require 'test/unit' class TestClone < Test::Unit::TestCase module M001; end module M002; end module M003; include M002; end module M002; include M001; end module M003; include M002; end def test_clone foo = Object.new def foo.test "test" end bar = foo.clone def bar.test2 "test2" end assert_equal("test2", bar.test2) assert_equal("test", bar.test) assert_equal("test", foo.test) assert_raises(NoMethodError) {foo.test2} assert_equal([M003, M002, M001], M003.ancestors) end end