Wrong contract for KafkaEx.create_topics

[VitorTrin]

The documentation says that it receives a KafkaEx.Protocol.CreateTopics.Request struct, except the only valid input is a list of KafkaEx.Protocol.CreateTopics.TopicRequest structs.

[joshuawscott]

Good catch, we'd welcome a PR to fix it.

[VitorTrin]

Should we enforce the usage of Request or simply change the documentation? Because as it is Request has no use and just sending a list is simpler. On the other hand, sending a Request an receiving a Response seems to be a design decision

[jbruggem]

I checked the code, and if I'm correct CreateTopics.Request is used internally to translate the request into Kafka's binary protocol. It's not meant to be used by users of KafkaEx.

So indeed, it's a question of changing the documentation.

What I don't understand is that the spec already looks correct, so I can't figure out what I'm missing.

In kafka_ex.ex:

# ...
# ...
# ...
alias KafkaEx.Protocol.CreateTopics.TopicRequest, as: CreateTopicsRequest
# ...
# ...
# ...
# ...
# ...
  @spec create_topics([CreateTopicsRequest.t()], Keyword.t()) ::
          CreateTopicsResponse.t()
  def create_topics(requests, opts \\ []) do
    worker_name = Keyword.get(opts, :worker_name, Config.default_worker())
    timeout = Keyword.get(opts, :timeout)
    Server.call(worker_name, {:create_topics, requests, timeout})
  end

[jbruggem]

The contract is correct if I generate the doc on my machine:

On hexdocs:

@joshuawscott any idea what would cause the difference ?

[joshuawscott]

@jbruggem looks like it's been fixed in master already at some point. I'm going to close this; we probably do need to cut a new release, though.