Function useSyncExternalStore

compat/src/hooks.js:9–42

(subscribe, getSnapshot)

 * @typedef {{ _value: any; _getSnapshot: () => any }} Store
 */
export function useSyncExternalStore(subscribe, getSnapshot) {
	const value = getSnapshot();

	/**
	 * @typedef {{ _instance: Store }} StoreRef
	 * @type {[StoreRef, (store: StoreRef) => void]}
	 */
	const [{ _instance }, forceUpdate] = useState({
		_instance: { _value: value, _getSnapshot: getSnapshot }
	});

	useLayoutEffect(() => {
		_instance._value = value;
		_instance._getSnapshot = getSnapshot;

		if (didSnapshotChange(_instance)) {
			forceUpdate({ _instance });
		}
	}, [subscribe, value, getSnapshot]);

	useEffect(() => {
		if (didSnapshotChange(_instance)) {
			forceUpdate({ _instance });
		}

		return subscribe(() => {
			if (didSnapshotChange(_instance)) {
				forceUpdate({ _instance });
			}
		});
	}, [subscribe]);

	return value;
}

/** @type {(inst: Store) => boolean} */
function didSnapshotChange(inst) {