Does useSharedValue() preserve its default value across hot reloads by design?

[rhinck]

Hi everyone 👋

I just wanted to confirm whether this is intended behavior or not.

When I change the initial value of a shared value, the new default doesn’t seem to take effect after saving — it only updates after a full reload (pressing r in Expo CLI).

Example

const top = useSharedValue(600);

If I change that to 650 and save, nothing moves until I manually reload the app (Expo SDK 54).

Question

Is this the expected behavior — for example, that useSharedValue persists its state in memory across hot reloads — or should hot reloads also re-initialize the default value?

Thanks in advance for clarifying! 🙏

[tomekzaw]

@rhinck Thanks for asking! Yes, this is an intended behavior. If you wish to reset the shared value on each hot reload, you might wanna consider resetting the shared value in an effect like this:

useEffect(() => {
  top.value = 600; // reset shared value on hot reload
}, []);

You can also use the same trick to restart an animation on each fast refresh:

useEffect(() => {
  top.value = 600;
  top.value = withTiming(700);
}, []);