chrome-extension_spec.rb

require 'capybara'

# $ xvfb-run rspec -f documentation chrome-extension_spec.rb
#
# ./myext -- Directory containing the unpacked extension

class ChromeBrowser
  include Capybara::DSL
  
  def initialize(chrome_flags = {})
    Capybara.register_driver :selenium_chrome do |app|
      chrome_opts = chrome_flags.map do |arg, value|
        case value 
        when true 
          "--#{arg}"
        when false
          nil
        else
          "--#{arg}=#{value}"
        end
      end.compact
      Capybara::Selenium::Driver.new(app, browser: :chrome, switches: chrome_opts)
    end
    Capybara.current_driver = :selenium_chrome
  end
end

describe "Chrome with extension <myext> installed" do
  let(:browser) do
    ChromeBrowser.new("user-data-dir" => ".myext-profile", "load-extension" => "myext")
  end

  describe "visiting page" do
    before(:all) { browser.visit("http://someurl") }
    
    it "adds a link (example)" do
      expect(browser.find("a#link_added_my_content_script")).to be_truthy
    end
  end
end