error

:!mix test test/website_pipeline_test.exs
test/website_pipeline_test.exs:1: warning: redefining module WebsitePipeline
test/website_pipeline_test.exs:2: warning: variable 'fun' is unused
** (CompileError) test/website_pipeline_test.exs:4: function 'fun'/1 undefined
    (stdlib) lists.erl:1336: :lists.foreach/2
    (stdlib) erl_eval.erl:657: :erl_eval.do_apply/6
    (stdlib) erl_eval.erl:121: :erl_eval.exprs/5
    (elixir) src/elixir.erl:156: :elixir.erl_eval/2
    (elixir) src/elixir.erl:149: :elixir.eval_forms/4
    (elixir) src/elixir.erl:156: :elixir.erl_eval/2


shell returned 1

website_pipeline_test.exs

defmodule WebsitePipeline do
  def map(sites, fun) do
    sites
    |> Enum.map(fn(url) -> Task.async(fn -> url |> get_body |> fun end) end)
    |> Enum.map(&Task.await/1)
  end

  def get_body(url) do
    IO.puts url
    HTTPotion.get(url).body
  end

  defmodule Util do
    def extract_title(html) do
      title_pattern = ~r"<title>([^<]*)</title>"
      Regex.run(title_pattern, html) |> Enum.at(1)
    end
  end
end

defmodule WebsitePipelineTest do
  use ExUnit.Case
  alias WebsitePipeline.Util

  test "Mapping a pipeline of websites" do
    sites = ["http://example.org/", "http://slashdot.org", "http://elixir-lang.org", "http://www.erlang.org"]
    expected_titles = ["Example Domain", "Slashdot: News for nerds, stuff that matters", "Elixir", "Erlang Programming Language"]
    assert expected_titles == WebsitePipeline.map(sites, &Util.extract_title/1)
  end
end