How to unit test for exception in threads

I need to unit test that an exception in raised in code like:

开发者_如何学Cdef test
  assert_raise Timeout::Error do
    Thread.new {
      raise  Timeout::Error
    }
  end
end

How to get this working?

---

in the assert_raise block:

t = Thread.new { raise Timeout::Error }
t.join