Use JSON type for sorting parameter (halfway)

app/finders/pipelines_finder.rb

@@ -108,16 +108,20 @@ class PipelinesFinder
   end
 
   def sort_items(items)
-    order_by = if %w[id status ref user_id].include?(params[:order_by]) # Allow only indexed columns
-                 params[:order_by]
+    return items.order(id: :desc) unless params[:sort].present?
+    params[:sort].each do |s|
+      order_by = if %w[id status ref user_id].include?(s['order_by']) # Allow only indexed columns
+                   s['order_by']
                  else
                    :id
                  end
-    sort = if params[:sort] =~ /\A(ASC|DESC)\z/i
-             params[:sort]
+      sort = if s['asc_desc'] =~ /\A(ASC|DESC)\z/i
+               s['asc_desc']
              else
                :desc
              end
-    items.order(order_by => sort)
+      items = items.order(order_by => sort)
+    end
+    items
   end
 end

lib/api/pipelines.rb

@@ -22,10 +22,10 @@ module API
         optional :yaml_errors, type: Boolean, desc: 'If true, returns only yaml error pipelines'
         optional :name,     type: String, desc: 'The name of user who triggered pipelines'
         optional :username, type: String, desc: 'The username of user who triggered pipelines'
-        optional :order_by, type: String, values: %w[id status ref user_id], default: 'id',
-                            desc: 'The order_by which is combined with a sort'
-        optional :sort,     type: String, values: %w[asc desc], default: 'desc',
-                            desc: 'The sort method which is combined with an order_by'
+        optional :sort,     type: JSON, desc: 'order_by and asc_desc' do
+          requires :order_by, type: String, values: %w[id status ref user_id]
+          requires :asc_desc, type: String, values: %w[asc desc]
+        end
       end
       get ':id/pipelines' do
         authorize! :read_pipeline, user_project