29. MyParameters

[astak16]

题目

题目链接：MyParameters

实现 MyParameters，获取函数的参数类型

import type { Equal, Expect } from "@type-challenges/utils";

const foo = (arg1: string, arg2: number): void => {};
const bar = (arg1: boolean, arg2: { a: "A" }): void => {};
const baz = (): void => {};

type cases = [
  Expect<Equal<MyParameters<typeof foo>, [string, number]>>,
  Expect<Equal<MyParameters<typeof bar>, [boolean, { a: "A" }]>>,
  Expect<Equal<MyParameters<typeof baz>, []>>
];

答案

方法一

type MyParameters<Fn> = Fn extends (...args: infer Args) => void ? Args : never;