Kafka: authenticate with Event Hubs using OAuth2

[spenes]

#57

[istreeter]

I think this is completely fine.

My only comment is... previously when I've seen ClassTag used, it has always been passed implicitly. So something like:

  def resource[F[_]: Async, T <: AzureAuthenticationCallbackHandler: ClassTag](
    config: KafkaSinkConfig
  ): Resource[F, Sink[F]] = {

Then in your loader it would look like:

override def badSink: SinkProvider = KafkaSink.resource[F, SinkAuthHandler](_)

To be honest, I'm not 100% certain whether that is the convention to pass ClassTags implicitly. Maybe it's just the examples I've seen.

[spenes]

Thanks @istreeter! Actually, I tried that but realized that compiler doesn't enforce type parameter to be passed. So, it can be called like this still:

override def badSink: SinkProvider = KafkaSink.resource(_)

In that case, it gives following error while trying to initiate Kafka consumer/producer:

Could not instantiate class scala.runtime.Nothing

It works fine if type parameter is given. However, I think it is prone to obscure bugs since we don't get compiler error if type parameter isn't passed. Therefore, I decided to pass ClassTag explicitly instead.