Capybara JavaScript Helpers

capybara_javascript_helpers.rb

# Example:
#
# it "should alert me" do
#   stub_browser_alert
#
#   visit "/"
#
#   wait_until { browser_alert_messages.count > 0 }
#
#   browser_alert_messages.last.should eq("Hello World!")
# end

module CapybaraJavaScriptHelpers
  include Capybara::DSL

  def stub_browser_alert
    page.execute_script(%{
      window.Capybara || (window.Capybara = {});
      window.Capybara.alertMessages = [];
      window.alert = function(message) { 
        window.Capybara.alertMessages.push(message);
      }
    })
  end

  def browser_alert_messages
    page.evaluate_script("window.Capybara.alertMessages")
  end
end