Check behaviour when adding more than one cluster

spec/services/clusters/create_service_spec.rb

@@ -7,6 +7,7 @@ describe Clusters::CreateService do
   let(:result) { described_class.new(project, user, params).execute(access_token) }
 
   context 'when provider is gcp' do
+    context 'when project has no clusters' do
       context 'when correct params' do
         let(:params) do
           {
@@ -61,4 +62,29 @@ describe Clusters::CreateService do
         end
       end
     end
+
+    context 'when project has a cluster' do
+      let(:params) do
+        {
+          name: 'test-cluster',
+          provider_type: :gcp,
+          provider_gcp_attributes: {
+            gcp_project_id: 'gcp-project',
+            zone: 'us-central1-a',
+            num_nodes: 1,
+            machine_type: 'machine_type-a'
+          }
+        }
+      end
+
+      before do
+        Clusters::Cluster.create(params.merge(user: user, projects: [project]))
+      end
+
+      it 'does not create a cluster' do
+        expect(ClusterProvisionWorker).not_to receive(:perform_async)
+        expect { result }.to change { Clusters::Cluster.count }.by(0)
+      end
+    end
+  end
 end