Restart and retry when Poltergeist fails randomly.

capybara.rb

# Borrowed from https://github.com/y310/rspec-retry/blob/master/lib/rspec/retry.rb
# Drop this script into spec/support
# To test snippet just set timeout to 1

RSpec.configure do |config|

  Capybara.javascript_driver = :poltergeist

  Capybara.register_driver(:poltergeist) do |app|
    Capybara::Poltergeist::Driver.new app,
      js_errors: true, # optional, i prefer to catch js stuff
      timeout: 180,    # ensure you tweak timeout first !!
      phantomjs_logger: Puma::NullIO.new, # for puma
      logger: nil,
      phantomjs_options:
      [
        '--load-images=no',
        '--ignore-ssl-errors=yes' # only setting this can do the trick sometimes
      ]
  end

  config.around(:each, type: :feature) do |example|
    current_example = RSpec.current_example
    2.times do |index|
      current_example.instance_variable_set('@exception', nil)
      instance_variable_set('@__memoized', nil) # clear let variables
      example.run
      break unless current_example.exception.is_a?(Capybara::Poltergeist::TimeoutError)
      restart_message_for current_example if index == 1
      restart_phantomjs
    end
  end

  def restart_message_for(example)
    msg  = "\n#{example.exception} - restart and retry..\n"
    msg += "    # #{example.location}\n"
    $stdout.puts msg.yellow
  end

  def restart_phantomjs
    Capybara.send('session_pool').each do |_, session|
      next unless session.driver.is_a?(Capybara::Poltergeist::Driver)
      session.driver.restart
    end
  end
end

This code has resolved several months of pain. THANK YOU!

Also, note that instance_variable_set('@__memoized', nil) should be replaced with __init_memoized in rspec 3.3+

Also, occasionally Poltergeist was throwing a different error type on disconnect. We're catching that as well, replacing:

      break unless current_example.exception.is_a?(Capybara::Poltergeist::TimeoutError)
      restart_message_for current_example if index == 1
      restart_phantomjs

with:

      # If Poltergeist state errors happens, restart
      case current_example.exception
      when Capybara::Poltergeist::StatusFailError, Capybara::Poltergeist::TimeoutError
        restart_message_for current_example if index == 1
        restart_phantomjs
      end