From b1212b6d0e45478aa07288a102695f32d9e19f4a Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Tue, 24 Nov 2020 06:47:51 +0900
Subject: [PATCH] Import `EnforceSuperclass` module

---
 lib/rubocop/cop/mixin/enforce_superclass.rb | 32 +++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 lib/rubocop/cop/mixin/enforce_superclass.rb

diff --git a/lib/rubocop/cop/mixin/enforce_superclass.rb b/lib/rubocop/cop/mixin/enforce_superclass.rb
new file mode 100644
index 0000000000..1667e78312
--- /dev/null
+++ b/lib/rubocop/cop/mixin/enforce_superclass.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Common functionality for enforcing a specific superclass.
+    module EnforceSuperclass
+      def self.included(base)
+        base.def_node_matcher :class_definition, <<~PATTERN
+          (class (const _ !:#{base::SUPERCLASS}) #{base::BASE_PATTERN} ...)
+        PATTERN
+
+        base.def_node_matcher :class_new_definition, <<~PATTERN
+          [!^(casgn {nil? cbase} :#{base::SUPERCLASS} ...)
+           !^^(casgn {nil? cbase} :#{base::SUPERCLASS} (block ...))
+           (send (const {nil? cbase} :Class) :new #{base::BASE_PATTERN})]
+        PATTERN
+      end
+
+      def on_class(node)
+        class_definition(node) do
+          add_offense(node.children[1])
+        end
+      end
+
+      def on_send(node)
+        class_new_definition(node) do
+          add_offense(node.children.last)
+        end
+      end
+    end
+  end
+end