如何使一组装饰器在 Typescript 中易于重用

Question

TL;DR

How to group decorators (from a library) together into 1 re-usable decorator

问题

每次我的 REST API 收到请求时，它都会验证提供的正文属性（使用 class-validator 库）。每个路由都有自己专用的验证class（在代码中它们称为 Dtos）（参见示例）

每个提供的正文属性都有一些验证规则，这些规则有时会变得非常复杂，其他工程师应该能够轻松地重复使用这些验证规则 .

例子

路线 1：创建公司

POST - /api/company
     >> Parameters: name, domain, size, contact

class CreateCompanyDto implements Dto {
    @IsString({message: 'Must be text format'})
    @MinLength(2, { message: "Must have at least 2 characters" })
    @MaxLength(20, { message: "Can't be longer than 20 characters" })
    @IsDefined({ message: 'Must specify a receiver' })
    public name!: string;

    @MaxLength(253, { message: "Can't be longer than 253 characters" })
    @IsFQDN({}, {message: 'Must be a valid domain name'})
    @IsDefined({ message: 'Must specify a domain' })
    public domain!: string;

    @MaxLength(30, { message: "Can't be longer than 30 characters" })
    @IsString({message: 'Must be text format'})
    @IsDefined({ message: 'Must specify a company size' })
    public size!: string;

    @IsPhoneNumber(null, {message: 'Must be a valid phone number'})
    @IsDefined({ message: 'Must specify a phone number' })
    public contact!: string;
}

路线 2：公司更新

PUT - /api/company
    >> Parameters: id, name, domain, size, contact

class UpdateCompanyDto implements Dto {

    @IsUUID()
    @IsDefined({ message: 'Must be defined' })
    public id!: string;

    @IsString({ message: 'Must be text format' })
    @MinLength(2, { message: "Must have at least 2 characters" })
    @MaxLength(20, { message: "Can't be longer than 20 characters" })
    @IsOptional()
    public name!: string;

    @MaxLength(253, { message: "Can't be longer than 253 characters" })
    @IsFQDN({}, { message: 'Must be a valid domain name' })
    @IsOptional()
    public domain!: string;

    @MaxLength(30, { message: "Can't be longer than 30 characters" })
    @IsString({ message: 'Must be text format' })
    @IsOptional()
    public size!: string;

    @IsPhoneNumber(null, { message: 'Must be a valid phone number' })
    @IsOptional()
    public contact!: string;
}

我在寻找什么

正如您在示例中看到的那样，一个验证 class 需要使用另一个验证 class.

的属性的情况并不少见

问题在于，如果工程师在随机验证 class 中将 1 条验证规则添加到属性，其他验证 classes 将不会动态更新。

问题：什么是最好的方法来确保一旦装饰器得到 changed/added 其他验证 classes 知道更新。

有什么方法可以将它们组合成一个 variable/decorator 吗？感谢任何 Typescript 专家的帮助！

可接受的结果：

class CreateCompanyDto implements Dto {
    @IsCompanyName({required: true})
    public name!: string;

    @IsCompanyDomain({required: true})
    public domain!: string;

    @isCompanySize({required: true})
    public size!: string;

    @isCompanyContact({required: true})
    public contact!: string;
}

class UpdateCompanyDto implements Dto {

    @IsCompanyId({required: true})
    public id!: string;

    @IsCompanyName({required: false})
    public name!: string;

    @IsCompanyDomain({required: false})
    public domain!: string;

    @isCompanySize({required: false})
    public size!: string;

    @isCompanyContact({required: false})
    public contact!: string;
}

Answer 1

由于装饰器的功能特性，您可以轻松定义自己的装饰器工厂来调用所有必需的验证器：

export function IsCompanyName({ required }: { required: boolean }): PropertyDecorator {
  return function (target: any,
    propertyKey: string | symbol): void {
    IsString({ message: 'Must be text format' })(target, propertyKey);
    MinLength(2, { message: "Must have at least 2 characters" })(target, propertyKey);
    MaxLength(20, { message: "Can't be longer than 20 characters" })(target, propertyKey);
    if (required)
      IsDefined({ message: 'Must specify a receiver' })(target, propertyKey);
    else
      IsOptional()(target, propertyKey);
  }
}

Playground

小装修厂工厂

export function ValidatorComposer(validators: PropertyDecorator[], name: string): (options: { required: boolean }) => PropertyDecorator {
  return function ({ required }: { required: boolean }) {
    return function (target: any,
      propertyKey: string | symbol): void {
      validators.forEach((validator) => validator(target, propertyKey));
      if (required)
        IsDefined({ message: 'Must specify a ' + name })(target, propertyKey);
      else
        IsOptional()(target, propertyKey);
    }
  }
}

Playground

Answer 2

您可以通过定义自己的装饰器来链接装饰器。请注意，我之前没有使用 class-validator 库，因此您需要对此进行测试。但这就是它的样子：

在这里，我定义了一个名为 IsCompanyName 的装饰器，并让它在您的示例中调用验证装饰器。我定义了 ValidationOptions 接口来传递给装饰器。是否需要此 opts 参数由您决定。如果未指定该选项，您也可以定义默认行为。在我的示例中，我将其设为可选，并使其表现得默认是必需的。只有在定义了 opts 并且 required === false 时，我才调用 IsOptional 装饰器。不然我不叫了

interface ValidationOptions {
    required?: boolean
}

function IsCompanyName(opts?: ValidationOptions) {

    return function (target: any, propertyKey: string) {
        IsString({ message: 'Must be text format' })(target, propertyKey);
        MinLength(2, { message: "Must have at least 2 characters" })(target, propertyKey);
        MaxLength(20, { message: "Can't be longer than 20 characters" })(target, propertyKey);
        IsDefined({ message: 'Must specify a receiver' })(target, propertyKey);
        if (opts && opts.required === false) {
            IsOptional()(target, propertyKey);
        }
    }
}

如何使一组装饰器在 Typescript 中易于重用

How to make a group of decorators easily reusable in Typescript

api

validation

decorator

typescript

TL;DR

问题

例子

我在寻找什么

小装修厂工厂