[Typescript] 14. Easy - Parameters

Implement the built-in Parameters generic without using it.

For example:

const foo = (arg1: string, arg2: number): void => {}

type FunctionParamsType = MyParameters<typeof foo> // [arg1: string, arg2: number]

 

/* _____________ Your Code Here _____________ */

type MyParameters<T extends (...args: any[]) => any> = T extends (...args: infer Args) => any ? Args: never;


/* _____________ Test Cases _____________ */
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>, []>>,
]

 

posted @ 2022-09-03 23:44  Zhentiw  阅读(19)  评论(0编辑  收藏  举报