feat(serialization): Added support for writing nulls

Author: TwoTenPvP

MLAPI/Data/TypeExtensions.cs

@@ -14,5 +14,19 @@ internal static bool HasInterface(this Type type, Type interfaceType)
             }
             return false;
         }
+        
+        internal static bool IsNullable<T>(this T obj)
+        {
+            if (obj == null) return true;
+            
+            return typeof(T).IsNullable();
+        }
+
+        internal static bool IsNullable(this Type type)
+        {
+            if (!type.IsValueType) return true; // ref-type
+            if (Nullable.GetUnderlyingType(type) != null) return true; // Nullable<T>
+            return false; // value-type
+        }
     }
 }

MLAPI/NetworkingManagerComponents/Binary/BitReader.cs

@@ -89,6 +89,16 @@ public void SkipPadBits()
         /// <returns>Returns the boxed read object</returns>
         public object ReadObjectPacked(Type type)
         {
+            if (type.IsNullable())
+            {
+                bool isNull = ReadBool();
+
+                if (isNull)
+                {
+                    return null;
+                }
+            }
+            
             if (type == typeof(byte))
                 return ReadByteDirect();
             if (type == typeof(sbyte))

MLAPI/NetworkingManagerComponents/Binary/BitWriter.cs

@@ -6,6 +6,7 @@
 using System;
 using System.Diagnostics;
 using System.IO;
+using MLAPI.Internal;
 using UnityEngine;
 
 namespace MLAPI.Serialization
@@ -45,11 +46,17 @@ public void SetStream(Stream stream)
         /// <param name="value">The object to write</param>
         public void WriteObjectPacked(object value)
         {
-            if (value == null)
+            if (value.IsNullable())
             {
-                throw new NullReferenceException("BitWriter cannot write null values");
+                WriteBool(value == null);
+
+                if (value == null)
+                {
+                    return;
+                }
             }
-            else if (value is byte)
+            
+            if (value is byte)
             {
                 WriteByte((byte)value);
                 return;