Merge multiple documents to an array in ultra pipeline

That won’t be a problem here, because I’m using destructuring assignment ( the three dots ) before the $group array ...$group, this will always work for every $group array regardless of the array size, you don’t have to get each index from the $group array, just use ...$group, this will destructure the array and will be the same as writing $group[0]... $group[n] multiple times.