require 'test/unit' require File.dirname(__FILE__) + '/../../lib/core_ext/object_and_class' class A; end class B < A; end class C < B; end class D < A; end class ClassExtTest < Test::Unit::TestCase def test_methods assert defined?(B) assert defined?(C) assert defined?(D) A.remove_subclasses assert !defined?(B) assert !defined?(C) assert !defined?(D) end end