[wp-trac] [WordPress Trac] #58472: Emoji loader script causes ~100ms long task

[WordPress Trac]

#58472: Emoji loader script causes ~100ms long task
--------------------------+--------------------------------------
 Reporter:  westonruter   |       Owner:  westonruter
     Type:  defect (bug)  |      Status:  accepted
 Priority:  high          |   Milestone:  6.3
Component:  Emoji         |     Version:  4.2
 Severity:  normal        |  Resolution:
 Keywords:  has-patch     |     Focuses:  javascript, performance
--------------------------+--------------------------------------

Comment (by westonruter):

 For discussion on whether emoji-loader can go ahead and leave behind IE
 compatibility (which is already deprecated) by leveraging ES6+ syntax
 (specifically async functions), see
 [https://wordpress.slack.com/archives/C02RQBWTW/p1686243321666769 thread
 in #core Slack]. Original thread message:

 > I'm working on enhancing emoji-loader.js to improve performance by
 eliminating a long task that blocks the main thread (#58472). To do this,
 it really means abandoning compatibility with IE11. I know that WP 5.8 had
 a [https://make.wordpress.org/core/2021/04/22/ie-11-support-phase-out-
 plan/ IE 11 Support Phase Out Plan] and that IE is no longer among the
 [https://make.wordpress.org/core/handbook/best-practices/browser-support/
 supported browsers] (indeed, ''all'' versions of IE sum up to only 0.47%
 usage currently). However, my understanding has been that this policy
 ''primarily'' applied to the admin/editor context, and that the frontend
 was not going to jump toward removing IE11 compat. (Granted skip-link-
 focus-fix was just removed #54421.) Do we have the freedom now to
 disregard IE11 compat for frontend features where relevant? In the case of
 emoji-loader, lack of IE11 support would mean users may have broken emoji
 (so likely not a catastrophe, and the least of their problems browsing the
 web today). Thoughts?

 Current concluding remarks in the thread is that a syntax error in the
 emoji-loader script would have the same effect as if the site owner turned
 off emoji-loader entirely (which sites do, as per #35498). So there would
 be a graceful fallback to rendering whatever emoji the platform supports.
 Other scripts on the page would not be impacted. The exception to this is
 if the user has script debugging enabled in which case a dialog would
 appear asking if the user wants to continue running scripts on the page.
 But non-developer users are extremely unlikely to have script debugging
 enabled. For site owners who do, they can just turn off emoji-loader (e.g.
 with the [https://wordpress.org/plugins/disable-emojis/ disable-emojis
 plugin]).

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/58472#comment:17>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform