Why does dialyzer show no warning here?

[kokolegorille]

I had similar question here…

Type and spec - Dialyzer not detecting error

defmodule Lima do @type unit_quantity_t :: 0..1000 @type unit_quantity_error :: {:error, String.t()} @type unit_quantity_success :: {:ok, unit_quantity_t()} @type unit_quantity_result :: unit_quantity_success() | unit_quantity_error() @spec create_unit_quantity_error(s) :: r when s: String.t, r: unit_quantity_error() defp create_unit_quantity_error(msg), do: {:error, msg} @spec create_unit_quantity_success(n) :: r when n: unit_quantity_t(), r: unit_quantity_success() defp c…

and got nice answers.

TLDR:
As long as one path is ok, there will be no warning.
You can define type like good_response, bad_response.

:: binary() | error_type