How to add DateOnly deserializer

[utillity]

Hi, I'm trying to add support for DateOnly - serialization works, but during deserialization I get an error (see below).

	private static IGremlinQueryEnvironment AddDateOnlySupport(this IGremlinQueryEnvironment environment) =>
		environment
			// serialization works
			.ConfigureSerializer(static serializer => serializer
				.ConfigureFragmentSerializer(static fragmentSerializer => fragmentSerializer
					.Override<DateOnly>(static (t, env, _, recurse) => recurse.Serialize(t.ToString("O"), env))))
			// deserialization doesn't
			.ConfigureDeserializer(static deserializer => deserializer
				.ConfigureFragmentDeserializer(static fragmentDeserializer => fragmentDeserializer
					.Override<JValue>(static (jValue, type, env, overridden, recurse) => type == typeof(DateOnly)
						? DateOnly.ParseExact(jValue.Value<string>(), "O")
						: overridden(jValue, type, env, recurse))))
		;

Error:

>> Newtonsoft.Json.JsonSerializationException
>> Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.DateOnly' because the type requires a JSON string value to deserialize correctly.
To fix this error either change the JSON to a JSON string value or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path '[0].id'. (CorrelationId=bf29a78b-224e-4cf1-9f3d-ed6cee133745)

[danielcweber]

Apparently jValue.Value<string>() throws, so: what is in jValue ?

[utillity]

my deserialization code is never invoked.

the Stack-Trace looks like this:

Newtonsoft.Json.JsonSerializationException
Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.DateOnly' because the type requires a JSON string value to deserialize correctly.
To fix this error either change the JSON to a JSON string value or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
Path '[0].id'.
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType)
   at Newtonsoft.Json.Linq.JToken.ToObject(Type objectType, JsonSerializer jsonSerializer)
   at ExRam.Gremlinq.Core.Deserialization.GremlinQueryFragmentDeserializer.<>c.<AddNewtonsoftJson>b__4_0(JToken jToken, Type type, IGremlinQueryEnvironment env, BaseGremlinQueryFragmentDeserializerDelegate`1 overridden, IGremlinQueryFragmentDeserializer recurse) in /_/src/ExRam.Gremlinq.Core/Deserialization/GremlinQueryFragmentDeserializer.cs:line 158
   at ExRam.Gremlinq.Core.Deserialization.GremlinQueryFragmentDeserializer.GremlinQueryFragmentDeserializerImpl.<>c__DisplayClass8_0`1.<Override>b__0(TSerialized fragment, Type type, IGremlinQueryEnvironment env, BaseGremlinQueryFragmentDeserializerDelegate`1 _, IGremlinQueryFragmentDeserializer recurse) in /_/src/ExRam.Gremlinq.Core/Deserialization/GremlinQueryFragmentDeserializer.cs:line 46
   at ExRam.Gremlinq.Core.Deserialization.GremlinQueryFragmentDeserializer.GremlinQueryFragmentDeserializerImpl.<>c__DisplayClass11_0`2.<CreateFunc1>b__0(TStatic serialized, Type fragmentType, IGremlinQueryEnvironment environment, IGremlinQueryFragmentDeserializer recurse) in /_/src/ExRam.Gremlinq.Core/Deserialization/GremlinQueryFragmentDeserializer.cs:line 94
....

[danielcweber]

Did you make sure AddDateOnlySupport is added as late as possible?

[utillity]

yes, it's the last thing in my .AddGremlinq(GremlinSetup). I find that my ConfigureFragmentDeserializer.Override is being invoked for all other objects which don't contain a DateOnly property.

[danielcweber]

You sure the data to be deserialized is really a raw Json value? Or that it is present at all?

[utillity]

the whole query is as follows:

g.inject(0).coalesce(
__.V(["19R","19R8GS2RO8V8R"]).hasLabel("CTC_Project"),__.V(["0HF","0HF85Q8KM72QA"]).addE("HasRight").property(id,"64A4R4AVEVF00").property("CreatedAt","2023-11-29T15:41:28.8663299+00:00").property("Right","Manage").to(__.coalesce(__.V(["19R","19R8GS2RO8V8R"]).hasLabel("CTC_Project"),
__.addV("CTC_Project").property(id,"19R8GS2RO8V8R").property(single,"CommercialStatus",0)
.property(single,"CommunicationScope",0).property(single,"CompactId","19R8GS2RO8V8R")
.property(single,"CreatedAt","2023-11-29T15:41:28.8663299+00:00").property(single,"CreeStatus",0)
.property(single,"DisplayName","Create-65J9EITIVREOM")
.property(single,"FullId","19R8GS2RO8V8R.19R.Project").property(list,"InternalTags","UnitTest")
.property(single,"IsDeleted",false).property(single,"PartitionKey","19R")
.property(single,"RegistrationDate","2023-11-29").property(single,"Status",1)
.property(single,"Timestamp",638368692888663119).property(single,"UnitOfMeasurement",0)
.property(single,"VertexType","Project")
.addE("CreatedBy").property(id,"5BJ358UI8H23K").property("CreatedAt","2023-11-29T15:41:28.8663299+00:00").to(__.V(["0HF","0HF85Q8KM72QA"])).outV())).inV())
.project("Item1","Item2")
.by(__.V(["0HF","0HF85Q8KM72QA"]).hasLabel("Company","SystemUser","User","Workspace").fold().coalesce(__.unfold(),__.constant("[[NULL]]")))
.by(__.V(["19R","19R8GS2RO8V8R"]).hasLabel("CTC_Project").fold().coalesce(__.unfold(),__.constant("[[NULL]]")))

RegistrationDate is being set to "2023-11-29"

The output from the query is as follows:

crit [Graph.Queries.ProjectRepository] Error deserializing result!
{
  "Item1": {
    "id": "F3781VIU1T0Q8",
    "label": "User",
    "type": "vertex",
    "properties": { ... }
  },
  "Item2": {
    "id": "AK1MUSD642ONO",
    "label": "CTC_Project",
    "type": "vertex",
    "properties": {
      "CommercialStatus": [
        {
          "id": "99e79949-eff0-48cb-aa2a-18fda6eb3cd9",
          "value": 0
        }
      ],
      "CommunicationScope": [
        {
          "id": "bee80cbc-ccda-4c72-a3df-f1c90b5743d0",
          "value": 0
        }
      ],
      "CompactId": [
        {
          "id": "07d0a50c-d62d-4919-a100-785df804b871",
          "value": "AK1MUSD642ONO"
        }
      ],
      "CreatedAt": [
        {
          "id": "a44d697d-1b84-4fa4-9116-b1b128e343d5",
          "value": 1701273036594
        }
      ],
      "CreeStatus": [
        {
          "id": "6054d70b-de65-4a29-a8ea-f6ac4b874527",
          "value": 0
        }
      ],
      "DisplayName": [
        {
          "id": "48568546-86a6-4101-aa04-4ce8cba5e8c8",
          "value": "Create-2V7BSR8SK9K0K"
        }
      ],
      "FullId": [
        {
          "id": "82791806-43e9-43a4-b88c-3919cd13e43c",
          "value": "AK1MUSD642ONO.AK1.Project"
        }
      ],
      "InternalTags": [
        {
          "id": "b72b5baf-9ce9-4d42-8689-aba0641c936c",
          "value": "UnitTest"
        }
      ],
      "IsDeleted": [
        {
          "id": "9314c0c3-3b10-42b3-88e2-d3a4de23f826",
          "value": false
        }
      ],
      "PartitionKey": [
        {
          "id": "AK1MUSD642ONO|PartitionKey",
          "value": "AK1"
        }
      ],
      "RegistrationDate": [
        {
          "id": "7326ded0-f6de-423e-952c-37a73ef52c15",
          "value": "2023-11-29"
        }
      ],
      "Status": [
        {
          "id": "c50f5767-1a81-432a-af2e-9b455dfe4d59",
          "value": 1
        }
      ],
      "Timestamp": [
        {
          "id": "80d4fa1a-e480-4035-bed0-53b303a05af4",
          "value": 638368698365946204
        }
      ],
      "UnitOfMeasurement": [
        {
          "id": "325e9cc6-d33e-4ae3-81dc-5f74fbac0bbe",
          "value": 0
        }
      ],
      "VertexType": [
        {
          "id": "6fc3fc9b-ba95-4015-a2fd-56e06c7ae5ae",
          "value": "Project"
        }
      ]
    }
  }
}

[danielcweber]

What does the deserialized class look like (code and actual instance)?

[utillity]

I created a test to illustrate the issue:

	private class TestVertex
	{
		public string Id { get; set; } = UnifiedId.NewId().ToString();
		public DateOnly? Date { get; set; }
		public string PartitionKey { get; set; } = "Test";
		public string[] ListOne { get; set; }
		public string SomeProp { get; set; }
		public string DisplayName { get; set; }
	}


	[Fact]
	public async Task AddDateOnlySupport()
	{
		var v = new TestVertex { SomeProp = "Test", Date = TimeProvider.Instance.Today };
		Output.WriteLine(v.ToJson(true));
		var q = graph.AddV(v);
		Output.WriteLine(q.DebugWithMerge());
		var result = await q.GetFirstOrDefault();
		Output.WriteLine(result.ToJson(true));
		result.Date.Should().Be(v.Date);
	}

Query:

g.addV("TestVertex").property(id,"CI2CM98V68B0M").property(single,"Date","2023-11-29")
.property(single,"DisplayName","Test").property(single,"PartitionKey","Test").property(single,"SomeProp","Test")

Returns:

{
  "id": "CI2CM98V68B0M",
  "label": "TestVertex",
  "type": "vertex",
  "properties": {
    "Date": [
      {
        "id": "caf62b01-70f9-4b1e-9ac5-d184b4505a87",
        "value": "2023-11-29"
      }
    ],
    "DisplayName": [
      {
        "id": "6a4e35ac-e973-4d47-b767-c749a239630b",
        "value": "Test"
      }
    ],
    "PartitionKey": [
      {
        "id": "CI2CM98V68B0M|PartitionKey",
        "value": "Test"
      }
    ],
    "SomeProp": [
      {
        "id": "f29243ee-3b81-404d-b613-da1bfee188f7",
        "value": "Test"
      }
    ]
  }
}

Error:

Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.DateOnly' because the type requires a JSON string value to deserialize correctly.

[danielcweber]

Try without nullability.

[utillity]

changed Date property to not-nullable, same error

[danielcweber]

So I have no ideas left, that's all I can offer by just looking at code snippets. If you got the time and the passion, upgrade to a preview of v12, (de)serialization things are very different there but much much better. I don't deal too much with v11 anymore these days, there is just no time. If you feel there is definitely a bug, please link to a working minimal repro project and if there is a bug, it will probably get fixed.

[utillity]

thanks for trying, Daniel, I will test out the v12 and let you know. I appreciate your help in any case. best, Tilli