require "abstract_unit" class FormBuilderController < ActionController::Base class SpecializedFormBuilder < ActionView::Helpers::FormBuilder ; end default_form_builder SpecializedFormBuilder end class ControllerFormBuilderTest < ActiveSupport::TestCase setup do @controller = FormBuilderController.new end def test_default_form_builder_assigned assert_equal FormBuilderController::SpecializedFormBuilder, @controller.default_form_builder end end