Handle non-numeric order in _ct_after_save (#486)

Only run reorder/scope-change logic when the order column is numeric. 

The _ct_after_save flow was restructured to guard calls to _ct.scope_changed? and sibling reordering with _ct.order_is_numeric?, preventing errors when models use a non-numeric order column.

Author: sampatbadhe

lib/closure_tree/hierarchy_maintenance.rb

@@ -41,16 +41,16 @@ def _ct_before_save
     end
 
     def _ct_after_save
-      scope_changed = _ct.order_is_numeric? && _ct.scope_changed?(self)
-
       if saved_changes[_ct.parent_column_name] || @was_new_record
         rebuild!
-      elsif scope_changed
-        # Scope changed without parent change - reorder old scope's siblings
-        _ct_reorder_prior_siblings_if_parent_changed
-        _ct_reorder_siblings
-      elsif _ct.order_option? && saved_changes[_ct.order_column_sym]
-        _ct_reorder_siblings(saved_changes[_ct.order_column_sym].min)
+      elsif _ct.order_is_numeric?
+        if _ct.scope_changed?(self)
+          # Scope changed without parent change - reorder old scope's siblings
+          _ct_reorder_prior_siblings_if_parent_changed
+          _ct_reorder_siblings
+        elsif saved_changes[_ct.order_column_sym]
+          _ct_reorder_siblings(saved_changes[_ct.order_column_sym].min)
+        end
       end
       if saved_changes[_ct.parent_column_name] && !@was_new_record
         # Resetting the ancestral collections addresses

test/closure_tree/hierarchy_maintenance_test.rb

@@ -16,6 +16,14 @@
     end
   end
 
+  describe '#_ct_after_save' do
+    it 'does not raise when updating a node with non-numeric order column' do
+      tag = Tag.create!(name: 'Alpha')
+      tag.update!(name: 'Beta')
+      assert_equal 'Beta', tag.reload.name
+    end
+  end
+
   describe '.cleanup!' do
     before do
       @parent = Metal.create(value: 'parent metal')