未找到元数据。可能安装了不止一次的类验证器版本。您需要扁平化您的依赖项

Question

当我运行这个命令curl -vd '{"NickName":"Marry","Password":"pwd"}' -H "Content-type: application/json" http://127.0.0.1:3000/signin时，我在服务器端打印了No metadata found. There is more than once class-validator version installed probably. You need to flatten your dependencies.，并且validate不能正确执行。在此之前，我npm install了一些依赖项：

npm install --save routing-controllers
npm install --save class-transformer
npm install --save class-validator

有人能帮帮忙吗？我该怎么解决这个问题呢?谢谢！

import { Entity, Column, PrimaryGeneratedColumn, CreateDateColumn, UpdateDateColumn } from 'typeorm';
import { Length } from 'class-validator';
import * as ErrorCode from '../error/errorcode'

@Entity()
export class User {
    @PrimaryGeneratedColumn()
    @Column({
        name: "id"
    })
    Id?: number;

    @Column({
        name: "nickname"
    })
    @Length(1, 20, {
        message: "NickName must be 1 to 20 characters",
        context: {
            errorCode: ErrorCode.ParamLengthNotInRange
        }
    })
    Nickname: string;

    @Column({
        name: "password"
    })
    @Length(6,20)
    Password: string;

    //constructor(input : { Id : number , Nickname: string, Password: string}){
    constructor(input : { Nickname: string, Password: string}){
        //this.Id = input.Id;
        this.Nickname = input.Nickname;
        this.Password = input.Password;
    }

}

import { JsonController, Post, Body, Req } from "routing-controllers";
import { validate, ValidationError } from 'class-validator';
import {User} from '../entity'

@JsonController()
export class UserController {

    @Post('/signin')
    async signin(@Body() user: User) {
        const errors: ValidationError[] = await validate(user)
        if (errors && errors.length > 0) {
            console.log(errors[0].contexts!['Length'].errorCode)
        }
        console.log(user)
        return 'this is signin'
    }
}

Answer 1

您可以通过执行以下操作来检查是否安装了更多版本的class-validator：

npm ls class-validator

在我的例子中，我使用的是type-graphql，并且发现type-graphql也在安装class-validator的早期版本。因此，我只是将package.json中的版本降级到更早的版本，以使它们匹配，然后重新安装，消息就消失了。

希望这能有所帮助。

Answer 2

我们收到了相同的信息。class-validator从0.12.2更新到0.13.1解决了这个问题。