fix linting

lib/mv_web/controllers/member_export_controller.ex

@@ -96,18 +96,21 @@ defmodule MvWeb.MemberExportController do
 
   defp filter_existing_atoms(list) when is_list(list) do
     list
-    |> Enum.filter(&is_binary/1)
     |> Enum.filter(fn name ->
-      try do
-        _ = String.to_existing_atom(name)
-        true
-      rescue
-        ArgumentError -> false
-      end
+      is_binary(name) and atom_exists?(name)
     end)
     |> Enum.uniq()
   end
 
+  defp atom_exists?(name) do
+    try do
+      _ = String.to_existing_atom(name)
+      true
+    rescue
+      ArgumentError -> false
+    end
+  end
+
   defp extract_list(params, key) do
     case Map.get(params, key) do
       list when is_list(list) -> list
@@ -215,13 +218,17 @@ defmodule MvWeb.MemberExportController do
 
   defp build_custom_fields_by_id(custom_field_ids, custom_fields) do
     Enum.reduce(custom_field_ids, %{}, fn id, acc ->
-      case Enum.find(custom_fields, fn cf -> to_string(cf.id) == to_string(id) end) do
-        nil -> acc
-        cf -> Map.put(acc, id, cf)
-      end
+      find_and_add_custom_field(acc, id, custom_fields)
     end)
   end
 
+  defp find_and_add_custom_field(acc, id, custom_fields) do
+    case Enum.find(custom_fields, fn cf -> to_string(cf.id) == to_string(id) end) do
+      nil -> acc
+      cf -> Map.put(acc, id, cf)
+    end
+  end
+
   defp load_members_for_export(actor, parsed, custom_fields_by_id) do
     select_fields = [:id] ++ Enum.map(parsed.selectable_member_fields, &String.to_existing_atom/1)
 
@@ -322,19 +329,17 @@ defmodule MvWeb.MemberExportController do
   defp maybe_sort_export(query, _field, nil), do: {query, false}
 
   defp maybe_sort_export(query, field, order) when is_binary(field) do
-    cond do
-      custom_field_sort?(field) ->
-        # Custom field sort → in-memory nach dem Read (wie Tabelle)
-        {query, true}
+    if custom_field_sort?(field) do
+      # Custom field sort → in-memory nach dem Read (wie Tabelle)
+      {query, true}
+    else
+      field_atom = String.to_existing_atom(field)
 
-      true ->
-        field_atom = String.to_existing_atom(field)
-
-        if field_atom in (Mv.Constants.member_fields() -- [:notes]) do
-          {Ash.Query.sort(query, [{field_atom, String.to_existing_atom(order)}]), false}
-        else
-          {query, false}
-        end
+      if field_atom in (Mv.Constants.member_fields() -- [:notes]) do
+        {Ash.Query.sort(query, [{field_atom, String.to_existing_atom(order)}]), false}
+      else
+        {query, false}
+      end
     end
   rescue
     ArgumentError -> {query, false}
@@ -372,12 +377,7 @@ defmodule MvWeb.MemberExportController do
 
       sorted_with_values =
         Enum.sort_by(with_values, fn member ->
-          member
-          |> find_cfv(custom_field)
-          |> case do
-            nil -> nil
-            cfv -> extract_sort_value(cfv.value, custom_field.value_type)
-          end
+          extract_member_sort_value(member, custom_field)
         end)
 
       sorted_with_values =
@@ -415,6 +415,13 @@ defmodule MvWeb.MemberExportController do
     end)
   end
 
+  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)
+    end
+  end
+
   defp build_columns(conn, parsed, custom_fields_by_id) do
     member_cols =
       Enum.map(parsed.selectable_member_fields, fn field ->