expenses.dto';
import {
  IdValidator,
  PositionValidator,
  DateOfEventValidator,
  DescriptionValidator,
  RegistryValidator,
  ContractorValidator,
  IncomeValidator,
  ExpensesValidator,
} from '../helpers/invoiceValidation.decorator';

export class InvoiceDto {
  @IdValidator() id: string;
  @PositionValidator() position: number;
  @DateOfEventValidator() dateOfEvent: string;
  @RegistryValidator() registry: string;
  @DescriptionValidator() description: string;
  @ContractorValidator() contractor: ContractorDto;
  @IncomeValidator() income: IncomeDto;
  @ExpensesValidator() expenses: ExpensesDto;
}

invoices.controller.ts

  type XYZ = Omit<InvoiceDto, 'id'>;

  @Post('/add')
  addInvoice(
    @Res() res: Response,
    @Body(
      new ValidationPipe({
        transform: true,
        disableErrorMessages: false,
        always: true,
        stopAtFirstError: true,
        validateCustomDecorators: true,
        skipMissingProperties: false,
      }),
    )
    body: XYZ, // here is a problem, when I'm using InvoiceDto - validation works, but when i try to use Omit it doesnt work
  ) {
    // I dont neet to validate ID field because I will generate it on backend
    const invoice = this.invoicesService.addInvoice(body);
    return res.json(invoice);
  }

invoiceValidation.decorator.ts

export function IdValidator() {
  return applyDecorators(
    IsDefined({ message: 'ID of an inovice is required!' }),
    IsString({ message: 'ID must be a string!' }),
    Length(21, 21, { message: 'ID is not valid!' }),
  );
}

export function PositionValidator() {
  return applyDecorators(
    IsDefined({ message: 'Position of invoice is required!' }),
    IsNotEmpty(),
    IsInt({ message: 'Position of invoice must be a number' }),
    Min(1, { message: 'Position of invoice must be greater than 0' }),
  );
}

export function DateOfEventValidator() {
  return applyDecorators(
    IsDefined({ message: 'Date of invoice event is required!' }),
    IsOnlyDate(),
  );
}

// I've just add a couple of validators