Add clear_helpers as a way to clean up all helpers added to this controller, maintaing just the helper with the same name as the controller.

actionpack/lib/abstract_controller/helpers.rb

@@ -95,6 +95,13 @@ module AbstractController
         _helpers.module_eval(&block) if block_given?
       end
 
+      # Clears up all existing helpers in this class, only keeping the helper
+      # with the same name as this class.
+      def clear_helpers
+        self._helpers = Module.new
+        default_helper_module! unless anonymous?
+      end
+
       private
       # Makes all the (instance) methods in the helper module available to templates
       # rendered through this controller.

actionpack/test/abstract/helper_test.rb

@@ -38,6 +38,10 @@ module AbstractController
       end
     end
 
+    class ::HelperyTestController < AbstractHelpers
+      clear_helpers
+    end
+
     class AbstractHelpersBlock < ControllerWithHelpers
       helper do
         include ::AbstractController::Testing::HelperyTest
@@ -45,7 +49,6 @@ module AbstractController
     end
 
     class TestHelpers < ActiveSupport::TestCase
-
       def setup
         @controller = AbstractHelpers.new
       end
@@ -74,8 +77,22 @@ module AbstractController
         @controller.process(:with_module)
         assert_equal "Module Included", @controller.response_body
       end
-
     end
 
+    class ClearHelpersTest < ActiveSupport::TestCase
+      def setup
+        @controller = HelperyTestController.new
+      end
+
+      def test_clears_up_previous_helpers
+        @controller.process(:with_symbol)
+        assert_equal "I respond to bare_a: false", @controller.response_body
+      end
+
+      def test_includes_controller_default_helper
+        @controller.process(:with_block)
+        assert_equal "Hello Default", @controller.response_body
+      end
+    end
   end
 end

actionpack/test/fixtures/helpers/helpery_test_helper.rb

@@ -0,0 +1,5 @@
+module HelperyTestHelper
+  def helpery_test
+    "Default"
+  end
+end