Optional (opt-in) DateTime.Kind serialization

.gitignore

@@ -2,4 +2,8 @@
 artifacts
 bin
 obj
-*.user
+*.user
+TestFiles/
+*.suo
+Tools/PEVerify.*
+packages/

Examples/Examples.csproj

@@ -229,6 +229,7 @@
     <Compile Include="Issues\Issue354.cs" />
     <Compile Include="Issues\Issue356.cs" />
     <Compile Include="Issues\Issue367.cs" />
+    <Compile Include="Issues\Issue44.cs" />
     <Compile Include="Issues\MissingBaseTypes.cs" />
     <Compile Include="Issues\SO11896228.cs" />
     <Compile Include="Issues\AssortedGoLiveRegressions.cs" />

Examples/Issues/Issue44.cs

@@ -0,0 +1,103 @@
+using NUnit.Framework;
+using ProtoBuf;
+using ProtoBuf.Meta;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Examples.Issues
+{
+    [TestFixture]
+    public class Issue44
+    {
+        [Test]
+        public void DateTimeKind_NotSerializedByDefault()
+        {
+            var model = TypeModel.Create();
+            model.AutoCompile = false;
+            Assert.AreEqual(false, model.IncludeDateTimeKind);
+        }
+
+        [Test]
+        public void  DateTimeKind_SerializedElectively_Enabled()
+        {
+            DateTimeKind_SerializedElectively(true, "DateTimeKind_SerializedElectively_Enabled");
+        }
+        [Test]
+        public void DateTimeKind_SerializedElectively_Disabled()
+        {
+            DateTimeKind_SerializedElectively(false, "DateTimeKind_SerializedElectively_Disabled");
+        }
+
+        private static void DateTimeKind_SerializedElectively(bool includeDateTimeKind, string name)
+        {
+            var model = TypeModel.Create();
+            model.AutoCompile = false;
+            model.IncludeDateTimeKind = includeDateTimeKind;
+            var original = HazTime.Create();
+
+            var clone = (HazTime)model.DeepClone(original);
+            CompareDates(original, clone, includeDateTimeKind, "runtime");
+
+            model.CompileInPlace();
+            clone = (HazTime)model.DeepClone(original);
+            CompareDates(original, clone, includeDateTimeKind, "CompileInPlace");
+
+            TypeModel compiled = model.Compile();
+            Assert.AreEqual(includeDateTimeKind, SerializeDateTimeKind(compiled));
+
+            clone = (HazTime)compiled.DeepClone(original);
+            CompareDates(original, clone, includeDateTimeKind, "Compile");
+
+            compiled = model.Compile(name, name + ".dll");
+            Assert.AreEqual(includeDateTimeKind, SerializeDateTimeKind(compiled));
+            clone = (HazTime)compiled.DeepClone(original);
+            CompareDates(original, clone, includeDateTimeKind, "Compile-dll");
+            PEVerify.AssertValid(name + ".dll");
+        }
+        static bool SerializeDateTimeKind(TypeModel model)
+        {
+            return (bool)typeof(TypeModel).GetMethod(
+                "SerializeDateTimeKind", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic).Invoke(model, null);
+        }
+
+        static void CompareDates(HazTime expected, HazTime actual, bool withKind, string model)
+        {
+            CompareDates(expected.Utc, actual.Utc, withKind ? DateTimeKind.Utc : DateTimeKind.Unspecified, model + ":Utc");
+            CompareDates(expected.Local, actual.Local, withKind ? DateTimeKind.Local : DateTimeKind.Unspecified, model + ":Local");
+            CompareDates(expected.Unspecified, actual.Unspecified, DateTimeKind.Unspecified, model + ":Unspecified");
+        }
+
+        static void CompareDates(DateTime expected, DateTime actual, DateTimeKind expectedKind, string caption)
+        {
+            Assert.AreEqual(expectedKind, actual.Kind, caption);
+            Assert.AreEqual(expected.Date, actual.Date, caption);
+            Assert.AreEqual(expected.TimeOfDay, actual.TimeOfDay, caption);
+        }
+
+        [ProtoContract]
+        public class HazTime
+        {
+            public static HazTime  Create()
+            {
+                var now = DateTime.UtcNow;
+                return new HazTime
+                {
+                    Utc = new DateTime(now.Ticks, DateTimeKind.Utc),
+                    Local = new DateTime(now.Ticks, DateTimeKind.Local),
+                    Unspecified = new DateTime(now.Ticks, DateTimeKind.Unspecified),
+                };
+            }
+            [ProtoMember(1)]
+            public DateTime Utc { get; set; }
+
+            [ProtoMember(2)]
+            public DateTime Local { get; set; }
+
+            [ProtoMember(3)]
+            public DateTime Unspecified { get; set; }
+        }
+    }
+}