const { TraceEvents, trackRequires } = require('perftrace');
const { writeFileSync } = require('fs');
const traceEvents = new TraceEvents();
// Writes the performance traces in the "events.json" file during process exit.
process.on("beforeExit", () => {
  const events = traceEvents.getEvents();
  traceEvents.destroy();
  writeFileSync("events.json", JSON.stringify(events));
});
// Enables tracking require() calls.
trackRequires(true, { trackSource: true });
// The assert module takes milliseconds to load, so it would be distinctly
// visible in the performance trace.
const assert = require('assert');
const { performance } = require("node:perf_hooks");
// This is tracing an async setTimeout event which is interlaced with
// repeating setInterval events.
performance.mark("Timeout mark"); // marks the beginning of the timeout trace
setTimeout(() => {
  performance.measure("Timeout", "Timeout mark"); // marks the ending of the timeout trace
}, 20);
let id = 0;
performance.mark(`Interval mark ${id}`); // marks the beginning of the first interval trace
setInterval(function () {
  performance.measure(`Interval ${id}`, `Interval mark ${id}`); // marks the ending of the current interval trace
  ++id;
  // The intervals should go up to 3 counts only.
  if (id === 3) {
    this.close();
  }
  performance.mark(`Interval mark ${id}`); // marks the beginning of the next interval trace
}, 5);