@count/@size not supported for mixed containing a collection

[nirinchev]

Looks like @count is not a supported operator when querying a mixed property, even if the value contains a collection. Am I misunderstanding how the query should be constructed or is this a scenario that will never work? Here's a simplified test in dart:

realm.write(() {
  realm.add(AnythingGoes(
    oneAny: RealmValue.from([
      1,
      'a',
      {'foo': 'bar'}
    ])));

});

final listLengthQuery = realm.query<AnythingGoes>('oneAny.@size > 2');

oneAny is a property of type Mixed; we're adding a list to it and then trying to find all objects where oneAny has size > 2. I would expect this to implicitly translate to something like oneAny.@type IN [List, Dictionary] && oneAny.asCollection().@size > 2.

[jedelbo]

Fixed by #7287