Here is how you can implement chunk using TypeScript:

```ts
export function chunk<T>(items: readonly T[], size: number): T[][] {
  if (size < 1) throw new Error('Size must be a positive integer.');
    const result = [];
    for(let i =0; i < items.length; i += size){
        result.push(items.slice(i, i + size))
    }
  return result;
}
```