test_weakref.rb

require 'test/unit'
require 'weakref'

# Result: <WeakRef::RefError> exception expected but none was thrown - why?

class TC_Stdlib_WeakRef < Test::Unit::TestCase
  test "weakref raises an error on garbage collected ref" do
    str = 'hello'
    ref = WeakRef.new(str)
    str = nil
    GC.start
    assert_raise(WeakRef::RefError){ ref.to_s }
  end
end