Allow issues to be sorted by relative_position

- adding a "Manual" option to the dropdown
- show 100 issues list when manually sorting

app/controllers/concerns/issuable_collections.rb

@@ -41,6 +41,7 @@ module IssuableCollections
     return if pagination_disabled?
 
     @issuables          = @issuables.page(params[:page])
+    @issuables          = per_page_for_relative_position if params[:sort] == 'relative_position'
     @issuable_meta_data = issuable_meta_data(@issuables, collection_type)
     @total_pages        = issuable_page_count
   end
@@ -80,6 +81,11 @@ module IssuableCollections
     (row_count.to_f / limit).ceil
   end
 
+  # manual / relative_position sorting allows for 100 items on the page
+  def per_page_for_relative_position
+    @issuables.per(100) # rubocop:disable Gitlab/ModuleWithInstanceVariables
+  end
+
   def issuable_finder_for(finder_class)
     finder_class.new(current_user, finder_options)
   end

app/helpers/sorting_helper.rb

@@ -3,29 +3,30 @@
 module SortingHelper
   def sort_options_hash
     {
-      sort_value_created_date     => sort_title_created_date,
-      sort_value_downvotes        => sort_title_downvotes,
-      sort_value_due_date         => sort_title_due_date,
-      sort_value_due_date_later   => sort_title_due_date_later,
-      sort_value_due_date_soon    => sort_title_due_date_soon,
-      sort_value_label_priority   => sort_title_label_priority,
-      sort_value_largest_group    => sort_title_largest_group,
-      sort_value_largest_repo     => sort_title_largest_repo,
-      sort_value_milestone        => sort_title_milestone,
-      sort_value_milestone_later  => sort_title_milestone_later,
-      sort_value_milestone_soon   => sort_title_milestone_soon,
-      sort_value_name             => sort_title_name,
-      sort_value_name_desc        => sort_title_name_desc,
-      sort_value_oldest_created   => sort_title_oldest_created,
-      sort_value_oldest_signin    => sort_title_oldest_signin,
-      sort_value_oldest_updated   => sort_title_oldest_updated,
-      sort_value_recently_created => sort_title_recently_created,
-      sort_value_recently_signin  => sort_title_recently_signin,
-      sort_value_recently_updated => sort_title_recently_updated,
-      sort_value_popularity       => sort_title_popularity,
-      sort_value_priority         => sort_title_priority,
-      sort_value_upvotes          => sort_title_upvotes,
-      sort_value_contacted_date   => sort_title_contacted_date
+      sort_value_created_date      => sort_title_created_date,
+      sort_value_downvotes         => sort_title_downvotes,
+      sort_value_due_date          => sort_title_due_date,
+      sort_value_due_date_later    => sort_title_due_date_later,
+      sort_value_due_date_soon     => sort_title_due_date_soon,
+      sort_value_label_priority    => sort_title_label_priority,
+      sort_value_largest_group     => sort_title_largest_group,
+      sort_value_largest_repo      => sort_title_largest_repo,
+      sort_value_milestone         => sort_title_milestone,
+      sort_value_milestone_later   => sort_title_milestone_later,
+      sort_value_milestone_soon    => sort_title_milestone_soon,
+      sort_value_name              => sort_title_name,
+      sort_value_name_desc         => sort_title_name_desc,
+      sort_value_oldest_created    => sort_title_oldest_created,
+      sort_value_oldest_signin     => sort_title_oldest_signin,
+      sort_value_oldest_updated    => sort_title_oldest_updated,
+      sort_value_recently_created  => sort_title_recently_created,
+      sort_value_recently_signin   => sort_title_recently_signin,
+      sort_value_recently_updated  => sort_title_recently_updated,
+      sort_value_popularity        => sort_title_popularity,
+      sort_value_priority          => sort_title_priority,
+      sort_value_upvotes           => sort_title_upvotes,
+      sort_value_contacted_date    => sort_title_contacted_date,
+      sort_value_relative_position => sort_title_relative_position
     }
   end
 
@@ -397,6 +398,10 @@ module SortingHelper
     s_('SortOptions|Recent last activity')
   end
 
+  def sort_title_relative_position
+    s_('SortOptions|Manual')
+  end
+
   # Values.
   def sort_value_access_level_asc
     'access_level_asc'
@@ -545,4 +550,8 @@ module SortingHelper
   def sort_value_recently_last_activity
     'last_activity_on_desc'
   end
+
+  def sort_value_relative_position
+    'relative_position'
+  end
 end

app/models/issue.rb

@@ -58,6 +58,7 @@ class Issue < ApplicationRecord
   scope :order_due_date_asc, -> { reorder('issues.due_date IS NULL, issues.due_date ASC') }
   scope :order_due_date_desc, -> { reorder('issues.due_date IS NULL, issues.due_date DESC') }
   scope :order_closest_future_date, -> { reorder('CASE WHEN issues.due_date >= CURRENT_DATE THEN 0 ELSE 1 END ASC, ABS(CURRENT_DATE - issues.due_date) ASC') }
+  scope :order_relative_position_asc, -> { reorder(::Gitlab::Database.nulls_last_order('relative_position', 'ASC')) }
 
   scope :preload_associations, -> { preload(:labels, project: :namespace) }
   scope :with_api_entity_associations, -> { preload(:timelogs, :assignees, :author, :notes, :labels, project: [:route, { namespace: :route }] ) }
@@ -130,9 +131,10 @@ class Issue < ApplicationRecord
   def self.sort_by_attribute(method, excluded_labels: [])
     case method.to_s
     when 'closest_future_date' then order_closest_future_date
-    when 'due_date'      then order_due_date_asc
-    when 'due_date_asc'  then order_due_date_asc
-    when 'due_date_desc' then order_due_date_desc
+    when 'due_date'            then order_due_date_asc
+    when 'due_date_asc'        then order_due_date_asc
+    when 'due_date_desc'       then order_due_date_desc
+    when 'relative_position'   then order_relative_position_asc
     else
       super
     end

app/views/shared/issuable/_sort_dropdown.html.haml

@@ -10,12 +10,13 @@
         = icon('chevron-down')
       %ul.dropdown-menu.dropdown-menu-right.dropdown-menu-selectable.dropdown-menu-sort
         %li
-          = sortable_item(sort_title_priority,         page_filter_path(sort: sort_value_priority),         sort_title)
-          = sortable_item(sort_title_created_date,     page_filter_path(sort: sort_value_created_date),     sort_title)
-          = sortable_item(sort_title_recently_updated, page_filter_path(sort: sort_value_recently_updated), sort_title)
-          = sortable_item(sort_title_milestone,        page_filter_path(sort: sort_value_milestone),        sort_title)
-          = sortable_item(sort_title_due_date,         page_filter_path(sort: sort_value_due_date),         sort_title) if viewing_issues
-          = sortable_item(sort_title_popularity,       page_filter_path(sort: sort_value_popularity),       sort_title)
-          = sortable_item(sort_title_label_priority,   page_filter_path(sort: sort_value_label_priority),   sort_title)
+          = sortable_item(sort_title_priority,          page_filter_path(sort: sort_value_priority),          sort_title)
+          = sortable_item(sort_title_created_date,      page_filter_path(sort: sort_value_created_date),      sort_title)
+          = sortable_item(sort_title_recently_updated,  page_filter_path(sort: sort_value_recently_updated),  sort_title)
+          = sortable_item(sort_title_milestone,         page_filter_path(sort: sort_value_milestone),         sort_title)
+          = sortable_item(sort_title_due_date,          page_filter_path(sort: sort_value_due_date),          sort_title) if viewing_issues
+          = sortable_item(sort_title_popularity,        page_filter_path(sort: sort_value_popularity),        sort_title)
+          = sortable_item(sort_title_label_priority,    page_filter_path(sort: sort_value_label_priority),    sort_title)
+          = sortable_item(sort_title_relative_position, page_filter_path(sort: sort_value_relative_position), sort_title) if viewing_issues
           = render_if_exists('shared/ee/issuable/sort_dropdown', viewing_issues: viewing_issues, sort_title: sort_title)
     = issuable_sort_direction_button(sort_value)

changelogs/unreleased/9121-sort-relative-position.yml

+---
+title: Allow issue list to be sorted by relative order
+merge_request: 28566
+author:
+type: added

locale/gitlab.pot

@@ -9061,6 +9061,9 @@ msgstr ""
 msgid "SortOptions|Least popular"
 msgstr ""
 
+msgid "SortOptions|Manual"
+msgstr ""
+
 msgid "SortOptions|Milestone due date"
 msgstr ""
 

spec/controllers/projects/issues_controller_spec.rb

@@ -130,6 +130,37 @@ describe Projects::IssuesController do
       end
     end
 
+    context 'with relative_position sorting' do
+      let!(:issue_list) { create_list(:issue, 2, project: project) }
+
+      before do
+        sign_in(user)
+        project.add_developer(user)
+        allow(Kaminari.config).to receive(:default_per_page).and_return(1)
+      end
+
+      it 'overrides the number allowed on the page' do
+        get :index,
+          params: {
+            namespace_id: project.namespace.to_param,
+            project_id:   project,
+            sort:         'relative_position'
+          }
+
+        expect(assigns(:issues).count).to eq 2
+      end
+
+      it 'allows the default number on the page' do
+        get :index,
+          params: {
+            namespace_id: project.namespace.to_param,
+            project_id:   project
+          }
+
+        expect(assigns(:issues).count).to eq 1
+      end
+    end
+
     context 'external authorization' do
       before do
         sign_in user

spec/models/issue_spec.rb

@@ -93,6 +93,21 @@ describe Issue do
     end
   end
 
+  describe '#sort' do
+    let(:project) { create(:project) }
+
+    context "by relative_position" do
+      let!(:issue)  { create(:issue, project: project) }
+      let!(:issue2) { create(:issue, project: project, relative_position: 2) }
+      let!(:issue3) { create(:issue, project: project, relative_position: 1) }
+
+      it "sorts asc with nulls at the end" do
+        issues = project.issues.sort_by_attribute('relative_position')
+        expect(issues).to eq([issue3, issue2, issue])
+      end
+    end
+  end
+
   describe '#card_attributes' do
     it 'includes the author name' do
       allow(subject).to receive(:author).and_return(double(name: 'Robert'))