Render ordering button for opposite direction

ee/app/helpers/ee/sorting_helper.rb

@@ -3,6 +3,9 @@ module EE
   module SortingHelper
     extend ::Gitlab::Utils::Override
 
+    ORDER_ASC = 'asc'.freeze
+    ORDER_DESC = 'desc'.freeze
+
     override :sort_options_hash
     def sort_options_hash
       {
@@ -16,13 +19,38 @@ module EE
 
     def epics_sort_options_hash
       {
+        sort_value_oldest_created => sort_title_created_date,
         sort_value_recently_created => sort_title_created_date,
+        sort_value_oldest_updated => sort_title_recently_updated,
         sort_value_recently_updated => sort_title_recently_updated,
-        sort_value_start_date  => sort_title_start_date,
+        sort_value_start_date_later => sort_title_start_date,
+        sort_value_start_date_soon => sort_title_start_date,
+        sort_value_end_date_later => sort_title_end_date,
         sort_value_end_date => sort_title_end_date
       }
     end
 
+    # This method is used to find the opposite ordering parameter for the sort button in the UI.
+    # Hash key is the descending sorting order and the sort value is the opposite of it for the same field.
+    # For example: created_at_asc => created_at_desc
+    def epics_ordering_options_hash
+      {
+        sort_value_oldest_created => sort_value_recently_created,
+        sort_value_oldest_updated => sort_value_recently_updated,
+        sort_value_start_date_soon => sort_value_start_date_later,
+        sort_value_end_date => sort_value_end_date_later
+
+      }
+    end
+
+    # Creates a button with the opposite ordering for the current field in UI.
+    def sort_order_button(sort)
+      opposite_sorting_param = epics_ordering_options_hash[sort] || epics_ordering_options_hash.key(sort)
+      sort_icon = sort.end_with?('desc') ? 'sort-highest' : ' sort-lowest'
+
+      link_to sort_icon, page_filter_path(sort: opposite_sorting_param, label: true)
+    end
+
     def sort_title_start_date
       s_('SortOptions|Start date')
     end

ee/app/models/ee/epic.rb

@@ -58,6 +58,10 @@ module EE
         reorder(::Gitlab::Database.nulls_last_order('end_date', 'DESC'), 'id DESC')
       end
 
+      scope :order_start_date_desc, -> do
+        reorder(::Gitlab::Database.nulls_last_order('start_date', 'DESC'), 'id DESC')
+      end
+
       def etag_caching_enabled?
         true
       end
@@ -106,6 +110,7 @@ module EE
         case method.to_s
         when 'start_or_end_date' then order_start_or_end_date_asc
         when 'start_date_asc' then order_start_date_asc
+        when 'start_date_desc' then order_start_date_desc
         when 'end_date_asc' then order_end_date_asc
         when 'end_date_desc' then order_end_date_desc
         else

ee/app/views/shared/epic/_sort_dropdown.html.haml

@@ -9,12 +9,9 @@
       %li
         = sortable_item(sort_title_created_date, page_filter_path(sort: sort_value_recently_created, label: true), sorted_by)
         = sortable_item(sort_title_recently_updated, page_filter_path(sort: sort_value_recently_updated, label: true), sorted_by)
-        = sortable_item(sort_title_start_date, page_filter_path(sort: sort_value_start_date, label: true), sorted_by)
-        = sortable_item(sort_title_end_date, page_filter_path(sort: sort_value_end_date, label: true), sorted_by)
+        = sortable_item(sort_title_start_date, page_filter_path(sort: sort_value_start_date_later, label: true), sorted_by)
+        = sortable_item(sort_title_end_date, page_filter_path(sort: sort_value_end_date_later, label: true), sorted_by)
     %button.dropdown-toggle-split.pt-2{ type: 'button' }
-      = sprite_icon('sort-highest', size: 16)
-      -# = sprite_icon('sort-lowest', size: 16)
-      = sorted_by
-      = |
-      = @sort
-
+      = sort_order_button(@sort)
+      -#= sprite_icon('sort-highest', size: 16)
+      -#= sprite_icon('sort-lowest', size: 16)

ee/spec/features/epics/epics_list_spec.rb

@@ -67,7 +67,6 @@ describe 'epics list', :js do
 
     it 'sorts by the selected value and stores the selection for epic list & roadmap' do
       page.within('.epics-other-filters') do
-        live_debug
         click_button 'Due date'
         sort_options = find('ul.dropdown-menu-sort li').all('a').collect(&:text)