FlatTable's.Map on a nested event property generates null-conditional member access resulting in compilation error

[migajek]

Please consider the following event:

public record MyEvent(Guid Id, ExtCompKey ItemId);

where ExtCompKey is a struct: public record struct ExtCompKey(string Identifier, int Key);

now when I try to Map it in the flat table projection:

Project<MyEvent>(m =>
{
    m.Map(x => x.ItemId.Key);
});

the code generation throws

System.InvalidOperationException: Compilation failures!

CS0023: Operator '?' cannot be applied to operand of type 'ExtCompKey'
...
case Marten.Events.IEvent<(redacted).MyEvent> event_MyEvent112:
                    operations.QueueSqlCommand("select public.mt_upsert_test1_myevent(?, ?);", event_MyEvent112.StreamId,
event_MyEvent112.Data.ItemId?.Key);
                    break;

the only workaround I found so far is to enrich the event with a direct accessor (public int ItmKey => ItemId.Key;) and use it in the Map expression

[jeremydmiller]

@migajek Happy to take a PR for this one if you want to dive in. Might not be that bad.

[migajek]

will look into it :)