Class Validator node.js提供自定义错误

我创建了一个自定义验证器约束和注释，用于检查具有给定属性的实体是否已经存在，下面是代码

import { Inject, Injectable } from '@nestjs/common';
import { registerDecorator, ValidationArguments, ValidationOptions, ValidatorConstraint } from 'class-validator';
import { ValidatorConstraintInterface } from 'class-validator/types/validation/ValidatorConstraintInterface';
import { Connection } from 'typeorm';
import { InjectConnection } from '@nestjs/typeorm';

@ValidatorConstraint({ async: true })
@Injectable()
export class EntityExistsConstraint implements ValidatorConstraintInterface {

  constructor(@InjectConnection() private dbConnection: Connection) {
  }

  defaultMessage(validationArguments?: ValidationArguments): string {
    return `${validationArguments.constraints[0].name} with ${validationArguments.property} already exists`;
  }

  validate(value: any, validationArguments?: ValidationArguments): Promise<boolean> | boolean {
    const repoName = validationArguments.constraints[0];
    const property = validationArguments.property;
    const repository = this.dbConnection.getRepository(repoName);
    return repository.findOne({ [property]: value }).then(result => {
      return !result;
    });
  }

}

export function EntityExists(repoName, validationOptions?: ValidationOptions) {
  return function(object: any, propertyName: string) {
    registerDecorator({
      target: object.constructor,
      propertyName: propertyName,
      options: validationOptions,
      constraints: [repoName],
      validator: EntityExistsConstraint,
    });
  };
}

---

我希望错误是Conflict Exception=>statusCode 409，如何实现这一点？

类验证程序对http代码没有任何作用。它只验证并返回错误列表或空数组

您需要做的是检查您使用的框架，我假设它是nestjs或路由控制器

对于路由控制器，您需要在中间件之后编写自己的，并禁用默认中间件（它将验证错误转换为400个错误请求）。 更多信息请点击此处：

对于nestjs，步骤相同。 您可以在此处找到更多信息：

{
    "statusCode": 400,
    "message": [
        "User with email already exists"
    ],
    "error": "Bad Request"
}