Resolve object empty string issue when using JS.Configure()

Author: mythz

src/ServiceStack.Text/Common/DeserializeType.cs

@@ -94,7 +94,9 @@ public static object ObjectStringToType(ReadOnlySpan<char> strType)
                 return primitiveType;
 
             if (Serializer.ObjectDeserializer != null && typeof(TSerializer) == typeof(Json.JsonTypeSerializer))
-                return Serializer.ObjectDeserializer(strType);
+                return !strType.IsNullOrEmpty()
+                    ? Serializer.ObjectDeserializer(strType)
+                    : strType.Value();
 
             return Serializer.UnescapeString(strType).Value();
         }

src/ServiceStack.Text/Json/JsonUtils.cs

@@ -42,7 +42,7 @@ public static class JsonUtils
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool IsWhiteSpace(char c)
         {
-            return c == ' ' || (c >= '\x0009' && c <= '\x000d') || c == '\x00a0' || c == '\x0085';
+            return c == ' ' || (c >= '\x0009' && c <= '\x000d') || c == '\x00a0' || c == '\x0085' || c == TypeConstants.NonWidthWhiteSpace;
         }
 
         public static void WriteString(TextWriter writer, string value)

tests/ServiceStack.Text.Tests/Issues/WhitespaceIssues.cs

@@ -1,4 +1,7 @@
-using NUnit.Framework;
+using System.IO;
+using Northwind.Common.DataModel;
+using NUnit.Framework;
+using ServiceStack.Text.Json;
 
 namespace ServiceStack.Text.Tests.Issues
 {
@@ -20,5 +23,27 @@ public void Does_deserialize_empty_string_to_object()
             var obj = json.FromJson<object>();
             Assert.That(obj, Is.EqualTo(""));
         }
+
+        public class ObjectEmptyStringTest
+        {
+            public object Name { get; set; }
+        }
+
+        [Test]
+        public void Does_serialize_property_Empty_String()
+        {
+            JS.Configure();
+            var dto = new ObjectEmptyStringTest { Name = "" };
+            var json = dto.ToJson();
+
+            var fromJson = json.FromJson<ObjectEmptyStringTest>();
+            Assert.That(fromJson.Name, Is.EqualTo(dto.Name));
+            
+            var utf8 = json.ToUtf8Bytes();
+            var ms = new MemoryStream(utf8);
+            var fromMs = JsonSerializer.DeserializeFromStream<ObjectEmptyStringTest>(ms);
+            Assert.That(fromMs.Name, Is.EqualTo(dto.Name));
+            JS.UnConfigure();
+        }
     }
 }