'use strict'; const common = require('../common'); const assert = require('assert'); const util = require('util'); const { performance, PerformanceObserver } = require('perf_hooks'); const perfObserver = new PerformanceObserver(common.mustCall((items) => { const entries = items.getEntries(); assert.ok(entries.length === 1); for (const entry of entries) { assert.ok(util.inspect(entry).includes('this is detail')); } })); perfObserver.observe({ entryTypes: ['measure'] }); performance.measure('sample', { detail: 'this is detail', });