How I want these doubles to work

buttheydont.rb

class Foo
  attr_reader :stuff

  def initialize(stuff)
    @stuff = stuff
  end

  def bar
    sock = TCPSocket.new('127.0.0.1', 1337)
    stuff.each do |thing|
      sock.puts thing
      sock.close
    end
  end
end

describe Foo do
  it "will send out a line for each thing" do
    sock = double()
    sock.should_receive(:puts).at_least(:once) do |msg|
      msg.should eq "woo"
    end
    TCPSocket.stub(:new).and_return sock
    
    foo = Foo.new(['woo'])
    foo.bar
  end
  it "doesn't open and close sockets all willy-nilly" do
    sock = double()
    sock.should_receive(:close).once

    foo = Foo.new(['woo', 'yeah', 'party'])
    foo.bar
  end
end

=> Oh no failzor!