"Value cannot be null" when passing null arguments to SignalR client-side proxy
c#, json.net, signalr, signalr-hub
Solution
Turns out this is a known bug in SignalR that has been fixed and will be included in the upcoming 2.2.1 release. See their ticket here.
Problem
Using SignalR (v2.0.2) I'm getting this exception: ``` Value cannot be null. Parameter name: o at Newtonsoft.Json.Utilities.ValidationUtils.ArgumentNotNull(Object value, String parameterName) at Newtonsoft.Json.Linq.JToken.FromObjectInternal(Object o, JsonSerializer jsonSerializer) at Newtonsoft.Json.Linq.JToken.FromObject(Object o, JsonSerializer jsonSerializer) at Microsoft.AspNet.SignalR.Client.Hubs.HubProxy.Invoke[T](String method, Object[] args) ``` I'm calling the HubProxy with reflection, and I am passing in some null arguments that are triggering this error (aka, some items in the `Object[] args` are null). However, passing null for an argument to a method is a perfectly legitimate thing to do. Is this a bug in SignalR in that it is trying to serialize null parameters or is it a bug in Json.NET (v6.0.1) in that it shouldn't attempt to serialize a null object?