• fn {Function}

    This property is an extension by Node.js. It is not available in Web browsers.

    Wraps a function within a new function that measures the running time of the wrapped function. A PerformanceObserver must be subscribed to the 'function' event type in order for the timing details to be accessed.

    1. const {
    2.   performance,
    3.   PerformanceObserver
    4. } = require('perf_hooks');
    6. function someFunction() {
    7.   console.log('hello world');
    8. }
    10. const wrapped = performance.timerify(someFunction);
    12. const obs = new PerformanceObserver((list) => {
    13.   console.log(list.getEntries()[0].duration);
    14.   obs.disconnect();
    15. });
    16. obs.observe({ entryTypes: ['function'] });
    18. // A performance timeline entry will be created
    19. wrapped();