Missing runtime_mappings support for async search requests

NEST/Elasticsearch.Net version: 7.14.1

Elasticsearch version: 7.14.1

.NET runtime version: 5.0

Description of the problem including expected versus actual behavior: Support for defining runtime mappings is missing from IAsyncSearchSubmitRequest and AsyncSearchSubmitDescriptor

When I did a diff between ISearchRequest and IAsyncSearchSubmitRequest I found that they were the same except ISearchRequest had these additional fields:

IRuntimeFields RuntimeFields
ISlicedScroll Slice
IPointInTime PointInTime
Fields Fields

I know async search doesn’t support snapshot and maybe some other things so not sure if any of these are missing on purpose, but generally it seems that async search is supposed to be pretty much the same as a regular search.

https://www.elastic.co/guide/en/elasticsearch/reference/current/async-search.html

[stevejgordon]

@ejsmith - The 7.15.0 release is now available https://github.com/elastic/elasticsearch-net/releases/tag/7.15.0

[stevejgordon]

Ahh I just noticed that I can get Total from HitsMetadata

Was just going to mention that, but we should have the shortcut property there as well. PointInTimeId would be needed too as it may represent a newer ID for the PIT if that was used on the search. Will get a PR in now.

Bit of a side discussion, but it sure would be nice if models like these shared some sort of interface in common since they are super similar.

I think there are historical reasons it’s been problematic to do so but I can see why it would be useful. I’ll flag that as something I can look at once code-gen is in place as that may dictate some of the design.