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https://issues.apache.org/jira/browse/TINKERPOP-2581?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17364895#comment-17364895
]
Florian Hockmann commented on TINKERPOP-2581:
---------------------------------------------
This sounds to me like Cosmos DB didn't send a valid GraphSON 3 message as
[GraphSON 3
specifies|https://tinkerpop.apache.org/docs/current/dev/io/#_integer_2] that
numerical types should be serialized like an object. The Cosmos DB docs also
still [mention that they don't support GraphSON
3|https://docs.microsoft.com/en-us/azure/cosmos-db/gremlin-support#unsupported-features].
So, this is not a bug in Gremlin.NET but a known limitation of Cosmos DB.
> Gremlin.NET throwing an exception when having to deserialize Numbers in edges
> -----------------------------------------------------------------------------
>
> Key: TINKERPOP-2581
> URL: https://issues.apache.org/jira/browse/TINKERPOP-2581
> Project: TinkerPop
> Issue Type: Bug
> Components: dotnet
> Affects Versions: 3.5.0
> Environment: Azure CosmosDB graph
> Reporter: Fredy
> Priority: Major
>
> We use Gremlin.NET against a CosmosDB graph and have upgraded our projects
> from 3.4.10 to 3.5.0 which I understand changed serialization to use
> System.Text.Json.
> We discovered that many of our queries that ended up retrieving edges were
> failing with the following ArgumentOutOfRangeException exception:
> {code:java}
> JSON type not supported.Parameter name: ValueKindActual value was Number.
> {code}
>
> We determined this happens for queries retrieving edges that have Number type
> JSON properties, most likely because Number is not considered in the ToObject
> method:
> [https://github.com/apache/tinkerpop/blob/a7181e23421818948de3624743d79361524c0013/gremlin-dotnet/src/Gremlin.Net/Structure/IO/GraphSON/GraphSONReader.cs#L103]
>
> A workaround that seems to work is instantiate our Gremlin.NET client with a
> subclass of GraphSON2Reader that accounts for this, but for the time being
> we've decided to rollback the update instead.
>
> Here's some code that triggers the issue, at least when using the CosmosDB
> backend which is what we use:
> {code:java}
> using Gremlin.Net.Driver;
> using Gremlin.Net.Structure.IO.GraphSON;
> using System;
> using System.Text.Json;
> using System.Threading.Tasks;namespace GremlinNetTest
> {
> class Program
> {
> static async Task Main(string[] _)
> {
> var (hostname, port, username, password) = (
> "<redacted>",
> 443,
> "<redacted>",
> "<redacted>"
> );
> var server = new GremlinServer(hostname, port, enableSsl: true,
> username, password);
> var client = new GremlinClient(server, new
> GraphSON2MessageSerializer(new GraphSON2Reader(), new GraphSON2Writer()));
> // Create vertexes.
> var (v1Id, v2Id) = (Guid.NewGuid().ToString(),
> Guid.NewGuid().ToString());
> await
> client.SubmitAsync<dynamic>($"g.addV('item').property('id','{v1Id}').property('pk','0')");
> await
> client.SubmitAsync<dynamic>($"g.addV('item').property('id','{v2Id}').property('pk','0')");
> // Create edge with string property works.
> await
> client.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('works').to(g.V(['0','{v2Id}'])).property('hello','world')");
> // Create edge with number property fails to deserialize result.
> // ** FAILS **
> await
> client.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('fails').to(g.V(['0','{v2Id}'])).property('number',
> 1)");
> await
> client.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('fails').to(g.V(['0','{v2Id}'])).property('long',
> 3147483647)");
> await
> client.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('fails').to(g.V(['0','{v2Id}'])).property('decimal',
> 1.5)");
> // ** /FAILS ** // Create edge with number property
> works to deserialize result with custom reader.
> var clientWithCustomReader = new GremlinClient(server, new
> GraphSON2MessageSerializer(new CustomReader(), new GraphSON2Writer()));
> await
> clientWithCustomReader.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('works').to(g.V(['0','{v2Id}'])).property('number',
> 1)");
> await
> clientWithCustomReader.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('works').to(g.V(['0','{v2Id}'])).property('long',
> 3147483647)");
> await
> clientWithCustomReader.SubmitAsync<dynamic>($"g.V(['0','{v1Id}']).addE('works').to(g.V(['0','{v2Id}'])).property('decimal',
> 1.5)");
> }
> } public class CustomReader : GraphSON2Reader
> {
> public override dynamic ToObject(JsonElement graphSon)
> {
> if (graphSon.ValueKind == JsonValueKind.Number)
> {
> if (graphSon.TryGetInt32(out int intValue)) return intValue;
> if (graphSon.TryGetInt64(out long longValue)) return
> longValue;
> if (graphSon.TryGetDecimal(out decimal decimalValue)) return
> decimalValue;
> }
> return base.ToObject(graphSon);
> }
> }
> }
> {code}
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