Nest.js 实战 (四)：利用 Pipe 管道实现数据验证和转换

 pnpm add class-validator class-transformer

 import { ArgumentMetadata, BadRequestException, Injectable, PipeTransform } from '@nestjs/common';
 import { plainToClass } from 'class-transformer';
 import { validate } from 'class-validator';

 @Injectable()
 export class ValidationPipe implements PipeTransform {
   async transform(value: any, { metatype }: ArgumentMetadata) {
     if (!metatype || !this.toValidate(metatype)) {
       // 如果没有传入验证规则，则不验证，直接返回数据
       return value;
     }
     // 将对象转换为 Class 来验证
     const object = plainToClass(metatype, value);
     const errors = await validate(object);
     if (errors.length > 0) {
       const msg = Object.values(errors[0].constraints)[0]; // 只需要取第一个错误信息并返回即可
       // 自定义校验返回格式
       throw new BadRequestException(`参数校验失败: ${msg}`);
     }
     return value;
   }
   private toValidate(metatype: any): boolean {
     const types: any[] = [String, Boolean, Number, Array, Object];
     return !types.includes(metatype);
   }
 }

 import { NestFactory } from '@nestjs/core';
 import { ValidationPipe } from '@/pipe/validation.pipe'; // 全局管道

 import { AppModule } from './app.module';
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);

   // 全局参数校验
   app.useGlobalPipes(new ValidationPipe());

   await app.listen(3000);
 } 
 bootstrap();

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

export class SavePostDto {
  @ApiProperty({
    type: String,
    description: '父级id',
    default: '0c01ef7d-2f6f-440a-b642-62564d41f473',
    required: false,
  })
  @IsOptional()
  @IsUUID('all', { message: 'parentId 参数不正确' })
  parentId?: string;

  @ApiProperty({
    type: String,
    description: '岗位名称',
    default: '前端工程师',
  })
  @IsNotEmpty({ message: '岗位名称必填' })
  name: string;

  @ApiProperty({
    type: String,
    description: '组织id',
    default: 'f45cd48b-e703-49db-91be-ae7f594e73e0',
  })
  @IsUUID('all', { message: 'orgId 参数不正确' })
  orgId: string;

  @ApiProperty({
    type: Number,
    description: '排序',
    default: 1,
  })
  @IsNumber(
    {},
    {
      message: '排序必须为数字',
    },
  )
  sort: number;

  @ApiProperty({
    type: String,
    description: '岗位描述',
    default:
      '前端工程师是互联网时代软件产品研发中不可缺少的一种专业研发角色。从狭义上讲，前端工程师使用 HTML、CSS、JavaScript 等专业技能和工具将产品UI设计稿实现成网站产品，涵盖用户PC端、移动端网页，处理视觉和交互问题。',
    required: false,
  })
  describe?: string;
}

import { Body, Controller, Get, ParseUUIDPipe} from '@nestjs/common';
import { ApiOkResponse, ApiOperation, ApiTags } from '@nestjs/swagger'; // swagger 接口文档

import { ResponseSavePostDto } from './dto/response-post.dto';
import { PostManageService } from './post-manage.service';

@ApiTags('智能行政-岗位管理')
@Controller('post-manage')
export class PostManageController {
  constructor(private readonly postManageService: PostManageService) { }

  /**
   * @description: 查询岗位详情
   */
  @Get(':id')
  @ApiOkResponse({ type: ResponseSavePostDto })
  @ApiOperation({ summary: '查询岗位详情' })
  findOne(@Param('id', new ParseUUIDPipe()) id: string) {
    return this.postManageService.findOne(id);
  }
}