JsonSerializer/JsvTypeSerializer inconsistently uses the AssumeUtc config setting (#505)

DateTime handling is inconsistent with respect to the AssumcUtc when using the JSConfig setting.

If serializing to JSON - The JsonTypeSerializer will use the UTC specification type and convert Unspecified DateTime values to UTC in method "WriteWcfJsonDate"

If serializing to CSV- The JsvTypeSerializer will not use the UTC specification type and does not convert Unspecified DateTime values to UTC in method "ToShortestXsdDateTimeString"

Adding an internal extension method "UseConfigSpecifiedSetting" to match DateTime conversion between the two different serializers.

Author: Siliconrob

src/ServiceStack.Text/Common/DateTimeSerializer.cs

@@ -442,6 +442,7 @@ public static TimeSpan ParseXsdTimeSpan(string dateTimeStr)
 
         public static string ToShortestXsdDateTimeString(DateTime dateTime)
         {
+            dateTime = dateTime.UseConfigSpecifiedSetting();
             var timeOfDay = dateTime.TimeOfDay;
 
             var isStartOfDay = timeOfDay.Ticks == 0;
@@ -582,13 +583,18 @@ public static TimeZoneInfo GetLocalTimeZoneInfo()
 
         internal static TimeZoneInfo LocalTimeZone = GetLocalTimeZoneInfo();
 
-        public static void WriteWcfJsonDate(TextWriter writer, DateTime dateTime)
+        private static DateTime UseConfigSpecifiedSetting(this DateTime dateTime)
         {
             if (JsConfig.AssumeUtc && dateTime.Kind == DateTimeKind.Unspecified)
             {
-                dateTime = DateTime.SpecifyKind(dateTime, DateTimeKind.Utc);
+                return DateTime.SpecifyKind(dateTime, DateTimeKind.Utc);
             }
+            return dateTime;
+        }
 
+        public static void WriteWcfJsonDate(TextWriter writer, DateTime dateTime)
+        {
+            dateTime = dateTime.UseConfigSpecifiedSetting();
             switch (JsConfig.DateHandler)
             {
                 case DateHandler.ISO8601:

tests/ServiceStack.Text.Tests/JsonTests/JsonDateTimeTests.cs

@@ -2,6 +2,7 @@
 using System.Linq;
 using NUnit.Framework;
 using ServiceStack.Text.Common;
+using ServiceStack.Text.Jsv;
 
 namespace ServiceStack.Text.Tests.JsonTests
 {
@@ -309,6 +310,27 @@ public void When_using_ISO8601_and_serializing_as_Utc_It_should_deserialize_as_U
             Assert.AreEqual(initialDate, deserializedDate);
         }
 
+        [Test]
+        public void ISO8601_assumeUtc_serialize_datetime_is_the_same()
+        {
+            JsConfig.AssumeUtc = true;
+            JsConfig.DateHandler = DateHandler.ISO8601;
+            var initialDate = new DateTime(2012, 7, 25, 16, 17, 00, DateTimeKind.Unspecified);
+            var writers = new
+            {
+                jsv = new System.IO.StringWriter(new System.Text.StringBuilder()),
+                json = new System.IO.StringWriter(new System.Text.StringBuilder())
+            };
+            new JsvTypeSerializer().WriteDateTime(writers.jsv, initialDate);
+            new Json.JsonTypeSerializer().WriteDateTime(writers.json, initialDate);
+            var results = new
+            {
+                jsv = DateTime.SpecifyKind(DateTime.Parse(writers.jsv.ToString()), DateTimeKind.Utc),
+                json = DateTime.SpecifyKind(DateTime.Parse(writers.json.ToString().Replace("\"", "")), DateTimeKind.Utc)
+            };
+            Assert.AreEqual(results.jsv, results.json);
+        }
+
         [Test]
         public void Can_serialize_json_date_iso8601_utc()
         {