A progressive Node.js framework for building efficient and scalable server-side applications.
NestJS Response DTO Mapper
Installation
yarn add nestjs-response-dto-mapper
Usage
- Create a DTO class using at least one
class-transformer
decorator for each field:
import { ApiProperty } from '@nestjs/swagger';
import { Expose } from 'class-transformer';
export class UserDto {
@Expose()
@ApiProperty({ description: 'ID' }) // or you can use `@nestjs/swagger` CLI plugin
id: number;
@Expose()
@ApiProperty({ description: 'First name' })
firstName: string;
@Expose()
@ApiProperty({ description: 'Last name' })
lastName: string;
@Expose()
@ApiProperty({ description: 'Email' })
email: string;
@Expose()
@ApiProperty({ description: 'Phone number' })
phone: string;
}
- Decorate each controller method with the
MapResponseToDto
decorator:
import { Controller, Get } from '@nestjs/common';
import { ApiOperation } from '@nestjs/swagger';
import { MapResponseToDto } from 'nestjs-response-dto-mapper';
import { User as UserModel } from '@prisma/client'; // for example
import { UserDto } from './dto/user.dto';
@Controller('user')
export class UserController {
@Get()
@ApiOperation({ summary: 'List all users' }) // or you can use @nestjs/swagger CLI plugin
@MapResponseToDto(UserDto, { /* ApiOkResponse decorator options */ isArray: true })
findMany(): UserModel[] {
// for example
return [
{
id: 1,
firstName: 'Example',
lastName: 'Example',
email: 'example@example.com',
phone: '+99999999999',
password: '$2y$10$gN9UIb8EjkhNWxu8iRJQOe/kAk1TqhtJ1M72DKx.BrpgyAe7XURhq',
rights: 'user'
},
{
id: 2,
firstName: 'Test',
lastName: 'Test',
email: 'test@example.com',
phone: '+88888888888',
password: '$2y$10$Mrh1URLy.Fo8tmBZtaPd5OR.1gDaPvU7GX02./uK9kKz.Skoc2C5y',
rights: 'user'
},
{
id: 3,
firstName: 'Admin',
lastName: 'Admin',
email: 'admin@example.com',
phone: '+88005553535',
password: '$2y$10$qi8oDsLM88XMw4ZStIE7pOG6yZNceqDTVOp0ajLIOk2ttyIcPF9r.',
rights: 'admin'
}
]
}
}
- Run and test it!
Swagger schema:
Response:
[
{
"id": 1,
"firstName": "Example",
"lastName": "Example",
"email": "example@example.com",
"phone": "99999999999"
},
{
"id": 2,
"firstName": "Test",
"lastName": "Test",
"email": "test@example.com",
"phone": "+88888888888"
},
{
"id": 3,
"firstName": "Admin",
"lastName": "Admin",
"email": "admin@example.com",
"phone": "+88005553535"
}
]
Troubleshooting
I use the @nestjs/swagger CLI Plugin and my method returns an array of objects, but the swagger does not display the method summary and response schema Try casting the return value to the dto type:
// controller...
export class UserController {
// ...
findMany(): UserDto[] {
// findMany returns UserModel[]
return this.userService.findMany() as UserDto[];
}
}