CSV export: robust apply_export_filters, single custom_field_ids_union, string boolean_filters, more tests

lib/mv_web/controllers/member_export_controller.ex

@@ -197,8 +197,7 @@ defmodule MvWeb.MemberExportController do
       parsed
       |> ensure_sort_custom_field_loaded()
 
-    with {:ok, custom_fields_by_id} <-
+    with {:ok, custom_fields_by_id} <- load_custom_fields_by_id(parsed.custom_field_ids_union, actor),
-           load_custom_fields_by_id(parsed.custom_field_ids_union, actor),
          {:ok, members} <- load_members_for_export(actor, parsed, custom_fields_by_id) do
       columns = build_columns(conn, parsed, custom_fields_by_id)
       csv_iodata = MembersCSV.export(members, columns)
@@ -216,18 +215,15 @@ defmodule MvWeb.MemberExportController do
     end
   end
 
-  defp ensure_sort_custom_field_loaded(
+  defp ensure_sort_custom_field_loaded(%{custom_field_ids: ids, custom_field_ids_union: union, sort_field: sort_field} = parsed) do
-         %{custom_field_ids: ids, custom_field_ids_union: union, sort_field: sort_field} = parsed
-       ) do
     case extract_sort_custom_field_id(sort_field) do
       nil ->
         parsed
 
       id ->
-        %{
+        %{parsed |
-          parsed
+          custom_field_ids: Enum.uniq([id | ids]),
-          | custom_field_ids: Enum.uniq([id | ids]),
+          custom_field_ids_union: Enum.uniq([id | union])
-            custom_field_ids_union: Enum.uniq([id | union])
         }
     end
   end