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AppState Listener Cleanup Bug

Spot the AppState subscription cleanup mistake in a React Native useEffect hook.

Codejavascript

import { useEffect } from 'react';
import { AppState } from 'react-native';

function useAppActive(onActive) {
  useEffect(() => {
    const handler = (state) => {
      if (state === 'active') onActive();
    };
    AppState.addEventListener('change', handler);

    return () => {
      AppState.removeEventListener('change', handler);
    };
  }, [onActive]);
}

What is the bug in this AppState lifecycle code?

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