Extract permitted attributes to separate service

app/controllers/admin/subscriptions_controller.rb

@@ -157,18 +157,7 @@ module Admin
     end
 
     def subscription_params
-      return params[:subscription] if params[:subscription].empty?
-
-      params.require(:subscription).permit(
-        :id, :shop_id, :schedule_id, :customer_id,
-        :payment_method_id, :shipping_method_id,
-        :begins_at, :ends_at,
-        :canceled_at, :paused_at,
-        :shipping_fee_estimate, :payment_fee_estimate,
-        :subscription_line_items_attributes => [:id, :quantity, :variant_id, :price_estimate, :_destroy],
-        :bill_address_attributes => permitted_address_attributes,
-        :ship_address_attributes => permitted_address_attributes
-      )
+      PermittedAttributes::Subscription.new(params).call
     end
   end
 end

app/services/permitted_attributes/subscription.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module PermittedAttributes
+  class Subscription
+    def initialize(params)
+      @params = params
+    end
+
+    def call
+      return @params[:subscription] if @params[:subscription].empty?
+
+      @params.require(:subscription).permit(basic_permitted_attributes + other_permitted_attributes)
+    end
+
+    private
+
+    def basic_permitted_attributes
+      [
+        :id, :shop_id, :schedule_id, :customer_id,
+        :payment_method_id, :shipping_method_id,
+        :begins_at, :ends_at,
+        :canceled_at, :paused_at,
+        :shipping_fee_estimate, :payment_fee_estimate,
+      ]
+    end
+
+    def other_permitted_attributes
+      [
+        subscription_line_items_attributes: [
+          :id, :quantity, :variant_id, :price_estimate, :_destroy
+        ],
+        bill_address_attributes: PermittedAttributes::Address.attributes,
+        ship_address_attributes: PermittedAttributes::Address.attributes
+      ]
+    end
+  end
+end