fixing update bug with DateTimeOffsets (#373)

* fixing update bug with DateTimeOffsets

* slightly better orginization

Author: slorello89

src/Redis.OM/Modeling/JsonDiff.cs

@@ -1,4 +1,7 @@
-using System.Web;
+using System;
+using System.Linq;
+using System.Text.Json;
+using System.Web;
 using Newtonsoft.Json.Linq;
 
 namespace Redis.OM.Modeling
@@ -35,8 +38,25 @@ public string[] SerializeScriptArgs()
             {
                 JTokenType.String => new[] { _operation, _path, $"\"{HttpUtility.JavaScriptStringEncode(_value.ToString())}\"" },
                 JTokenType.Boolean => new[] { _operation, _path, _value.ToString().ToLower() },
+                JTokenType.Date => SerializeAsDateTime(),
                 _ => new[] { _operation, _path, _value.ToString() }
             };
         }
+
+        private string[] SerializeAsDateTime()
+        {
+            var jValue = (JValue)_value;
+            if (jValue.Value is DateTimeOffset)
+            {
+                return new[]
+                {
+                    _operation,
+                    _path,
+                    $"{JsonSerializer.Serialize(_value.Value<DateTimeOffset>())}",
+                };
+            }
+
+            return new[] { _operation, _path, $"{JsonSerializer.Serialize(_value.Value<DateTime>())}" };
+        }
     }
 }

src/Redis.OM/Modeling/RedisCollectionStateManager.cs

@@ -104,7 +104,7 @@ internal bool TryDetectDifferencesSingle(string key, object value, out IList<IOb
             if (DocumentAttribute.StorageType == StorageType.Json)
             {
                 var dataJson = JsonSerializer.Serialize(value, RedisSerializationSettings.JsonSerializerOptions);
-                var current = JsonConvert.DeserializeObject<JObject>(dataJson, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
+                var current = JsonConvert.DeserializeObject<JObject>(dataJson, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore, DateFormatHandling = DateFormatHandling.IsoDateFormat, DateParseHandling = DateParseHandling.DateTimeOffset, DateTimeZoneHandling = DateTimeZoneHandling.Utc });
                 var snapshot = (JToken)Snapshot[key];
                 var diff = FindDiff(current!, snapshot);
                 differences = BuildJsonDifference(diff, "$", snapshot);

test/Redis.OM.Unit.Tests/RediSearchTests/SearchFunctionalTests.cs

@@ -1113,5 +1113,25 @@ public void TestSelectOnEmbeddedDocuments()
             Assert.Equal("World",resNoNew.InnerInnerCascade.Tag);
             Assert.Equal(42,resNoNew.InnerInnerCascade.Num);
         }
+
+        [Fact]
+        public void SaveDateTimeOffset()
+        {
+            var obj = new ObjectWithDateTimeOffsetJson
+            {
+                Offset = DateTimeOffset.Now,
+                DateTime = DateTime.Now
+            };
+            var collection = new RedisCollection<ObjectWithDateTimeOffsetJson>(_connection);
+            collection.Insert(obj);
+
+            var intermediate = collection.First(x => x.Id == obj.Id);
+            intermediate.Offset = intermediate.Offset.AddMinutes(10);
+            intermediate.DateTime = intermediate.DateTime.AddHours(1);
+            collection.Update(intermediate);
+            var final = collection.First(x => x.Id == obj.Id);
+            Assert.Equal(intermediate.Offset,final.Offset);
+            Assert.Equal(intermediate.DateTime,final.DateTime);
+        }
     }
 }

test/Redis.OM.Unit.Tests/RedisSetupCollection.cs

@@ -29,6 +29,7 @@ public RedisSetup()
             Connection.CreateIndex(typeof(ComplexObjectWithCascadeAndJsonPath));
             Connection.CreateIndex(typeof(BasicJsonObjectTestSave));
             Connection.CreateIndex(typeof(SelectTestObject));
+            Connection.CreateIndex(typeof(ObjectWithDateTimeOffsetJson));
         }
 
         private IRedisConnection _connection = null;
@@ -66,6 +67,7 @@ public void Dispose()
             Connection.DropIndexAndAssociatedRecords(typeof(ComplexObjectWithCascadeAndJsonPath));
             Connection.DropIndexAndAssociatedRecords(typeof(BasicJsonObjectTestSave));
             Connection.DropIndexAndAssociatedRecords(typeof(SelectTestObject));
+            Connection.DropIndexAndAssociatedRecords(typeof(ObjectWithDateTimeOffsetJson));
         }
     }
 }

test/Redis.OM.Unit.Tests/Serialization/ObjectWithDateTimeOffset.cs

@@ -8,4 +8,15 @@ public class ObjectWithDateTimeOffset
     {
         public DateTimeOffset Offset { get; set; }
     }
+
+    [Document(StorageType = StorageType.Json)]
+    public class ObjectWithDateTimeOffsetJson
+    {
+        [Indexed]
+        [RedisIdField]
+        public string Id { get; set; }
+
+        public DateTimeOffset Offset { get; set; }
+        public DateTime DateTime { get; set; }
+    }
 }