react-firehooks/lib/internal/useIsMounted.js

Lightweight dependency-free collection of React hooks for Firebase

import { useEffect, useRef } from "react";
/**
 * @internal
 */
export function useIsMounted() {
    const isMounted = useRef(false);
    useEffect(() => {
        isMounted.current = true;
        return () => {
            isMounted.current = false;
        };
    }, []);
    return isMounted;
}