Animated.event with useNativeDriver disregards interpolations/etc when re-rendering

The initial interpolated animation value of an Animated.event with useNativeDriver is calculated correctly, but once it gets re-rendered then the interpolation is ignored. But when it re-renders again, then the interpolated value is again correct. So: 1st render: Correct value 2nd render: Incorrect (0) 3rd render: Correct. 4th…*: Correct.

This also applies to Animated.add nodes as well. I simulate re-rendering with a timer that calls this.forceUpdate(). Here is a boiled-down code sample. Here is a video of the code sample running (RNPlay won’t work for this)

I don’t know how to work around this. Using setValue in componentWillMount doesn’t make a difference.

Additional Information

• React Native version: 0.41.2
• Platform: iOS
• Operating System: macOS 10.12.3

[janicduplessis]

Thanks for trying that out, I’ll see if I can figure out the cause with @scarlac repro.

[willdawsonme]

No luck here, but here’s a repro! https://snack.expo.io/SyQd4Bkal It doesn’t actually need interpolated values, just an Animated.Value.

In the repro, the ScrollView starts at an arbitrary x offset. After 3 seconds, the Header is re-rendered with a state update, which causes it to ignore the animated translateX value on the header until you re-scroll the main view.

Let me know if you need any more info! Thanks