Class-validator. Make all fields of the parent class optional

Question

I have a DTO to create a product

export class CreateProductDto {
  @IsString()
  title!: string

  @IsString()
  description!: string

  @IsString()
  url!: string

  @IsNumber()
  @Min(0)
  price!: number

  @IsArray()
  @ValidateNested({ each: true })
  @ArrayMinSize(1)
  @Type(() => ImageDto)
  images!: ImageDto[]

  @IsArray()
  @ValidateNested({ each: true })
  @ArrayMinSize(1)
  @Type(() => ProductSizeDto)
  sizes!: ProductSizeDto[]
}

I need a DTO for a product update. To avoid repeating myself I inherit from the creation dto. But I need all fields of the parent class to become @IsOptional()

export class UpdateProductDto extends CreateProductDto {
  @IsString()
  id!: string;
}

Answer 1

Sounds like a use case for PartialType from @nestjs/mapped-types. You would be able to do something like

import { PartialType } from '@nestjs/mapped-types';

export class UpdateProductDto extends PartialType(CreateProductDto) {
  @IsString()
  id!: string;
}

If you are using @nestjs/swagger you can import PartialType from @nestjs/swagger instead to keep the OpenAPI metadata for the UpdateProductsDto, as it extends the initial implementation of @nestjs/mapped-types