[Typescript] 12. Easy - Push

 

Implement the generic version of Array.push

For example:

type Result = Push<[1, 2], '3'> // [1, 2, '3']

 

/* _____________ Your Code Here _____________ */

type Push<T extends any[], U> = [
  ...T,
  U
]

type Equal<T, U> = 
  (<P>(x: P) => P extends T ? 1: 2) extends 
  (<P>(x: P) => P extends U ? 1: 2) 
    ? true
    : false
/* _____________ Test Cases _____________ */
import type { Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<Push<[], 1>, [1]>>,
  Expect<Equal<Push<[1, 2], '3'>, [1, 2, '3']>>,
  Expect<Equal<Push<['1', 2, '3'], boolean>, ['1', 2, '3', boolean]>>,
]