Dialyzer warning on Elixlsx.write_to_memory/2

[nkezhaya]

The pattern {'ok', {__filename@1, _binary@1}} can never match the type {'error',_}

Using Elixir 1.7.3 and Elixlsx 0.4.0:

 defmodule Foo do
   require Elixlsx

   alias Elixlsx.Sheet
   alias Elixlsx.Workbook

   @spec generate_report() :: binary()
   def generate_report() do
     sheet =
       Sheet.with_name("OSHA")
       |> Sheet.set_cell("B1", "wat")

     filename = "filename.xlsx"

     {:ok, {_filename, binary}} =
       %Workbook{sheets: [sheet]}
       |> Elixlsx.write_to_memory(filename)

     binary
   end
 end

[unti1x]

Well, that means that something wrong in :zip.create/2. Try to figure it out by using pattern {:error, reason}

[nkezhaya]

What's odd is, if I replace the call to write_to_memory/1 with wci = ...; :zip.create the warning goes away.