Array with least number of elements

arr.ts

type AtLeast<N extends number, T> = AtLeastRec<N, T, T[], []>;

type AtLeastRec<Num, Elm, T extends unknown[], C extends unknown[]> = {
  0: T;
  1: ((arg: Elm, ...rest: T) => void) extends ((...args: infer T2) => void)
    ? ((arg: unknown, ...rest: C) => void) extends ((...args: infer T3) => void)
      ? AtLeastRec<Num, Elm, T2, T3>
      : never
    : never;
}[C extends { length: Num } ? 0 : 1];

const arr: AtLeast<3, number> = [0, 1];
const arr2: AtLeast<3, number> = [0, 1, 2];