1 files changed, 39 insertions, 0 deletions
diff --git a/rubocop/cop/gitlab/namespaced_class.rb b/rubocop/cop/gitlab/namespaced_class.rb
new file mode 100644
index 00000000000..1f1fd280922
--- /dev/null
+++ b/rubocop/cop/gitlab/namespaced_class.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Gitlab
+      # Cop that enforces use of namespaced classes in order to better identify
+      # high level domains within the codebase.
+
+      # @example
+      #   # bad
+      #   class MyClass
+      #   end
+      #
+      #   # good
+      #   module MyDomain
+      #     class MyClass
+      #     end
+      #   end
+
+      class NamespacedClass < RuboCop::Cop::Cop
+        MSG = 'Classes must be declared inside a module indicating a product domain namespace. For more info: https://gitlab.com/gitlab-org/gitlab/-/issues/212156'
+
+        def_node_matcher :compact_namespaced_class?, <<~PATTERN
+          (class (const (const ...) ...) ...)
+        PATTERN
+
+        def on_module(node)
+          @namespaced = true
+        end
+
+        def on_class(node)
+          return if @namespaced
+
+          add_offense(node) unless compact_namespaced_class?(node)
+        end
+      end
+    end
+  end
+end