In porting existing .NET / Windows Phone code, I discovered a behavior of DataContractJsonSerializer in MonoTouch that is inconsistent with other platforms.
Specifically, when deserializing JSON where an array property has a null value, DataContractJsonSerializer incorrectly maps the null value to an empty array. This is problematic because it causes you to lose the ability to differentiate between null and empty.
For example, given the below class and JSON:
public class Response
public Notification Notifications
With MonoTouch, Notifications is set to Notification, whereas on other platforms, Notifications is correctly set to null.
Could you look at this one?
I confirmed it reproduces on Mono 4.0. It's fixed in Mono 4.2 because we moved to Reference Sources.
Curiously, while looking at it I was somewhat confused cause we still had a copy of DataContractJsonSerializer in System.ServiceModel.Web that's not used anymore. I opened https://github.com/mono/mono/pull/2185 to cleanup those and added the test from this bug while I was at it.