@anatine/zod-nestjs

Helper methods for using Zod in a NestJS project.

• Validation pipe on data
• Patch to Swagger module

---

Installation

@anatine/zod-openapi, openapi3-ts, and zod are peer dependencies instead of dependant packages. While zod is necessary for operation, openapi3-ts is for type-casting. @anatine/zod-openapi does the actual conversion

1npm install openapi3-ts zod @anatine/zod-openapi @anatine/zod-nestjs 

---

Usage

Generate a schema

Use Zod to generate a schema. Additionally, use @anatidae/zod-openapi to extend a schema for OpenAPI and Swagger UI.

Example schema:

1import { createZodDto } from '@anatine/zod-nestjs';
2import { extendApi } from '@anatine/zod-openapi';
3import { z } from 'zod';
4export const CatZ = extendApi(
5  z.object({
6    name: z.string(),
7    age: z.number(),
8    breed: z.string(),
9  }),
10  {
11    title: 'Cat',
12    description: 'A cat',
13  }
14);
15export class CatDto extends createZodDto(CatZ) {}
16export class UpdateCatDto extends createZodDto(CatZ.omit({ name: true })) {}
17export const GetCatsZ = extendApi(
18  z.object({
19    cats: extendApi(z.array(z.string()), { description: 'List of cats' }),
20  }),
21  { title: 'Get Cat Response' }
22);
23export class GetCatsDto extends createZodDto(GetCatsZ) {}
24export const CreateCatResponseZ = z.object({
25  success: z.boolean(),
26  message: z.string(),
27  name: z.string(),
28});
29export class CreateCatResponseDto extends createZodDto(CreateCatResponseZ) {}
30export class UpdateCatResponseDto extends createZodDto(
31  CreateCatResponseZ.omit({ name: true })
32) {}

Use the schema in your controller

This follows the standard NestJS method of creating controllers.

@nestjs/swagger decorators should work normally.

Example Controller

1import { ZodValidationPipe } from '@anatine/zod-nestjs';
2import {
3  Body,
4  Controller,
5  Get,
6  Param,
7  Patch,
8  Post,
9  UsePipes,
10} from '@nestjs/common';
11import { ApiCreatedResponse } from '@nestjs/swagger';
12import {
13  CatDto,
14  CreateCatResponseDto,
15  GetCatsDto,
16  UpdateCatDto,
17  UpdateCatResponseDto,
18} from './cats.dto';
19@Controller('cats')
20@UsePipes(ZodValidationPipe)
21export class CatsController {
22  @Get()
23  @ApiCreatedResponse({
24    type: GetCatsDto,
25  })
26  async findAll(): Promise<GetCatsDto> {
27    return { cats: ['Lizzie', 'Spike'] };
28  }
29  @Get(':id')
30  @ApiCreatedResponse({
31    type: CatDto,
32  })
33  async findOne(@Param() { id }: { id: string }): Promise<CatDto> {
34    return {
35      name: `Cat-${id}`,
36      age: 8,
37      breed: 'Unknown',
38    };
39  }
40  @Post()
41  @ApiCreatedResponse({
42    description: 'The record has been successfully created.',
43    type: CreateCatResponseDto,
44  })
45  async create(@Body() createCatDto: CatDto): Promise<CreateCatResponseDto> {
46    return {
47      success: true,
48      message: 'Cat created',
49      name: createCatDto.name,
50    };
51  }
52  @Patch()
53  async update(
54    @Body() updateCatDto: UpdateCatDto
55  ): Promise<UpdateCatResponseDto> {
56    return {
57      success: true,
58      message: `Cat's age of ${updateCatDto.age} updated`,
59    };
60  }
61}

NOTE: Responses have to use the ApiCreatedResponse decorator when using the @nestjs/swagger module.

Set up your app

Patch the swagger so that it can use Zod types before you create the document.

Example Main App

1import { Logger } from '@nestjs/common';
2import { NestFactory } from '@nestjs/core';
3import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
4import { CatsModule } from './app/cats.module';
5import { patchNestjsSwagger } from '@anatine/zod-nestjs';
6async function bootstrap() {
7  const app = await NestFactory.create(CatsModule);
8  const globalPrefix = 'api';
9  app.setGlobalPrefix(globalPrefix);
10  const config = new DocumentBuilder()
11    .setTitle('Cats example')
12    .setDescription('The cats API description')
13    .setVersion('1.0')
14    .addTag('cats')
15    .build();
16  patchNestjsSwagger(); // <--- This is the hacky patch using prototypes (for now)
17  const document = SwaggerModule.createDocument(app, config);
18  SwaggerModule.setup('api', app, document);
19  const port = process.env.PORT || 3333;
20  await app.listen(port, () => {
21    Logger.log('Listening at http://localhost:' + port + '/' + globalPrefix);
22  });
23}
24bootstrap();

Future goals

• Remove dependency on @nestjs/swagger by providing a Swagger UI.
• Expand to create an express-only wrapper (without NestJS)
• Auto generate client side libs with Zod validation.

Credits

• zod-dto

  Extensive use and inspiration from zod-dto.