GOOS: auction snipper, single message listener

single_message_listener.rb

#
# https://github.com/yevgenko/ruby-auction_sniper/blob/master/spec/fake_auction_server.rb
#
# https://www.safaribooksonline.com/library/view/growing-object-oriented-software/9780321574442/ch11.html
#
class SingleMessageListener
  include RSpec::Matchers

  def initialize
    @messages = SizedQueue.new(1)
  end

  def process_message(message)
    @messages << message
  end

  def has_a_message
    expect(message(timeout: 5)).not_to be_nil
  end

  private

  def message(timeout:)
    message = nil
    Thread.new { message = @messages.pop }.join timeout
    message
  end
end