     {File.read!(file), file: file}
   end
 
-  defp write_file("-", contents), do: IO.write(contents)
+  defp write_file(:stdin, contents), do: IO.write(contents)
   defp write_file(file, contents), do: File.write!(file, contents)
 
   defp format_file(file, task_opts, formatter_opts) do

  end

  defp to_bullet_list(files) do
    Enum.map_join(files, "\n", &bullet_line/1)
  end

  defp bullet_line("-"), do: ["  * stdin"]

  defp bullet_line(file), do: ["  * ", file]

  defp equivalent?(input, output) do
    Code.Formatter.equivalent(input, output) == :ok

       end
  end

  defp stdin_or_wildcard("-"), do: [:stdin]
  defp stdin_or_wildcard(path), do: Path.wildcard(path)

  defp read_file(:stdin) do
    {IO.stream(:stdio, :line) |> Enum.to_list() |> IO.iodata_to_binary(), file: "stdin"}
  end

