watir-webdriver源码阅读

module Watir
class Browser
    def initialize(browser = :firefox, *args)
      case browser
      when Symbol, String
        @driver = Selenium::WebDriver.for browser.to_sym, *args
      when Selenium::WebDriver::Driver
        @driver = browser
      else
        raise ArgumentError, "expected Symbol or Selenium::WebDriver::Driver, got #{browser.class}"
      end
     
      @error_checkers = []
      @current_frame  = nil
      @closed         = false
     
    end
end
end

class << self
      def start(url, browser = :firefox)
        b = new(browser)
        b.goto url
        b
      end
    end

def goto(uri)
      uri = "http://#{uri}" unless uri =~ URI.regexp

      @driver.navigate.to uri
      run_checkers

      url
    end

def run_checkers
      @error_checkers.each { |e| e.call(self) }
    end