@rehooks/online-status/src/index.js

React hook for subscribing to `online`/`offline` events and the `navigator.onLine` property to see current status

"use strict";
const { useState, useEffect } = require("react");

function getOnlineStatus() {
  return typeof navigator !== "undefined" &&
    typeof navigator.onLine === "boolean"
    ? navigator.onLine
    : true;
}

function useOnlineStatus() {
  const [onlineStatus, setOnlineStatus] = useState(getOnlineStatus());

  const goOnline = () => setOnlineStatus(true);

  const goOffline = () => setOnlineStatus(false);

  useEffect(() => {
    window.addEventListener("online", goOnline);
    window.addEventListener("offline", goOffline);

    return () => {
      window.removeEventListener("online", goOnline);
      window.removeEventListener("offline", goOffline);
    };
  }, []);

  return onlineStatus;
}

module.exports = useOnlineStatus;