1 files changed, 21 insertions, 0 deletions
diff --git a/spec/support/shared_examples/namespaces/hierarchy_examples.rb b/spec/support/shared_examples/namespaces/hierarchy_examples.rb
new file mode 100644
index 00000000000..d5754f47be2
--- /dev/null
+++ b/spec/support/shared_examples/namespaces/hierarchy_examples.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+RSpec.shared_examples 'hierarchy with traversal_ids' do
+  # A convenient null node to represent the parent of root.
+  let(:null_node) { double(traversal_ids: []) }
+
+  # Walk the tree to assert that the current_node's traversal_id is always
+  # present and equal to it's parent's traversal_ids plus it's own ID.
+  def validate_traversal_ids(current_node, parent = null_node)
+    expect(current_node.traversal_ids).to be_present
+    expect(current_node.traversal_ids).to eq parent.traversal_ids + [current_node.id]
+
+    current_node.children.each do |child|
+      validate_traversal_ids(child, current_node)
+    end
+  end
+
+  it 'will be valid' do
+    validate_traversal_ids(root)
+  end
+end