NEW 296048
animation-name assigned by ::part() cannot find animation defined in shadow tree 
https://bugs.webkit.org/show_bug.cgi?id=296048
Summary animation-name assigned by ::part() cannot find animation defined in shadow tree
Haoyang Wang
Reported 2025-07-16 03:40:38 PDT
Created attachment 476040 [details] chromium behavior ```html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Lynx for web</title> <meta content="yes" name="apple-mobile-web-app-capable"> <meta content="default" name="apple-mobile-web-app-status-bar-style"> <meta content="telephone=no" name="format-detection"> <meta content="portrait" name="screen-orientation"> <meta content="width=device-width,initial-scale=1.0,maximum-scale=1.0,user-scalable=no" name="viewport" > <meta content="portrait" name="x5-orientation" /> </head> <body> <style> #shadow::part(target) { height: 300px; width: 300px; animation: ani 1s infinite; } </style> <div style="height:600px; width:300px;" id="shadow"> <template shadowrootmode="open" > <style> @keyframes ani { 0% { background-color: red; } 50% { background-color: blue; } 100% { background-color: green; } } </style> <div part="target"></div> </template> </div> </body> </html> ```
Attachments
chromium behavior (187.77 KB, image/png)
2025-07-16 03:40 PDT, Haoyang Wang 		no flags
Details
firefox behavior (22.46 KB, image/png)
2025-07-16 03:41 PDT, Haoyang Wang 		no flags
Details
wpe (safari 26) behavior (59.46 KB, image/png)
2025-07-16 03:43 PDT, Haoyang Wang 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Haoyang Wang
Comment 1 2025-07-16 03:41:59 PDT
Created attachment 476041 [details] firefox behavior
Haoyang Wang
Comment 2 2025-07-16 03:43:37 PDT
Created attachment 476042 [details] wpe (safari 26) behavior
Radar WebKit Bug Importer
Comment 3 2025-07-23 03:41:12 PDT
<rdar://problem/156484228>
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