EE: Allow group cluster to match environment scope

Add specs too for deploying a group cluster for EE

Tidy specs for readability

ee/app/models/concerns/ee/deployment_platform.rb

@@ -12,5 +12,18 @@ module EE
         .on_environment(environment)
         .last&.platform_kubernetes
     end
+
+    override :find_group_cluster_platform_kubernetes
+    def find_group_cluster_platform_kubernetes(environment: nil)
+      return super unless environment && feature_available?(:multiple_clusters)
+
+      # on_environment use CASE which returns numbers in descending order
+      # So we have to use `hierarchy_order: :desc` + last
+      ::Clusters::Cluster
+        .enabled
+        .on_environment(environment)
+        .ancestor_clusters_for_clusterable(self, hierarchy_order: :desc)
+        .last&.platform_kubernetes
+    end
   end
 end

ee/spec/models/concerns/ee/deployment_platform_spec.rb

@@ -2,7 +2,8 @@ require 'rails_helper'
 
 describe EE::DeploymentPlatform do
   describe '#deployment_platform' do
-    let(:project) { create(:project) }
+    let(:group) { create(:group) }
+    let(:project) { create(:project, group: group) }
 
     shared_examples 'matching environment scope' do
       context 'when multiple clusters license is available' do
@@ -48,10 +49,88 @@ describe EE::DeploymentPlatform do
       end
     end
 
+    context 'when project does not have a cluster but has group clusters' do
+      let!(:default_cluster) do
+        create(:cluster, :provided_by_user,
+               cluster_type: :group_type, groups: [group], environment_scope: '*')
+      end
+
+      let!(:cluster) do
+        create(:cluster, :provided_by_user,
+               cluster_type: :group_type, environment_scope: 'review/*', groups: [group])
+      end
+
+      let(:environment) { 'review/name' }
+
+      subject { project.deployment_platform(environment: environment) }
+
+      context 'when environment scope is exactly matched' do
+        before do
+          cluster.update!(environment_scope: 'review/name')
+        end
+
+        it_behaves_like 'matching environment scope'
+      end
+
+      context 'when environment scope is matched by wildcard' do
+        before do
+          cluster.update!(environment_scope: 'review/*')
+        end
+
+        it_behaves_like 'matching environment scope'
+      end
+
+      context 'when environment scope does not match' do
+        before do
+          cluster.update!(environment_scope: 'review/*/special')
+        end
+
+        it_behaves_like 'not matching environment scope'
+      end
+
+      context 'when group belongs to a parent group' do
+        let(:parent_group) { create(:group) }
+        let(:group) { create(:group, parent: parent_group) }
+
+        context 'when parent_group has a cluster with default scope' do
+          let!(:parent_group_cluster) do
+            create(:cluster, :provided_by_user,
+                   cluster_type: :group_type, environment_scope: '*', groups: [parent_group])
+          end
+
+          it_behaves_like 'matching environment scope'
+        end
+
+        context 'when parent_group has a cluster that is an exact match' do
+          let!(:parent_group_cluster) do
+            create(:cluster, :provided_by_user,
+                   cluster_type: :group_type, environment_scope: 'review/name', groups: [parent_group])
+          end
+
+          it_behaves_like 'matching environment scope'
+        end
+      end
+
+      context 'when feature flag disabled' do
+        before do
+          stub_feature_flags(group_clusters: false)
+        end
+
+        it 'returns nil' do
+          expect(subject).to be_nil
+        end
+      end
+    end
+
     context 'when environment is specified' do
       let!(:default_cluster) { create(:cluster, :provided_by_user, projects: [project], environment_scope: '*') }
       let!(:cluster) { create(:cluster, :provided_by_user, environment_scope: 'review/*', projects: [project]) }
 
+      let!(:group_default_cluster) do
+        create(:cluster, :provided_by_user,
+               cluster_type: :group_type, groups: [group], environment_scope: '*')
+      end
+
       let(:environment) { 'review/name' }
 
       subject { project.deployment_platform(environment: environment) }