Remove custom field from query in session

lib/open_project/reporting/patches/custom_fields_controller_patch.rb

@@ -36,29 +36,52 @@ module OpenProject::Reporting::Patches
       def destroy_with_custom_fields
         id = @custom_field.id
 
-        if @custom_field.destroyed?
-          custom_field_name = "CustomField#{id}"
-          reports = CostQuery.where("serialized LIKE '%CustomField#{id}%'")
-
-          reports.each do |report|
-            filters = report.serialized[:filters].reject { |f| f[0] == custom_field_name }
-            group_bys = report.serialized[:group_bys].reject { |f| f[0] == custom_field_name }
-            updated_report = build_query(report.engine, filters, group_bys)
-            report.migrate(updated_report)
-            report.save!
-          end
-        end
+        reports = CostQuery.where("serialized LIKE '%CustomField#{id}%'")
+
+        remove_custom_field_from_cost_report(reports, id)
+        remove_custom_field_from_session(id)
 
         destroy_without_custom_fields
       end
 
       private
 
+      def remove_custom_field_from_cost_report(affected_reports, id)
+        custom_field_name = "CustomField#{id}"
+
+        affected_reports.each do |report|
+          filters = reject_from_query_properties(report, :filters, custom_field_name)
+          group_bys = reject_from_query_properties(report, :group_bys, custom_field_name)
+          updated_report = build_query(report.engine, filters, group_bys)
+          report.migrate(updated_report)
+          report.save!
+        end
+      end
+
+      def reject_from_query_properties(report, property, custom_field_name)
+        report.serialized[property].reject { |f| f[0] == custom_field_name }
+      end
+
       def build_query(report_engine, filters, groups = {})
         query = report_engine.deserialize({ filters: filters, group_bys: groups })
         query.serialize
         query
       end
+
+      def remove_custom_field_from_session(id)
+        custom_field_name = "custom_field#{id}".to_sym
+        report_engine_name = CostQuery.name.underscore.to_sym
+        cookie = session[report_engine_name]
+
+        if cookie
+          cookie[:filters][:operators].delete(custom_field_name)
+          cookie[:filters][:values].delete(custom_field_name)
+          cookie[:groups][:rows].delete(custom_field_name.to_s)
+          cookie[:groups][:columns].delete(custom_field_name.to_s)
+
+          session[report_engine_name] = cookie
+        end
+      end
     end
   end
 end