能不能把map一个类型的属性名转成数组类型？

Question

Given the following type

type A = {
    foo: string
    bar: number
}

is it possible to create a mapped/conditional type such that

type APropertyNameList = MapToProperyNameList<A>

let l1: APropertyNameList = ["foo", "bar] //correct
let l2: APropertyNameList = ["foo", "boom"] //compile error
let l3: APropertyNameList = ["foo", "bar", "bar"] //compile error 2x bar

Answer 1

type A = {
    foo: string
    bar: number
}

type MyKeys<T> = (keyof T)[];

const l1: MyKeys<A> = ['foo', 'bar'] // Correct
const l2: MyKeys<A> = ['foo', 'boom'] // Error