```ts
export function chunk<T>(items: readonly T[], size: number): T[][] {
  /**
   * Splits an array into consecutive groups of at most `size` elements,
   * preserving order; the final group is shorter when the length does not divide evenly.
   *
   * @param items The input array to be split.
   * @param size The maximum size of each chunk.
   */
  if (typeof size !== 'number' || size <= 0) {
    throw new Error('size must be a positive integer');
  }

  const result: T[][] = [];

  for (let i = 0; i < items.length; i += size) {
    result.push(items.slice(i, i + size));
  }

  return result;
}
```