Crash if using scheduleOnRN but not runOnJS

[picked-frames]

Here's the snippet:

useAnimatedReaction(
  () => isDragging.value,
  (curr) => {
    // This line causes the crash
    // scheduleOnRN(() => setPressed(curr ? true : false))

    // This works great
    runOnJS(setPressed)(curr ? true : false)
  }
)

isDragging is a SharedValue<boolean>
setPressed is a React setState function

Not sure if this is worth opening a full issue. I'm using an iPhone 16 Plus Simulator running iOS 18.5 on a M1 Macbook Pro. Here are my dependencies:

"dependencies": {
    "@shopify/react-native-skia": "2.2.12",
    "expo": "54.0.30",
    "expo-linking": "8.0.11",
    "expo-router": "6.0.21",
    "react": "19.1.0",
    "react-dom": "19.1.0",
    "react-native": "0.81.5",
    "react-native-gesture-handler": "2.28.0",
    "react-native-reanimated": "4.1.6",
    "react-native-safe-area-context": "5.6.2",
    "react-native-screens": "4.16.0",
    "react-native-web": "0.21.2",
    "react-native-worklets": "0.5.1"
  },

Love this library! Let me know if I can help or what I might be doing wrong. Thanks.

[vardhanmabbu]

Functions passed to scheduleOnRN must be defined in the RN Runtime scope, i.e. in the component body or the global scope.
The code below won't work because myFunction is defined in the runOnUI callback, which is only executed in the UI Runtime:

import { runOnUI, scheduleOnRN } from 'react-native-worklets';

runOnUI(() => {
  // myFunction is defined on the UI thread 🚨
  const myFunction = () => {
    // ...
  };
  scheduleOnRN(myFunction)(); // 💥
})();

[MatiPl01]

Hey @vardhanmabbu! Thanks for answering this question. Your answer is correct here. I will just add an example showing how to properly schedule function call in RN from a function executed in the UI thread:

useAnimatedReaction(
  () => isDragging.value,
  (curr) => {
    scheduleOnRN(setPressed, curr ? true : false);
  }
);

Basically, the scheduleOnRN must be passed a function declared in the RN runtime. If we want to pass arguments to this call, then we should pass them as subsequent arguments of the scheduleOnRN call like in the example above. The scheduleOnRN signature looks like this:

scheduleOnRN(<function>, <arg1>, <arg2>, ... <argn>)

Where <arg1>, <arg2>, ... <argn> are function arguments (if it takes any)