Graphql "contains" does not perform case-insensitive regex. Having problems creating a custom handler using MongoDbStringOperationHandler.

[matheusscsantos]

Hello everyone. I'm currently working on implementing case-insensitive filtering.

Context:

I have the following query .Searching for apple returns just titles that contains apple, but I would like it to be case insensitive(APPLE,Apple,...) :

query {
  test(type: "fruit", where: { title: { contains: "apple" } }) {
    items {
      id
      title
    }
  }
}

My service performs an aggregation like this:

var tests = Aggregate()
        .Match(filter);

Current Implementation:

I followed this https://chillicream.com/docs/hotchocolate/v14/api-reference/extending-filtering and created a similar filter handler:

public class MongoDbStringInvariantOperationHandler : MongoDbStringOperationHandler
{
  public MongoDbStringInvariantOperationHandler(InputParser inputParser) : base(inputParser)
  {
  }
  
  protected override int Operation => DefaultFilterOperations.Contains;
  
  public override MongoDbFilterDefinition HandleOperation(
    MongoDbFilterVisitorContext context, 
    IFilterOperationField field,
    IValueNode value, 
    object? parsedValue)
  {
    if (parsedValue is string str)
    {
      var doc = new MongoDbFilterOperation(
        "$regex",
        new BsonRegularExpression($"/^{Regex.Escape(str)}$/i"));

      return new MongoDbFilterOperation(context.GetMongoFilterScope().GetPath(), doc);
    }

    throw new InvalidOperationException();
  }
}

Problem:

The documentation mentions adding a convention for IQueryable like the one below, but since I'm returning an IExecutable, I'm unsure how to set up the convention properly for MongoDB filtering. It feels like a provider extension is missing for that.

.AddConvention<IFilterConvention>(
        new FilterConventionExtension(
            x => x.AddProviderExtension(
                new QueryableFilterProviderExtension(
                    y => y.AddFieldHandler<QueryableStringInvariantEqualsHandler>()))));

Could you guys share some tips on how I can create a convention for IExecutable or how I can do a query with case-insensitive contains?