dto-standards.md

DTO Standards

Base Structure

import { IsString, IsNotEmpty, IsOptional } from 'class-validator';
import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';

export class CreateModuleDto {
  @ApiProperty({ description: 'Field description' })
  @IsString()
  @IsNotEmpty()
  name: string;

  @ApiPropertyOptional({ description: 'Optional field' })
  @IsString()
  @IsOptional()
  description?: string;
}

Validation

• Use class-validator decorators
• @IsString(), @IsNumber(), @IsEmail(), etc.
• @IsNotEmpty() for required fields
• @IsOptional() for optional fields
• @Min(), @Max() for numeric ranges

Swagger Documentation

• @ApiProperty() for required fields
• @ApiPropertyOptional() for optional fields
• Include description in all fields
• Use example when useful

Transformation

• Use class-transformer for transformations
• @Transform() for custom transformations
• @Exclude() to exclude fields from responses

Conventions

• Name: {Action}{Entity}Dto
• Request: CreateLoanDto, UpdateUserDto
• Response: LoanResponseDto, UserResponseDto
• File: {action}-{entity}.dto.ts

Wallet Validation

@IsString()
@Matches(/^G[A-Z0-9]{55}$/, { message: 'Invalid Stellar wallet address' })
wallet: string;