Resolve "Show plan of parent group on subgroup details page"

ee/app/models/ee/namespace.rb

@@ -142,9 +142,12 @@ module EE
 
     def actual_plan
       strong_memoize(:actual_plan) do
-        subscription = find_or_create_subscription
-
-        subscription&.hosted_plan || Plan.free || Plan.default
+        if parent_id
+          root_ancestor.actual_plan
+        else
+          subscription = find_or_create_subscription
+          subscription&.hosted_plan || Plan.free || Plan.default
+        end
       end
     end
 

ee/app/views/admin/_namespace_plan_badge.html.haml

 - namespace = local_assigns.fetch(:namespace)
 - return unless Gitlab::CurrentSettings.should_check_namespace_plan? && namespace.actual_plan&.paid?
 
-%span.plan-badge.has-tooltip{ data: { plan: namespace.actual_plan.name }, title: "#{namespace.actual_plan.title} Plan" }
+%span.plan-badge.has-tooltip{ data: { plan: namespace.actual_plan_name }, title: "#{namespace.actual_plan.title} Plan" }
   = custom_icon('icon_premium')

ee/app/views/admin/_namespace_plan_info.html.haml

@@ -4,7 +4,7 @@
 %li
   %span.light Plan:
   - if namespace.actual_plan&.paid?
-    %strong.plan-badge.inline{ data: { plan: namespace.actual_plan.name } }
+    %strong.plan-badge.inline{ data: { plan: namespace.actual_plan_name } }
       = custom_icon('icon_premium')
       = namespace.actual_plan.title
   - else

ee/changelogs/unreleased/8831-show-plan-of-parent-group-on-subgroup-details-page.yml

+---
+title: Resolve Show plan of root group on subgroup details page
+merge_request: 20218
+author:
+type: added

ee/lib/ee/api/entities.rb

@@ -147,7 +147,7 @@ module EE
             namespace.billable_members_count(options[:requested_hosted_plan])
           end
           expose :plan, if: ->(namespace, opts) { ::Ability.allowed?(opts[:current_user], :admin_namespace, namespace) } do |namespace, _|
-            namespace.actual_plan&.name
+            namespace.actual_plan_name
           end
         end
       end

ee/spec/models/namespace_spec.rb

@@ -668,6 +668,32 @@ describe Namespace do
           expect(namespace.gitlab_subscription).to be_present
         end
       end
+
+      context 'when namespace is a subgroup with a parent' do
+        let(:subgroup) { create(:namespace, parent: namespace) }
+
+        context 'when free plan does exist' do
+          before do
+            free_plan
+          end
+
+          it 'does not generates a subscription' do
+            expect(subgroup.actual_plan).to eq(free_plan)
+            expect(subgroup.gitlab_subscription).not_to be_present
+          end
+        end
+
+        context 'when namespace has a subscription associated' do
+          before do
+            create(:gitlab_subscription, namespace: namespace, hosted_plan: gold_plan)
+          end
+
+          it 'returns the plan from the subscription' do
+            expect(subgroup.actual_plan).to eq(gold_plan)
+            expect(subgroup.gitlab_subscription).not_to be_present
+          end
+        end
+      end
     end
   end
 
@@ -687,6 +713,26 @@ describe Namespace do
         expect(namespace.actual_plan_name).to eq 'free'
       end
     end
+
+    context 'when namespace is a subgroup with a parent' do
+      let(:subgroup) { create(:namespace, parent: namespace) }
+
+      context 'when namespace has a subscription associated' do
+        before do
+          create(:gitlab_subscription, namespace: namespace, hosted_plan: gold_plan)
+        end
+
+        it 'returns an associated plan name' do
+          expect(subgroup.actual_plan_name).to eq 'gold'
+        end
+      end
+
+      context 'when namespace does not have subscription associated' do
+        it 'returns a free plan name' do
+          expect(subgroup.actual_plan_name).to eq 'free'
+        end
+      end
+    end
   end
 
   describe '#billable_members_count' do