Elixir test case with variable warning

idempotent_insert.exs

  test "inserting movies is idempotent" do
    movie_map = %{"title" => "The Goonies",
     "short_title" => "goonies",
     "year" => 1985,
     "country" => "U.S."}

    movie = Store.insert_movie(movie_map)

    movie_list = Eiga.Movie |> select([movie], movie.title) |> Eiga.Repo.all
    assert Enum.find(movie_list, &(&1 == movie_map["title"]))

    movie = Store.insert_movie(movie_map)
    assert Enum.filter(movie_list, &(&1 == movie_map["title"])) == [Enum.find(movie_list, &(&1 == movie_map["title"]))]

    Eiga.Repo.delete(movie)
  end