Allow users to add cluster with ancestors

Include a new policy in Clusterables
(projects and groups), which checks if another cluster
can be added

clusterable_has_cluster? and multiple_clusters_available
private methods will be overriden in EE

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/34758

1 files changed, 37 insertions, 0 deletions

diff --git a/spec/support/shared_examples/policies/clusterable_shared_examples.rb b/spec/support/shared_examples/policies/clusterable_shared_examples.rb
new file mode 100644
index 00000000000..d99f94c76c3
--- /dev/null
+++ b/spec/support/shared_examples/policies/clusterable_shared_examples.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+shared_examples 'clusterable policies' do
+  describe '#add_cluster?' do
+    let(:current_user) { create(:user) }
+
+    subject { described_class.new(current_user, clusterable) }
+
+    context 'with a developer' do
+      before do
+        clusterable.add_developer(current_user)
+      end
+
+      it { expect_disallowed(:add_cluster) }
+    end
+
+    context 'with a maintainer' do
+      before do
+        clusterable.add_maintainer(current_user)
+      end
+
+      context 'with no clusters' do
+        it { expect_allowed(:add_cluster) }
+      end
+
+      context 'with an existing cluster' do
+        before do
+          cluster
+        end
+
+        it { expect_disallowed(:add_cluster) }
+      end
+    end
+  end
+end