How do we deal with nil/null/undefined in maps?

[samedhi]

I think the rule should be that passing in nil always results in nil being written to the datastore. If you want to use the default value then don't include the key.

Or maybe it is the intersection of nil, default, and required? Should it automatically write the default in the event that it is also required and nil is passed in as a named value?

Thinking about it a bit more, I kind of feel that nil just shouldn't be allowed at all as a value to a property. nil should be indicated by the absence of a property, not by the fact that there is property that has been written with nil.