Method: Capybara::Node::Base#synchronize

Defined in:
lib/capybara/node/base.rb

#synchronize(seconds = nil, errors: nil) ⇒ Object

This method is Capybara's primary defence against asynchronicity problems. It works by attempting to run a given block of code until it succeeds. The exact behaviour of this method depends on a number of factors. Basically there are certain exceptions which, when raised from the block, instead of bubbling up, are caught, and the block is re-run.

Certain drivers, such as RackTest, have no support for asynchronous processes, these drivers run the block, and any error raised bubbles up immediately. This allows faster turn around in the case where an expectation fails.

Only exceptions that are ElementNotFound or any subclass thereof cause the block to be rerun. Drivers may specify additional exceptions which also cause reruns. This usually occurs when a node is manipulated which no longer exists on the page. For example, the Selenium driver specifies `Selenium::WebDriver::Error::ObsoleteElementError`.

As long as any of these exceptions are thrown, the block is re-run, until a certain amount of time passes. The amount of time defaults to Capybara.default_max_wait_time and can be overridden through the `seconds` argument. This time is compared with the system time to see how much time has passed. On rubies/platforms which don't support access to a monotonic process clock if the return value of `Time.now` is stubbed out, Capybara will raise `Capybara::FrozenInTime`.

Parameters:

  • seconds (Integer) (defaults to: nil)

    (current sessions default_max_wait_time) Maximum number of seconds to retry this block

  • errors (Array<Exception>)

    (driver.invalid_element_errors + [Capybara::ElementNotFound]) exception types that cause the block to be rerun

Returns:

  • (Object)

    The result of the given block

Raises:



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# File 'lib/capybara/node/base.rb', line 76

def synchronize(seconds = nil, errors: nil)
  return yield if session.synchronized

  seconds = session_options.default_max_wait_time if seconds.nil?
  session.synchronized = true
  timer = Capybara::Helpers.timer(expire_in: seconds)
  begin
    yield
  rescue StandardError => err
    session.raise_server_error!
    raise err unless driver.wait? && catch_error?(err, errors)
    raise err if timer.expired?

    sleep(0.05)
    reload if session_options.automatic_reload
    retry
  ensure
    session.synchronized = false
  end
end