Get a HAR export of internet activity triggered by a passing a URL to a browser with Ruby and Watir-Webdriver

net-export-with-ruby-and-watir.rb

require 'watir-webdriver'

profile = Selenium::WebDriver::Firefox::Profile.new
profile.add_extension "/your/path/to/Firefox/profile/extensions/firebug@software.joehewitt.com.xpi"
profile.add_extension "/your/path/to/Firefox/profile/extensions/netexport@getfirebug.com.xpi"

profile["extensions.firebug.currentVersion"] = "2.0.14" # Supress "What's new in Firebug" tab from opening.
profile["extensions.firebug.delayLoad"] = false
profile["extensions.firebug.showFirstRunPage"] = false
profile["extensions.firebug.console.enableSites"] = true
profile["extensions.firebug.net.enableSites"] = true
profile["extensions.firebug.script.enableSites"] = true
profile["extensions.firebug.defaultPanelName"] = 'net'
profile["extensions.firebug.allPagesActivation"] = "on"

profile["extensions.firebug.netexport.alwaysEnableAutoExport"] = true
profile["extensions.firebug.netexport.showPreview"] = false
profile["extensions.firebug.netexport.defaultLogDir"] = "/your/preferred/path/for/hars"
profile["extensions.firebug.netexport.autoExportToServer"] = false
profile["extensions.firebug.netexport.sendToConfirmation"] = false
profile["extensions.firebug.netexport.pageLoadedTimeout"] = 2500
profile["extensions.firebug.netexport.Automation"] = true
profile["extensions.firebug.netexport.saveFiles"] = true

b = Watir::Browser.new :firefox, :profile => profile
b.goto "http://your-site.com"
# Do whatever else you need to do.

b.close if b

require 'har'
h = HAR::Archive.from_file("/your/preferred/path/for/hars/yourfile.har")

# Access your archive, a JSON hash of each network call, and its timing
# Example: Search for calls to 'facebook'
h.entries.map{|e| e.request.url if e.request.url.include?("facebook")}.compact
# => ["http://connect.facebook.net/en_US/acbd.js", "https://www.facebook.com/tr/?id=123456&ev=PixelInitialized&dl=http%3A%2F%2Fwww.yoursite.com%2F&rl=&if=false&ts=123456", "http://www.facebook.com/fr/u.php?p=123456&m=332211", "https://www.facebook.com/fr/u.php?p=123456&m=112233", "http://match.adsrvr.org/track/cmf/generic?ttd_pid=facebook"]