When no search results are returned, the aggregations are also missing

[shochdoerfer]

While developing the adapter for Sylius, I ran into an issue: When using the aggregations/filters and setting them to a combination that does not return results from Gally, the aggregations are missing in the response, and thus, the list of filters for the storefront cannot be built again. That leaves the customer with an empty search result list and no way to recover.

Obviously, it makes sense why this happens, but it is problematic for the user. The only "solution" to fix this that came to my mind would be to run the Elasticsearch query again but without the filters, build the aggregations as normal, and return them with the empty response. Or am I missing something?