Show ancestor iterations in subgroups

Users should be able to view reports for ancestor iterations
so they must first be able to see them in the iterations list

ee/app/assets/javascripts/iterations/queries/iterations.query.graphql

@@ -13,7 +13,6 @@ query Iterations(
   group(fullPath: $fullPath) @include(if: $isGroup) {
     iterations(
       state: $state
-      includeAncestors: false
       before: $beforeCursor
       after: $afterCursor
       first: $firstPageSize

ee/changelogs/unreleased/222763-show-ancestor-iterations-in-subgroups.yml

+---
+title: Show ancestor iterations in subgroups
+merge_request: 40990
+author:
+type: changed

ee/spec/features/groups/iterations/iterations_list_spec.rb

@@ -5,12 +5,15 @@ require 'spec_helper'
 RSpec.describe 'Iterations list', :js do
   let(:now) { Time.now }
   let_it_be(:group) { create(:group) }
+  let_it_be(:subgroup) { create(:group, parent: group) }
   let_it_be(:user) { create(:user) }
   let!(:started_iteration) { create(:iteration, :skip_future_date_validation, group: group, start_date: now - 1.day, due_date: now, title: 'Started iteration') }
   let!(:upcoming_iteration) { create(:iteration, group: group, start_date: now + 1.day, due_date: now + 2.days) }
   let!(:closed_iteration) { create(:closed_iteration, :skip_future_date_validation, group: group, start_date: now - 3.days, due_date: now - 2.days) }
+  let!(:subgroup_iteration) { create(:iteration, :skip_future_date_validation, group: subgroup, start_date: now - 5.days, due_date: now - 4.days) }
 
   context 'as guest' do
+    context 'when in group' do
       before do
         visit group_iterations_path(group)
       end
@@ -23,18 +26,21 @@ RSpec.describe 'Iterations list', :js do
         expect(page).to have_link(started_iteration.title)
         expect(page).to have_link(upcoming_iteration.title)
         expect(page).not_to have_link(closed_iteration.title)
+        expect(page).not_to have_link(subgroup_iteration.title)
 
         click_link('Closed')
 
         expect(page).to have_link(closed_iteration.title)
         expect(page).not_to have_link(started_iteration.title)
         expect(page).not_to have_link(upcoming_iteration.title)
+        expect(page).not_to have_link(subgroup_iteration.title)
 
         click_link('All')
 
         expect(page).to have_link(started_iteration.title)
         expect(page).to have_link(upcoming_iteration.title)
         expect(page).to have_link(closed_iteration.title)
+        expect(page).not_to have_link(subgroup_iteration.title)
       end
 
       context 'when an iteration is clicked' do
@@ -48,6 +54,34 @@ RSpec.describe 'Iterations list', :js do
       end
     end
 
+    context 'when in subgroup' do
+      before do
+        visit group_iterations_path(subgroup)
+      end
+
+      it 'shows iterations on each tab including ancestor iterations' do
+        expect(page).to have_link(started_iteration.title)
+        expect(page).to have_link(upcoming_iteration.title)
+        expect(page).not_to have_link(closed_iteration.title)
+        expect(page).to have_link(subgroup_iteration.title)
+
+        click_link('Closed')
+
+        expect(page).to have_link(closed_iteration.title)
+        expect(page).not_to have_link(started_iteration.title)
+        expect(page).not_to have_link(upcoming_iteration.title)
+        expect(page).not_to have_link(subgroup_iteration.title)
+
+        click_link('All')
+
+        expect(page).to have_link(started_iteration.title)
+        expect(page).to have_link(upcoming_iteration.title)
+        expect(page).to have_link(closed_iteration.title)
+        expect(page).to have_link(subgroup_iteration.title)
+      end
+    end
+  end
+
   context 'as user' do
     before do
       stub_licensed_features(iterations: true)