How to call Render method of FilterDefinition in Mongo 3.1.0 c# drivers?

Question

upgrading to mongo c# driver 3.1.0 this code doesn't compile anymore:

public static BsonDocument ToBsonDocument<T>(this FilterDefinition<T> filter)
{
  var serializerRegistry = BsonSerializer.SerializerRegistry;
  var documentSerializer = serializerRegistry.GetSerializer<T>();
  return filter.Render(documentSerializer, serializerRegistry);
}

in the last release Render accepts one argument of type RenderArgs

i tried this but get the error:

Argument 1: cannot convert from 'MongoDB.Bson.Serialization.IBsonSerializer' to 'string'

public static BsonDocument ToBsonDocument<T>(this FilterDefinition<T> filter)
{
  var serializerRegistry = BsonSerializer.SerializerRegistry;
  var documentSerializer = serializerRegistry.GetSerializer<T>();
  return filter.Render(new PathRenderArgs(documentSerializer, serializerRegistry));
}

Answer 1

The latest Render method in the FilterDefinition class is no longer supported with two arguments, but with the argument with RenderArgs<Document> type.

public abstract class FilterDefinition<TDocument>
{
    public abstract BsonDocument Render(RenderArgs<TDocument> args);

   ...
}

And from the constructor, you can provide both IBsonSerializer<TDocument> and IBsonSerializerRegistry instances.

public record struct RenderArgs<TDocument>
{

    public RenderArgs(
        IBsonSerializer<TDocument> documentSerializer,
        IBsonSerializerRegistry serializerRegistry,
        PathRenderArgs pathRenderArgs = default,
        bool renderDollarForm = default,
        bool renderForFind = false,
        bool renderForElemMatch = false,
        ExpressionTranslationOptions translationOptions = null)
    {
        ...
    }

   ...
}

Thus, modify the ToBsonDocument method as below:

public static BsonDocument ToBsonDocument<T>(this FilterDefinition<T> filter)
{
    var serializerRegistry = BsonSerializer.SerializerRegistry;
    var documentSerializer = serializerRegistry.GetSerializer<T>();
    return filter.Render(new RenderArgs<T>(documentSerializer, serializerRegistry));
}