plainToClass 不会将日期转换为字符串

Question

根据 the docs，Date 对象应转换为 string：

Note, that dates will be converted to strings when you'll try to convert class object to plain object.

我使用 class-transformer 0.2.3 的示例代码没有按预期工作：

class TestDate {
  @Type(() => Date)
  aDate!: Date;
}

  const testDate = new TestDate();
  testDate.aDate = new Date();
  const result: any = classToPlain(testDate);
  console.log(typeof result.aDate);

这会将 object 打印到控制台，但我希望 string.
我错过了什么？

Answer 1

文档中的以下句子是错误的（参见class-transformer#326）：

Note, that dates will be converted to strings when you'll try to convert class object to plain object.

解决方法是使用@Transform:

  @Transform(value => (value as Date).toISOString(), {
    toPlainOnly: true
  })

Codesandbox example with workaround

Answer 2

为了扩展 TmTron 的答案，我需要创建两个转换器 - 每个方向一个。然后我使用 :

将它们组合成一个装饰器

// TransformDate.ts
import { Transform } from "class-transformer";

export default function TransformDate() {
  const toPlain = Transform((value) => (value as Date).toISOString(), {
    toPlainOnly: true,
  });

  const toClass = Transform((value) => new Date(value), {
    toClassOnly: true,
  });

  return function (target: any, key: string) {
    toPlain(target, key);
    toClass(target, key);
  };
}

用法：

// User.ts
import TransformDate from './TransformDate';

export default class User {
  id: string;
  @TransformDate()
  createdDate: Date;
  // ...
}

plainToClass 不会将日期转换为字符串

plainToClass does not convert a Date to string

typescript

class-transformer