Linq provider uses Newtonsoft.Json configuration for property naming even when a custom CosmosSerializer is provided

[mumby0168]

We are continuously addressing and improving the SDK, if possible, make sure the problem persist in the latest SDK version.

Describe the bug

I have followed the sample from the samples repository to setup a System.Text.Json CosmosSerializer and configured the provided options to use CamelCase as the naming policy.

When I make a query to via the CosmosClient using the Linq provider the outputted query PascalCases the property queried.

For example if I wrote a document such as below:

{
    "firstName": "Haleigh",
    "lastName": "Yundt",
    "storeNumber": "q6",
    "joinedAtUtc": "2023-05-15T15:57:15.5556472+01:00",
    "id": "669252",
    "type": null,
    "_etag": "\"2e00d246-0000-0d00-0000-65c7abab0000\"",
    "_rid": "h8JCAIkmLzoFAAAAAAAAAA==",
    "_self": "dbs/h8JCAA==/colls/h8JCAIkmLzo=/docs/h8JCAIkmLzoFAAAAAAAAAA==/",
    "_attachments": "attachments/",
    "_ts": 1707584427
}

I then used the cosmos client to make a query as below:

IQueryable<TItem> query = container
            .GetItemLinqQueryable<TItem>()
            .Where(e => e.StoreNumber = "q6");

Then the ouputted query would be `select * from c where c.StoreNumber = 'q6`` unless I set the JsonPropertyAttribute on the class.

To Reproduce

1. Copy the SystemTextJsonCosmosSerializer from the samples.
2. Configure the serializer against the cosmos client and set the property naming policy to camel case
3. Define an object to use with at least two properties
4. Write this to a container
5. Query this back using the linq queryable option
6. See no results are returned

Expected behavior

It should either have a way to change this, or some configuration to pass to the client for the linq provider to support different naming.

Actual behavior

Queries the database with the incorrect casing returning no results.

Environment summary
SDK Version: <PackageVersion Include="Microsoft.Azure.Cosmos" Version="3.36.0" />
OS Version (e.g. Windows, Linux, MacOSX)

Additional context

There is a workaround which is to set the [JsonProperty("storeNumber")] on the class used, however, this feels a strange quirk when the library has been setup to use System.Text.Json.

[kirankumarkolli]

There are two serializers

Type	Stage	Scenarios	Description
CosmosSerializer	GA	All except LINQ	Only for POCO type serialization and se-serialization
Preview: CosmosLinqSerializer	Preview	All including LINQ	Hints to LINIQ about property name conversion

@mumby0168 Can you please test with the CosmosLinqSerializer which is currently in preview?

[Maya-Painter]

Adding a note here that if you want to apply camel casing using the CosmosLinqSerializer, SerializeMemberName() will need to be updated accordingly, e.g. something like

    class SystemTextJsonLinqSerializer : CosmosLinqSerializer
    {
        private readonly JsonObjectSerializer systemTextJsonSerializer;

        public SystemTextJsonLinqSerializer()
        {
            JsonSerializerOptions options = new()
            {
                PropertyNamingPolicy = JsonNamingPolicy.CamelCase
            };
            this.systemTextJsonSerializer = new JsonObjectSerializer(options);
        }

        public override T FromStream<T>(Stream stream)
        {
            if (stream == null)
                throw new ArgumentNullException(nameof(stream));

            using (stream)
            {
                if (stream.CanSeek && stream.Length == 0)
                {
                    return default;
                }

                if (typeof(Stream).IsAssignableFrom(typeof(T)))
                {
                    return (T)(object)stream;
                }

                return (T)this.systemTextJsonSerializer.Deserialize(stream, typeof(T), default);
            }
        }

        public override Stream ToStream<T>(T input)
        {
            MemoryStream streamPayload = new MemoryStream();
            this.systemTextJsonSerializer.Serialize(streamPayload, input, input.GetType(), default);
            streamPayload.Position = 0;
            return streamPayload;
        }

        public override string SerializeMemberName(MemberInfo memberInfo)
        {
            System.Text.Json.Serialization.JsonExtensionDataAttribute jsonExtensionDataAttribute =
                memberInfo.GetCustomAttribute<System.Text.Json.Serialization.JsonExtensionDataAttribute>(true);
            if (jsonExtensionDataAttribute != null)
            {
                return null;
            }

            JsonPropertyNameAttribute jsonPropertyNameAttribute = memberInfo.GetCustomAttribute<JsonPropertyNameAttribute>(true);
            if (!string.IsNullOrEmpty(jsonPropertyNameAttribute?.Name))
            {
                return jsonPropertyNameAttribute.Name;
            }

            return System.Text.Json.JsonNamingPolicy.CamelCase.ConvertName(memberInfo.Name);
        }
    }

[Maya-Painter]

@mumby0168 Just following up, did using the provided CosmosLinqSerializer address your concerns?

[JarFrank]

@Maya-Painter
It works for me, but the question is: will you release CosmosLinqSerializer class in the next version? I don't want to use preview in production.

[Maya-Painter]

@JarFrank thanks for checking. Yes, unless any valid concerns are brought up about the feature by users, we will include it as part of the next public release and update documentation accordingly.

[Maya-Painter]

Closing this issue as addressed. This feature will also be released in the next public version - #4323