Test query issue in StoreControllerTest

[anpete]

Queries that used to return an entity with InMemory store now return null.

Repro Test: https://github.com/aspnet/MusicStore/blob/dc60a2e9c5e89d4f4324bb82e5c1af17f7d4490b/test/MusicStore.Test/StoreControllerTest.cs#L108

The query: https://github.com/aspnet/MusicStore/blob/dc60a2e9c5e89d4f4324bb82e5c1af17f7d4490b/samples/MusicStore/Controllers/StoreController.cs#L59-L63

album = await DbContext.Albums
               .Where(a => a.AlbumId == id)
               .Include(a => a.Artist)
               .Include(a => a.Genre)
               .FirstOrDefaultAsync();

When the .Include extensions are removed from the query, it returns an entity as expected.

Reason: Artist should never be null here - It is configured in the model as Required by convention because Album.ArtistId is not nullable. Either configure the relationship to be Optional, or ensure that the test albums have artists assigned.

[kichalla]

4039126e16fa13a464818d065aa4b381fb749e4f