Bug with animatedIndex prop of Backdrop Component in BottomSheetModal

Bug: animatedIndex prop of Backdrop Component in BottomSheetModal doesn’t work as expected

I think the animatedIndex in BottomSheetModal has not correct type and can’t be animated using interpolate function of reanimated library. If I use BottomSheet instead of BottomSheetModal, it works properly, but in BottomSheetModal, animatedIndex doesn’t work properly

Environment info

Library	Version
@gorhom/bottom-sheet	2.3
react-native	0.63.4
react-native-reanimated	1.9.0
react-native-gesture-handler	1.10.3

Steps To Reproduce

1. Create a BottomSheetModal
2. Provide Custom Backdrop Component
3. Try to animate the Backdrop using animatedIndex

Describe what you expected to happen:

1. I expected animatedIndex to be an animated value

[theMasix]

Issue resolved! It was all about snapPoints.

my previous snapPoints was

  const snapPoints = useMemo(() => [0, contentHeight], [contentHeight]);

and I updated them to

  const snapPoints = useMemo(() => [contentHeight], [contentHeight]);

Now the animatedIndex and animations works as expected. I don’t know why my previous snapPoints worked with BottomSheet properly. It would be great if you can provide more information about snapPoints and how they works in the doc. So no one will have any issue same as mine.

@gorhom

[b0n1q]

described here: https://github.com/gorhom/react-native-bottom-sheet/issues/846