作为表达式调用时无法解析属性装饰器的签名

Question

import { isEmail, isEmpty, isPhoneNumber, Length } from "class-validator"
import { Field, InputType } from "type-graphql";

@InputType()
export class RegisterInput {
    @Field()
    @Length(2, 15, { message: "Username Must Be At Least 2 characters" })
    username?: string;

    @Field()
    @isEmail()
    email?: string;

    @Field()
    @Length(1, 20)
    @isPhoneNumber()
    phoneNumber?: string;

    @isEmpty()
    password?: string

}

问题是@isEmail() 和@isPhoneNumber() 和@isEmpty() 抛出同样的错误：

Unable to resolve signature of property decorator when called as an expression.
  This expression is not callable.
    Type 'Boolean' has no call signatures.ts(1240)

请帮帮我，我整天都被这个错误困住了

Answer 1

你必须用大写字母写那些装饰器。 TypeScript 区分大小写：

import { IsEmail, IsEmpty, IsPhoneNumber, Length } from "class-validator";

@Field()
@IsEmail()
email?: string;

@Field()
@Length(1, 20)
@IsPhoneNumber()
phoneNumber?: string;

@IsEmpty()
password?: string