Error when elasticsearch url times out

[tfwright]

Hi, thanks for this useful library!

I'm trying to use a url for a remote elasticsearch instance, and for whatever reason, the connection appears to be timing out.

When I call Elasticsearch.get for that configuration

I expect: it to return a status tuple like {:error, "connection timed out"}

What happens: exception was raised

    ** (Protocol.UndefinedError) protocol Enumerable not implemented for %HTTPoison.Error{id: nil, reason: :connect_timeout} of type HTTPoison.Error (a struct). This protocol is implemented for the following type(s): Ecto.Adapters.SQL.Stream, Postgrex.Stream, DBConnection.Stream, DBConnection.PrepareStream, HashSet, Range, Map, Function, List, Stream, Date.Range, HashDict, GenEvent.Stream, MapSet, File.Stream, IO.Stream
        (elixir) lib/enum.ex:1: Enumerable.impl_for!/1
        (elixir) lib/enum.ex:141: Enumerable.reduce/3
        (elixir) lib/enum.ex:3023: Enum.reverse/1
        (elixir) lib/enum.ex:2668: Enum.to_list/1
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:351: Absinthe.Phase.Document.Execution.Resolution.split_error_value/1
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:341: Absinthe.Phase.Document.Execution.Resolution.put_result_error_value/5
        (elixir) lib/enum.ex:1948: Enum."-reduce/3-lists^foldl/2-0-"/3
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:256: Absinthe.Phase.Document.Execution.Resolution.build_result/4
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:153: Absinthe.Phase.Document.Execution.Resolution.do_resolve_fields/6
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:72: Absinthe.Phase.Document.Execution.Resolution.walk_result/5
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:53: Absinthe.Phase.Document.Execution.Resolution.perform_resolution/3
        (absinthe) lib/absinthe/phase/document/execution/resolution.ex:24: Absinthe.Phase.Document.Execution.Resolution.resolve_current/3
        (absinthe) lib/absinthe/pipeline.ex:274: Absinthe.Pipeline.run_phase/3
        (absinthe_plug) lib/absinthe/plug.ex:421: Absinthe.Plug.run_query/4
        (absinthe_plug) lib/absinthe/plug.ex:247: Absinthe.Plug.call/2
        (phoenix) lib/phoenix/router/route.ex:40: Phoenix.Router.Route.call/2
        (phoenix) lib/phoenix/router.ex:288: Phoenix.Router.__call__/2
        (ostraka) lib/ostraka_web/endpoint.ex:1: OstrakaWeb.Endpoint.plug_builder_call/2
        (ostraka) lib/ostraka_web/endpoint.ex:1: OstrakaWeb.Endpoint.call/2
        (phoenix) lib/phoenix/endpoint/cowboy2_handler.ex:42: Phoenix.Endpoint.Cowboy2Handler.init/4

"elasticsearch": {:hex, :elasticsearch, "1.0.0", "626d3fb8e7554d9c93eb18817ae2a3d22c2a4191cc903c4644b1334469b15374", [:mix], [{:httpoison, ">= 0.0.0", [hex: :httpoison, repo: "hexpm", optional: false]}, {:poison, ">= 0.0.0", [hex: :poison, repo: "hexpm", optional: true]}, {:sigaws, "~> 0.7", [hex: :sigaws, repo: "hexpm", optional: true]}, {:vex, "~> 0.6.0", [hex: :vex, repo: "hexpm", optional: false]}], "hexpm"},

[danielberkompas]

This is actually not due to the library raising an exception. It's due to Absinthe trying to treat the error value returned by the library as a list.