Function handler

hot/dev-server.js:71–77

(event)

	 * @param {CustomEvent<{ currentHash: string }>} event event or hash
	 */
	var handler = function (event) {
		lastHash = typeof event === "string" ? event : event.detail.currentHash;
		if (!upToDate() && module.hot.status() === "idle") {
			log("info", "[HMR] Checking for updates on the server...");
			check();
		}
	};

	if (typeof EventTarget !== "undefined" && hotEmitter instanceof EventTarget) {
		hotEmitter.addEventListener(