Refer: Easy - Parameters

Describe

Implement the built-in Parameters generic without using it.

Test Cases

code snippetCopytypescript
import { Equal, Expect, ExpectFalse, NotEqual } 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>, []>>,
]

Solution

code snippetCopytypescript
type MyParameters<T extends (...args: any[]) => any> = T extends (...args: infer P) => any ? P : never