```ts
export function chunk<T>(items: readonly T[], size: number): T[][] {
  if (!Number.isInteger(size) || size <= 0) {
    throw new Error("Size must be a positive integer");
  }
  return items.length === 0 ? [] : Array.from({ length: Math.ceil(items.length / size) }, (_, i) => items.slice(i * size, (i + 1) * size));
}
```