Documenting DTOs

src/products/dto/create-product.dto.ts

import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
import { IsIn, IsInt, IsOptional, IsPositive, IsString, Length, Min } from 'class-validator';

export class CreateProductDto {
  @ApiProperty({ example: 'boAt Airdopes 141', minLength: 3, maxLength: 120 })
  @IsString() @Length(3, 120)
  name: string;

  @ApiPropertyOptional({ example: '42 hours playback, ENx noise cancellation' })
  @IsOptional() @IsString()
  description?: string;

  @ApiProperty({ example: 1299, description: 'Price in rupees, GST included' })
  @IsPositive()
  price: number;

  @ApiProperty({ example: 120, minimum: 0 })
  @IsInt() @Min(0)
  stock: number;

  @ApiProperty({ enum: ['audio', 'mobiles', 'laptops', 'wearables', 'accessories'], example: 'audio' })
  @IsIn(['audio', 'mobiles', 'laptops', 'wearables', 'accessories'])
  category: string;
}

// update-product.dto.ts: import PartialType from @nestjs/swagger (not @nestjs/mapped-types)
// export class UpdateProductDto extends PartialType(CreateProductDto) {}