Elevation and border radius do not work well with opacity from Android 9

The way elevation works is that it creates a border around the element that is then shifted to the bottom. The background color of the element then hides the inside part of the border.

When we apply border radius to the same element, the border gets thicker to accommodate for the increased radius. So far so good.

Unfortunately if we then apply the opacity to the parent, the background color of the element gets semitransparent, making the border visible and creating an ugly effect.

React Native version: 0.57
Expo SDK 32
Android version: 9.0

Steps To Reproduce

Create an element and apply, elevation, border radius and background color. Then apply opacity on its parent.

Describe what you expected to happen:

The border underneath the element should not leak out

Snack, code example, or link to a repository:

https://snack.expo.io/SJDAlu6TV

Commencez par exécuter l’Expo Snack lié avec React Native 0.57, Expo SDK 32 et Android 9, puis reproduisez la combinaison de elevation, border radius, background color et parent opacity. C’est terminé lorsque la bordure d’elevation ne transparaît plus visiblement à travers l’arrière-plan semi-transparent et que le style attendu reste intact.