I'm trying to get the slotted item to fill the parents container in Safari. The following works in Chrome, FF, even Edge-Chromium, but not Safari. I only have ability to modify the content and styles of the slotted item and not the slot's container (i.e i can modify .c-name, but not user-card) https://jsfiddle.net/vhu8x716/
On additional review, it appears the issue is most associated with the 'flex: auto;' defined in the web-component. Changing this to 'flex: 1 1 100%' resolved the issue, but again this requires making changes to third party webcomponents
<rdar://problem/75749136>
Is this bug really dependent on using slot? Or it reproduces anywhere?
No, looks like its an issue with `flex:auto` in general