port_checker_spec.rb

  describe PortChecker do
    around :each do |block|
      EventMachine.run(&block)
    end

    it 'succeeds immediately if port is open' do
      success = false
      failure = false

      EventMachine.start_server('localhost', 11111)

      EventMachine.add_timer 0.05 do
        success.should be_true
        failure.should be_false
        EventMachine.stop
      end

      PortChecker.new('localhost', 11111, 0.1, 1)
        .callback {
          success = true
        }.errback {
          failure = true
        }
    end

    it 'waits until the port is open' do
      success = false
      failure = false

      EventMachine.add_timer 0.05 do
        success.should be_false
        failure.should be_false
        EventMachine.start_server('localhost', 11111)
      end

      EventMachine.add_timer 0.25 do
        success.should be_true
        failure.should be_false
        EventMachine.stop
      end

      PortChecker.new('localhost', 11111, 0.1, 1)
        .callback {
          success = true
        }.errback {
          failure = true
        }
    end

    it 'fails when the port is not open within specified timeout interval' do
      success = false
      failure = false

      EventMachine.add_timer 0.25 do
        success.should be_false
        failure.should be_false
      end

      EventMachine.add_timer 0.6 do
        success.should be_false
        failure.should be_true
        EventMachine.stop
      end

      PortChecker.new('localhost', 11111, 0.1, 0.5)
        .callback {
          success = true
        }.errback {
          failure = true
        }
    end
  end