[Typescript] 67. Medium - Chunk

Do you know lodash? Chunk is a very useful function in it, now let's implement it. Chunk<T, N> accepts two required type parameters, the T must be a tuple, and the N must be an integer >=1

 

type exp1 = Chunk<[1, 2, 3], 2> // expected to be [[1, 2], [3]]
type exp2 = Chunk<[1, 2, 3], 4> // expected to be [[1, 2, 3]]
type exp3 = Chunk<[1, 2, 3], 1> // expected to be [[1], [2], [3]]

 

/* _____________ Your Code Here _____________ */

type Chunk<T extends any[], U extends number, ACC extends any[]= []> = ACC['length'] extends U 
  ? [ACC, ...Chunk<T, U>]
  : T extends [infer F, ...infer RT]
    ? Chunk<RT, U, [...ACC, F]>
    : ACC['length'] extends 0 
      ? []
      : [ACC];

/* _____________ Test Cases _____________ */
import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<Chunk<[], 1>, []>>,
  Expect<Equal<Chunk<[1, 2, 3], 1>, [[1], [2], [3]]>>,
  Expect<Equal<Chunk<[1, 2, 3], 2>, [[1, 2], [3]]>>,
  Expect<Equal<Chunk<[1, 2, 3, 4], 2>, [[1, 2], [3, 4]]>>,
  Expect<Equal<Chunk<[1, 2, 3, 4], 5>, [[1, 2, 3, 4]]>>,
  Expect<Equal<Chunk<[1, true, 2, false], 2>, [[1, true], [2, false]]>>,
]