measuring how long it takes to load dependencies

The following example measures the duration of require() operations to load dependencies:

'use strict';
const {
  performance,
  PerformanceObserver
} = require('perf_hooks');
const mod = require('module');
// Monkey patch the require function
mod.Module.prototype.require =
  performance.timerify(mod.Module.prototype.require);
require = performance.timerify(require);
// Activate the observer
const obs = new PerformanceObserver((list) => {
  const entries = list.getEntries();
  entries.forEach((entry) => {
    console.log(`require('${entry[0]}')`, entry.duration);
  });
  obs.disconnect();
});
obs.observe({ entryTypes: ['function'], buffered: true });
require('some-module');