What is the purpose of navigation awaiting in Page.command method?

[lsndr]

I'd like to understand why this logic is present here:

ferrum/lib/ferrum/page.rb

Lines 344 to 353 in 5271866

	if wait.positive?
	# Wait a bit after command and check if iteration has
	# changed which means there was some network event for
	# the main frame and it started to load new content.
	@event.wait(wait)
	if iteration != @event.iteration
	set = @event.wait(timeout)
	raise TimeoutError unless set
	end
	end

I see that wait param passed in go_to method and some methods related to mouse events.

So basically it means if I click on element and navigation happens after down event, the click will fail if navigation doesn't finish within timeout despite the click was successful and led to navigation.

Shouldn't be this "wait for navigation" logic controlled by client and not included in mouse class?

[route]

Please consider Discussion for all kind of questions, issues should not be used like that

[route]

There's a global @event https://ruby-concurrency.github.io/concurrent-ruby/1.1.5/Concurrent/Event.html set to coordinate threads.
Whenever you click a button, it doesn't mean that the page is reloaded for example, so we must wait a bit and see if there were events in the background that kicked the page for reloading, if there were some then we block on @event as it will be released when the page fully loads. It might also not happen and then @event.iteration wouldn't change, so we proceed and return from the method call.

[lsndr]

But why do I need to wait for reloading every time I click a button? And why presence of this reloading should anyhow affect result of executed command? If I clicked and it led to reloading, which took too much time it doesn't mean that my click was unsuccessful.

[route]

Because in Ferrum unlike other JS libs I try to make things safe for end-user. If you click on a link and page starts to load something we must wait until the page is ready to play with. if you click on the link and we return ASAP you'll start playing with the page that in the process of loading content. The wait is very little though, just to see if the were some network events we are interested in.

[route]

For your question about click the wait is 0.1 if during this period @event.iteration hasn't changed we simply return, if it changed we block until the page is ready and lock released.