The spec mentions visibilityState as a replacement. It has a pretty good browser support, but, alas, it starts at IE 10 so we'd need a fallback anyway.

On the other hand, I'd rather avoid us preventing the document.hidden removal because we used it not as a fallback... But if we changed that we'd need to change Core as well (cc @markelog, what do you think?).

Wait, document.hidden is only supported in IE 10+ as well: https://developer.mozilla.org/en-US/docs/Web/API/Document/hidden. Perhaps we should just switch to document.visibilityState everywhere?

We could switch I suppose. Most likely document.hidden will stay around forever. I'll create a ticket in core, Migrate should follow whatever we decide to do but I'll land this in the meantime.

Mm, my understanding that if document is hidden we still use this property, is there intention to replace such logic?

@markelog The issue is document.hidden is deprecated in favor of document.visibilityState and we should avoid deprecated APIs, especially when they have a replacement. Unfortunately, it seems IE doesn't support the new API.

@markelog The issue is document.hidden is deprecated in favor of document.visibilityState and we should avoid deprecated APIs, especially when they have a replacement. Unfortunately, it seems IE doesn't support the new API.

That's not what I meant :).

I am talking about jQuery.fx.interval, with that prism my previous comment should be a bit more clear I suppose :)

Okay, I see your point here – #292 (comment)

I think we might want to show the warning only when this property is set – not on the getter

@markelog That's one solution but a warning for the getter makes sense as well as we don't want people to rely on this value.

We used as a getter, it still has fully legitimated use, but one might argue that should not be changed, that's how I see it.

But of course you can do whatever you want here :)

I'm going to keep the getter in case someone happens to read it in their own code. Our helpful friends at StackOverflow (😭) often seem to think it will fix some problem or another, although most involve assigning some horribly large or small value.

https://stackoverflow.com/search?q=jquery.fx.interval

Our helpful friends at StackOverflow (😭) often seem to think it will fix some problem or another, although most involve assigning some horribly large or small value.

That's an explanation to keep the setter? Well, whatever, forget it, I don't want to argue about it

@markelog not arguing at all, just letting you know that I wanted to keep the getter. This PR will eliminate the false positive for now and we can change core later.

Landed at 758a138