```ts
export function chunk<T>(items: readonly T[], size: number): T[][] {
  if (size <= 0 || !Number.isInteger(size)) {
    throw new Error('Size must be a positive integer');
  }

  const result: T[][] = [];
  for (let i = 0; i < items.length; i += size) {
    const chunk = items.slice(i, Math.min(items.length, i + size));
    result.push(chunk);
  }

  return result;
}
```