diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index 038beea32e..e1812a5c89 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -126,7 +126,7 @@ module ActionController
     # ==== Returns
     # * <tt>string</tt>
     def self.controller_name
-      @controller_name ||= name.demodulize.delete_suffix("Controller").underscore
+      @controller_name ||= (name.demodulize.delete_suffix("Controller").underscore unless anonymous?)
     end
 
     def self.make_response!(request)
diff --git a/actionview/lib/action_view/test_case.rb b/actionview/lib/action_view/test_case.rb
index 9f1b36174a..3aa6af0893 100644
--- a/actionview/lib/action_view/test_case.rb
+++ b/actionview/lib/action_view/test_case.rb
@@ -16,11 +16,12 @@ module ActionView
       attr_accessor :request, :response, :params
 
       class << self
-        attr_writer :controller_path
+        # Overrides AbstractController::Base#controller_path
+        attr_accessor :controller_path
       end
 
       def controller_path=(path)
-        self.class.controller_path = (path)
+        self.class.controller_path = path
       end
 
       def initialize
@@ -101,7 +102,7 @@ module ActionView
       end
 
       def setup_with_controller
-        @controller = ActionView::TestCase::TestController.new
+        @controller = Class.new(ActionView::TestCase::TestController).new
         @request = @controller.request
         @view_flow = ActionView::OutputFlow.new
         # empty string ensures buffer has UTF-8 encoding as
diff --git a/actionview/test/template/test_case_test.rb b/actionview/test/template/test_case_test.rb
index bf93259305..55e89cd3f5 100644
--- a/actionview/test/template/test_case_test.rb
+++ b/actionview/test/template/test_case_test.rb
@@ -156,6 +156,13 @@ module ActionView
 
       assert_equal "controller_helper_method", some_method
     end
+
+    class AnotherTestClass < ActionView::TestCase
+      test "doesn't use controller helpers from other tests" do
+        assert_not_respond_to view, :render_from_helper
+        assert_not_includes @controller._helpers.instance_methods, :render_from_helper
+      end
+    end
   end
 
   class ViewAssignsTest < ActionView::TestCase