Include generic parameters in record name

[charlibot]

Fixes "Generic parameters are not included in a record name" of #442.

Follows the same conventions as Avro4s by separating the case class name and types with __ and the types themselves with _.

[bplommer]

I like this but I'd like to make it configurable so we don't make breaking changes to existing code - it would also be good to have configurable separators I think.

We could either add a version of derive that takes configuration arguments or add a new annotation AvroNameWithParamNames(name: String, sep1: String = "__", sep2: String = "_") - I lean to the first option, what do you think?

I'm also open to better naming suggestions 🙂

[charlibot]

Thanks for the feedback @bplommer - I also prefer the first option of passing configuration parameters to the derive method. Will try to get that working in the PR.

[bplommer]

One thing I'd say is to use a builder rather than a case class for the config so that it can be extended later in a binary compatible way. Not sure how familiar you are with that pattern, happy to go into more detail if needed.

[charlibot]

@bplommer - I have something working for Scala 2 and am a little stuck on Scala 3. Before getting in too deep, I wanted to check with you I'm heading in the right direction.

I've added a Configuration case class with withTypeSeparators as a sort of builder method; I was taking inspiration from circe-generic-extra's config class. Then this is wired in as an implicit parameter.

[erikvanoosten]

@bplommer Are you sure you want to make the separators configurable? What kind of use case do you have in mind? It seems to need a lot of code so we should be sure it is worth it.

[eugkhp]

Hey! @bplommer any update on this, is it possible to merge it? I'm also migrating from avro4s and this would be nice to have

[eugkhp]

I think I found the solution how to do it without modifying the libarary

  final case class Event[A: Codec](
      eventId: EventId,
      eventTimestamp: Instant,
      data: A,
    )

  object Event {
    implicit def codec[A: Codec]: Codec[Event[A]] =
      Codec.record[Event[A]](
        s"${Codec[A].schema.map(sc => s"Event__${sc.getName}").getOrElse("couldn't derive avro schema for A")}",
        s"${Codec[A].schema.map(_.getNamespace).getOrElse("couldn't derive avro schema for A")}",
      )(builder =>
        (
          builder("eventId", _.eventId),
          builder("eventTimestamp", _.eventTimestamp),
          builder("data", _.data),
        ).mapN(Event(_, _, _))
      )
  }

but this won't solve anything nested ofc 😔