Rails Capybara chromedriver setup for testing downloads

capybara_chrome_download.rb

# in rails_helper.rb

driver = if ENV['CHROME_DEBUG'] == 'true'
           Capybara.register_driver :chrome do |app|
             Capybara::Selenium::Driver.new(app, browser: :chrome)
           end
           :chrome
         else
           Capybara.register_driver :headless_chrome do |app|
             browser_options = ::Selenium::WebDriver::Chrome::Options.new
             browser_options.add_argument('headless')
             browser_options.add_argument('disable-gpu')
             browser_options.add_argument('window-size=1400,1200')
             browser_options.add_preference('download.default_directory', Rails.root.join('tmp/downloads'))

             Capybara::Selenium::Driver.new(app, browser: :chrome, options: browser_options)
           end
           :headless_chrome
         end

Capybara.javascript_driver = driver
Capybara.default_driver = driver
Capybara.server = :puma, { Silent: true }
Capybara.raise_server_errors = true
Capybara.server_errors << Exception

# spec/support/helpers/download_helper.rb

module DownloadHelpers
  TIMEOUT = 10
  PATH = Rails.root.join('tmp/downloads')

  def downloads
    Dir[PATH.join('*')]
  end

  def last_download
    downloads.last
  end

  def last_download_contents
    wait_for_download
    File.read(last_download)
  end

  def clear_downloads
    FileUtils.rm_f(downloads)
  end
  
  private 
  
  def wait_for_download
    Timeout.timeout(TIMEOUT) do
      sleep 0.1 until downloaded?
    end
  end

  def downloaded?
    !downloading? && downloads.any?
  end

  def downloading?
    downloads.grep(/\.crdownload$/).any?
  end
end