```ts

export function chunk<T>(items: readonly T[], size: number): T[][] {

    if (typeof size !== 'number' || size <= 0) {
        throw new Error('size must be a positive integer');
    }

    const result: T[][] = [];
    let index = 0;

    while (index < items.length) {
        const endIndex = Math.min(index + size, items.length);
        result.push(items.slice(index, endIndex));
        index = endIndex;
    }

    return result;
}
```