Synchronous 'DOMNodeInserted' DOM Mutation Event is deprecated

[cancan101]

Seeing this warning from Chrome:

Listener added for a synchronous 'DOMNodeInserted' DOM Mutation Event. This event type is deprecated (https://w3c.github.io/uievents/#legacy-event-types) and work is underway to remove it from this browser. Usage of this event listener will cause performance issues today, and represents a risk of future incompatibility. Consider using MutationObserver instead.

which I think is coming from this line:

gmail.js/src/gmail.js

Line 2678 in 080b394

$(window.document).on("DOMNodeInserted", function(e) {

there was some discussion about the implementation:

• jQuery errors due to mutation observers and nested jQuery.find() #560
• Observer on the side panel? #636 (comment)

but it may be the case that this needs to be changed sooner than later.

[josteink]

Thats probably very likely yes. Thanks for the heads up.

I'm going to assume we can fix this somehow by making a non-synchronous handler instead (from the browsers POV). For my extension that's probably fine. I'm going to assume most people using our view_email events (and friends) don't have a hard-dependency on it being synchronous either.

Does anyone have time to look into what the alternate implementation looks like?

[Kravimir]

The alternative is to use a MutationObserver.

[cancan101]

See https://developer.chrome.com/blog/mutation-events-deprecation/#use-mutationobserver-instead for migration suggestion.

I would think these might be able to be merged unless there is a reason one uses body and one uses document: https://github.com/KartikTalwar/gmail.js/blob/080b39455acba8620efbb50a7caf984af8fbdc86/src/gmail.js#L2678C33-L2702