Validation waffle

validate.ex

  def validate({file, _}) do
    {:ok, info} = File.stat(file.path)

    if info.size < 2_000_000 do
      file_extension = file.file_name |> Path.extname() |> String.downcase()

      case Enum.member?(~w(.jpg .jpeg .gif .png), file_extension) do
        true -> :ok
        false -> {:error, "file type is invalid"}
      end
    else
      {:error, "file size is too large"}
    end
  end