gistfile1.rb

require 'ffi-tk'
require 'bacon'

Tk.init

b = lambda {
  describe 'Tk.root.tk_inactive' do
    it 'resets' do
      inactive = Tk.root.tk_inactive
      inactive.should > 0
      Tk.root.tk_inactive('reset'); sleep 0.5
      Tk.root.tk_inactive.should < inactive
    end
  end
  Bacon.handle_summary
  Tk.exit
}

Tk::After.ms(2000, &b)
Tk.mainloop

__END__
Bacon::Error: 3210.<(2709) failed
        tk_perlin_.rb:13:in `block (3 levels) in <main>': Tk.root.tk_inactive - resets