Add timestamps to user_preferences table. Thus we know when the cache…

…d styles are invalid and needs to be reloaded.

app/helpers/highlighting_helper.rb

@@ -4,6 +4,6 @@ def highlight_css_version_tag(max_updated_at = highlight_css_updated_at)
   end
 
   def highlight_css_updated_at
-    ApplicationRecord.most_recently_changed Status, IssuePriority, Type
+    ApplicationRecord.most_recently_changed Status, IssuePriority, Type, UserPreference
   end
 end

db/migrate/20240703131639_add_timestamps_to_user_preferences.rb

@@ -0,0 +1,5 @@
+class AddTimestampsToUserPreferences < ActiveRecord::Migration[7.1]
+  def change
+    add_timestamps :user_preferences, default: DateTime.now
+  end
+end

spec/models/user_preference_spec.rb

@@ -61,24 +61,6 @@
     end
   end
 
-  describe "#respond_to?" do
-    context "for created_at (key not in the schema)" do
-      it "is does not respond" do
-        expect(preference)
-          .not_to respond_to(:created_at)
-      end
-    end
-  end
-
-  describe "an unsupported method" do
-    context "for created_at (key not in the schema)" do
-      it "raises an error" do
-        expect { preference.created_at }
-          .to raise_error NoMethodError
-      end
-    end
-  end
-
   describe "sort order" do
     it_behaves_like "accepts real and false booleans",
                     :comments_in_reverse_order=,