fix(export): order member export chronologically by custom :date fields

lib/mv_web/controllers/member_export_controller.ex

@@ -12,6 +12,7 @@ defmodule MvWeb.MemberExportController do
 
   alias Mv.Authorization.Actor
   alias Mv.Membership.CustomField
+  alias Mv.Membership.CustomFieldSort
   alias Mv.Membership.Member
   alias Mv.Membership.MemberExport
   alias Mv.Membership.MembersCSV
@@ -523,18 +524,22 @@ defmodule MvWeb.MemberExportController do
         false
 
       cfv ->
-        extracted = extract_sort_value(cfv.value, custom_field.value_type)
+        not empty_custom_field_value?(cfv.value, custom_field.value_type)
-        not empty_value?(extracted, custom_field.value_type)
     end
   end
 
-  defp empty_value?(nil, _type), do: true
+  defp empty_custom_field_value?(%Ash.Union{value: value, type: type}, _expected_type) do
+    empty_custom_field_value?(value, type)
+  end
 
-  defp empty_value?(value, type) when type in [:string, :email] and is_binary(value) do
+  defp empty_custom_field_value?(nil, _type), do: true
+
+  defp empty_custom_field_value?(value, type)
+       when type in [:string, :email] and is_binary(value) do
     String.trim(value) == ""
   end
 
-  defp empty_value?(_value, _type), do: false
+  defp empty_custom_field_value?(_value, _type), do: false
 
   defp find_cfv(member, custom_field) do
     (member.custom_field_values || [])
@@ -548,7 +553,7 @@ defmodule MvWeb.MemberExportController do
   defp extract_member_sort_value(member, custom_field) do
     case find_cfv(member, custom_field) do
       nil -> nil
-      cfv -> extract_sort_value(cfv.value, custom_field.value_type)
+      cfv -> CustomFieldSort.sort_key(cfv.value, custom_field.value_type)
     end
   end
 
@@ -670,15 +675,4 @@ defmodule MvWeb.MemberExportController do
     |> String.split()
     |> Enum.map_join(" ", &String.capitalize/1)
   end
-
-  defp extract_sort_value(%Ash.Union{value: value, type: type}, _),
-    do: extract_sort_value(value, type)
-
-  defp extract_sort_value(nil, _), do: nil
-  defp extract_sort_value(value, :string) when is_binary(value), do: value
-  defp extract_sort_value(value, :integer) when is_integer(value), do: value
-  defp extract_sort_value(value, :boolean) when is_boolean(value), do: value
-  defp extract_sort_value(%Date{} = d, :date), do: d
-  defp extract_sort_value(value, :email) when is_binary(value), do: value
-  defp extract_sort_value(value, _), do: to_string(value)
 end