Nest 使用 DTO

安装

pnpm i class-validator class-transformer -S

修改 global.pipe.ts

import { PipeTransform, Injectable, ArgumentMetadata } from "@nestjs/common";
import { plainToInstance } from "class-transformer";
import { validate } from "class-validator";
// 引入我自己验证的异常类
import { GlobalCheckException } from "./globalcheck.exception";
@Injectable()
export class GlobalPipe implements PipeTransform {
  // 校验类型
  private toValidate(metatype: Function): boolean {
    // 其他类型不验证
    const types: Function[] = [String, Boolean, Number, Array, Object];
    return !types.includes(metatype);
  }
  async transform(value: any, metadata: ArgumentMetadata) {
    const { metatype } = metadata;

    if (!metatype || !this.toValidate(metatype)) {
      return value;
    }
    // 变成对象,把规则和值 组合成验证的对象
    const object = plainToInstance(metatype, value);
    // 验证 errors 是个数组
    const errors = await validate(object);

    if (errors.length > 0) {
      // 第一种只返回第一个
      if (errors.length == 1) {
        for (let arr in errors[0].constraints) {
          const result = `${errors[0].constraints[arr]}`;
          throw new GlobalCheckException(result);
        }
      }

      // 第二种返回所有
      let result: string[] = [];
      errors.forEach((item) => {
        for (let arr in item.constraints) {
          result.push(item.constraints[arr]);
        }
      });
      throw new GlobalCheckException(result.join("|"));
    }
    return value;
  }
}

新建一个 DTO

import { IsNotEmpty, MaxLength, MinLength } from "class-validator";
export class CreateUserDto {
  @MinLength(6, { message: "userId不能小于6位" })
  @IsNotEmpty({ message: "userId不能为空" })
  userId: string;

  @IsNotEmpty({ message: "userName不能为空" })
  @MaxLength(20, { message: "userName长度不能超过20位" })
  @MinLength(6, { message: "userName长度不能小于6位" })
  userName: string;
}

控制器使用

  @Post('register/jwt')
  async createJwt(@Body() body: CreateUserDto) {
    const token = await this.JwtServiceAll.setToken({
      userId: body.userId,
      userName: body.userName,
    });
    return {
      data: token,
    };
  }