javascript - 一种在 TypeScript 中清理类构造函数的方法？

Question

目前我正在按以下方式定义我的类构造函数

class MyClass {

  routerStore: RouterStore
  characterStore: CharacterStore
  characterPrivateStore: CharacterPrivateStore

  constructor(
    routerStore: RouterStore,
    characterStore: CharacterStore,
    characterPrivateStore: CharacterPrivateStore
  ) {
    super()
    this.routerStore = routerStore
    this.characterStore = characterStore
    this.characterPrivateStore = characterPrivateStore
  }
}

这让我觉得冗长和重复。鉴于 TypeScript 利用了一些最新的 JavaScript 提案，我想问问是否有可能以某种方式清理它？

Answer 1

您可以向构造函数参数添加访问修饰符。这将使参数也是一个类字段，将使用参数的值进行初始化。

class MyClass {


   constructor(
       public routerStore: RouterStore,
       public characterStore: CharacterStore,
       public characterPrivateStore: CharacterPrivateStore
    ) {
       super()
   }
}

您还可以使用 Object.assign 在类上声明字段并使用映射类型仅提取字段键(不包括方法):

type JustFieldKeys<T> = { [P in keyof T] : T[P] extends Function ? never : P }[keyof T] 
class MyClass {

    public routerStore!: RouterStore,
    public characterStore!: CharacterStore,
    public characterPrivateStore!: CharacterPrivateStore
    constructor(params: Pick<MyClass, JustFieldKeys<MyClass>>) {
        Object.assign(this, params);
    }
}
new MyClass({
    characterPrivateStore: null,
    characterStore: null,
    routerStore: null
})