Swagger & Slate Integration consistently erroring

[hgg]

What I'm trying achieve

I'm trying to use the integration with Swagger & Slate to generate API docs automatically.
I've followed to the letter the guidelines.

What is happening

When I run DOC=1 mix test, all the tests pass but I get the following error:

11:09:17.606 [error] GenServer #PID<0.519.0> terminating
** (Protocol.UndefinedError) protocol Enumerable not implemented for nil of type Atom. This protocol is implemented for the following type(s): DBConnection.PrepareStream, DBConnection.Stream, Date.Range, Ecto.Adapters.SQL.Stream, File.Stream, Function, GenEvent.Stream, HashDict, HashSet, IO.Stream, Jason.OrderedObject, List, Map, MapSet, Phoenix.LiveView.LiveStream, Postgrex.Stream, Range, Stream
    (elixir 1.14.5) lib/enum.ex:1: Enumerable.impl_for!/1
    (elixir 1.14.5) lib/enum.ex:166: Enumerable.reduce/3
    (elixir 1.14.5) lib/enum.ex:1150: Enum.find/3
    (bureaucrat 0.2.9) lib/bureaucrat/swagger_slate_markdown_writer.ex:236: Bureaucrat.SwaggerSlateMarkdownWriter.write_operations_for_tag/4
    (elixir 1.14.5) lib/enum.ex:975: Enum."-each/2-lists^foreach/1-0-"/2
    (elixir 1.14.5) lib/enum.ex:1662: anonymous fn/3 in Enum.map/2
    (stdlib 5.0.2) maps.erl:416: :maps.fold_1/4
    (elixir 1.14.5) lib/enum.ex:2480: Enum.map/2
    (bureaucrat 0.2.9) lib/bureaucrat/formatter.ex:22: Bureaucrat.Formatter.suite_finished/0
    (stdlib 5.0.2) gen_server.erl:1103: :gen_server.try_handle_cast/3
    (stdlib 5.0.2) gen_server.erl:1165: :gen_server.handle_msg/6
    (stdlib 5.0.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3
Last message: {:"$gen_cast", {:suite_finished, %{async: 163093, run: 509077, load: nil}}}
11:09:17.612 [error] Task #PID<0.501.0> started from #PID<0.101.0> terminating
** (stop) exited in: GenServer.stop(#PID<0.519.0>, :normal, :infinity)
    ** (EXIT) exited in: :sys.terminate(#PID<0.519.0>, :normal, :infinity)
        ** (EXIT) an exception was raised:
            ** (Protocol.UndefinedError) protocol Enumerable not implemented for nil of type Atom. This protocol is implemented for the following type(s): DBConnection.PrepareStream, DBConnection.Stream, Date.Range, Ecto.Adapters.SQL.Stream, File.Stream, Function, GenEvent.Stream, HashDict, HashSet, IO.Stream, Jason.OrderedObject, List, Map, MapSet, Phoenix.LiveView.LiveStream, Postgrex.Stream, Range, Stream
                (elixir 1.14.5) lib/enum.ex:1: Enumerable.impl_for!/1
                (elixir 1.14.5) lib/enum.ex:166: Enumerable.reduce/3
                (elixir 1.14.5) lib/enum.ex:1150: Enum.find/3
                (bureaucrat 0.2.9) lib/bureaucrat/swagger_slate_markdown_writer.ex:236: Bureaucrat.SwaggerSlateMarkdownWriter.write_operations_for_tag/4
                (elixir 1.14.5) lib/enum.ex:975: Enum."-each/2-lists^foreach/1-0-"/2
                (elixir 1.14.5) lib/enum.ex:1662: anonymous fn/3 in Enum.map/2
                (stdlib 5.0.2) maps.erl:416: :maps.fold_1/4
                (elixir 1.14.5) lib/enum.ex:2480: Enum.map/2
                (bureaucrat 0.2.9) lib/bureaucrat/formatter.ex:22: Bureaucrat.Formatter.suite_finished/0
                (stdlib 5.0.2) gen_server.erl:1103: :gen_server.try_handle_cast/3
                (stdlib 5.0.2) gen_server.erl:1165: :gen_server.handle_msg/6
                (stdlib 5.0.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3
    (elixir 1.14.5) lib/gen_server.ex:995: GenServer.stop/3
    (ex_unit 1.14.5) lib/ex_unit/event_manager.ex:22: anonymous fn/2 in ExUnit.EventManager.stop/1
    (elixir 1.14.5) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
    (ex_unit 1.14.5) lib/ex_unit/event_manager.ex:21: ExUnit.EventManager.stop/1
    (ex_unit 1.14.5) lib/ex_unit/runner.ex:62: ExUnit.Runner.run_with_trap/2
    (ex_unit 1.14.5) lib/ex_unit/runner.ex:31: ExUnit.Runner.run/2
    (elixir 1.14.5) lib/task/supervised.ex:89: Task.Supervised.invoke_mfa/2
    (elixir 1.14.5) lib/task/supervised.ex:34: Task.Supervised.reply/4
    (stdlib 5.0.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3
Function: #Function<0.96829595/0 in ExUnit.async_run/0>
    Args: []
** (EXIT from #PID<0.101.0>) exited in: GenServer.stop(#PID<0.519.0>, :normal, :infinity)
    ** (EXIT) exited in: :sys.terminate(#PID<0.519.0>, :normal, :infinity)
        ** (EXIT) an exception was raised:
            ** (Protocol.UndefinedError) protocol Enumerable not implemented for nil of type Atom. This protocol is implemented for the following type(s): DBConnection.PrepareStream, DBConnection.Stream, Date.Range, Ecto.Adapters.SQL.Stream, File.Stream, Function, GenEvent.Stream, HashDict, HashSet, IO.Stream, Jason.OrderedObject, List, Map, MapSet, Phoenix.LiveView.LiveStream, Postgrex.Stream, Range, Stream
                (elixir 1.14.5) lib/enum.ex:1: Enumerable.impl_for!/1
                (elixir 1.14.5) lib/enum.ex:166: Enumerable.reduce/3
                (elixir 1.14.5) lib/enum.ex:1150: Enum.find/3
                (bureaucrat 0.2.9) lib/bureaucrat/swagger_slate_markdown_writer.ex:236: Bureaucrat.SwaggerSlateMarkdownWriter.write_operations_for_tag/4
                (elixir 1.14.5) lib/enum.ex:975: Enum."-each/2-lists^foreach/1-0-"/2
                (elixir 1.14.5) lib/enum.ex:1662: anonymous fn/3 in Enum.map/2
                (stdlib 5.0.2) maps.erl:416: :maps.fold_1/4
                (elixir 1.14.5) lib/enum.ex:2480: Enum.map/2
                (bureaucrat 0.2.9) lib/bureaucrat/formatter.ex:22: Bureaucrat.Formatter.suite_finished/0
                (stdlib 5.0.2) gen_server.erl:1103: :gen_server.try_handle_cast/3
                (stdlib 5.0.2) gen_server.erl:1165: :gen_server.handle_msg/6
                (stdlib 5.0.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3

What I've tried

• Adding the operation_id(...) to the operations in question.
  FYI this is missing from the guidelines. Let me know if you'd like me to add it.

---

Am I missing something? The swagger.json file seems to be being generated fine, but both the markdown and the HTML generated from it don't include any operations.

[hgg]

I got it working. I had to pass the operation_ids I'm using as elements on the tags field of the swagger_info object that is defined on the router. Shouldn't this be in the guidelines too?
example

  def swagger_info do
    %{
      info: %{
        version: "0.1",
        title: "Funky API"
      },
      basePath: "/api",
      tags: [
        %{name: "users", description: "Operations about Users"},
        # operation_ids
        %{name: "list_users", description: "List Users operation"},
        %{name: "invite_users", description: "Invite Users operation"}
      ]
    }
  end

EDIT: Just want to clearly state that I'm happy to provide a PR with these improvements 😁