打字稿推断直接推断值并删除密钥是否有可能

Question

class A {
  state: B
}
class B {
  something: C
}
class C {
  a: string;
  b: boolean;
}

type MagicType = ...

const c: MagicType<A>

c.state.a = "123"
c.state.b = true;

如示例所述，在不更改 class 结构的情况下，是否可以使用魔术类型来实现此目的？

忽略 something 键，只导出 class c 属性

谢谢！

Answer 1

有对应的映射类型。

class Foo{
  constructor(public bar:string,public baz:number){}
}



type State<T> = {
  "state": { [P in keyof T]: T[P] };
};

var fooState: State<Foo> = {
  state : new Foo("bar",1)
}

console.log(fooState.state.bar);

游乐场link

另见 mapped types

打字稿推断直接推断值并删除密钥是否有可能

Is that possible that typescript inference to direct inference value and drop the key

types

inference

class

typescript