Control the speed of Capybara Selenium from the cucumber

cucumber_step_that_needs_to_run_slowly.rv

When /^I drag a tree node somewhere that results in a lot of ajax calls$/ do
  tree_node = page.find('#tree_node_1')
  drop_spot = page.find('#drop_spot')
  
  delay_capybara do
    tree_node.drag_to(drop_spot)
  end
end

throttle_capybara_selenium.rb

require 'selenium-webdriver'

# Pute this file in features/support/

# Control the speed af the Capybara Selenium driver.
# you can now do the following to control the speed of 'Cucumber/Capybara/Selenium'
# CAPYBARA_DELAY=slow be cucumber
# CAPYBARA_DELAY=medium be cucumber
# CAPYBARA_DELAY=fast be cucumber
#
# for a fine grained control do this:
# CAPYBARA_DELAY=0.5 be cucumber
# CAPYBARA_DELAY=1 be cucumber

module ::Selenium::WebDriver::Firefox
  class Bridge
    attr_accessor :delay
    DELAY_SPEEDS = {
      :slow   => 0.3,
      :medium => 0.1,
      :fast   => 0.0
    }
    
    def capybara_compute_delay value
      
      value = value.to_s
      
      return value.to_f if value =~ /\A(\d+\.\d+|\d+)\z/
      
      if value =~ /\A\w+\z/ and DELAY_SPEEDS.include? value.to_sym
        return DELAY_SPEEDS[value.to_sym] 
      end
      return 0
    end
    
    def execute(*args)
      result = raw_execute(*args)['value']
      sleep( capybara_compute_delay(delay) ) if delay
      result
    end
  end
end

module CapybaraDelayHelpers
  def capybara_delay_speed= value
    page.driver.browser.send(:bridge).delay = value
  end
  
  def delay_capybara(options = {:speed => :medium}, &code)
    old_capybara_delay_speed = page.driver.browser.send(:bridge).delay
    page.driver.browser.send(:bridge).delay = options[:speed]
    
    yield
    
    page.driver.browser.send(:bridge).delay = old_capybara_delay_speed
  end
end

World(CapybaraDelayHelpers)

Before('@javascript') do
  if ENV.include? 'CAPYBARA_DELAY'
    capybara_delay_speed = ENV['CAPYBARA_DELAY']
  end
end