> I think @dcherman was pointing out that this is becoming a no-op

Yes... so concern here is that if animation is triggered when document is hidden, animations would never happen, right?

If so, we could workaround that like we do <a href="https://github.com/jquery/jquery/blob/master/src/manipulation.js#L78">here</a> - if animation is scheduled when document is hidden, make a note in the jQuery `_data` object about it, if it scheduled again when document is hidden - do the nop, when (if) document becomes visible again - trigger that first animation on the element(s). But it would require more size for that and i wonder if that really a real world problem, it might be, but i'm not sure - like when some ajax request is finished, when document is hidden, it would not trigger animation to show some box with new info?

Or the concern here that paused animation would not reach it's final state after tabs switching?