```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 start = 0; start < items.length; start += size) {
        result.push(items.slice(start, start + size));
    }

    return result;
}
```