import { PerformanceObserver } from "perf_hooks"; declare global { // eslint-disable-next-line no-var var perfObserver: PerformanceObserver | undefined; } export const perfObserver = globalThis.perfObserver || new PerformanceObserver((items) => { items.getEntries().forEach((entry) => { console.log(entry); // fake call to our custom logging solution }); }); if (process.env.NODE_ENV !== "production") { globalThis.perfObserver = perfObserver; } export default perfObserver;