How to test a code performance in Node.js?

const Meter = require('performancemeter');

Meter.measure('Uncached', function() {
    fn({ success: true });
}, function() {
    function fn(obj){obj.success;}
});

Meter.measure('Cached', function() {
    fn(success);
}, function() {
    var success = { success: true };
    function fn(obj){obj.success;}
});

const Meter = require('performancemeter');

Meter.measure('Uncached', function() {
    fn({ success: INDEX % 2 === 0 });
}, function() {
    function fn(obj){obj.success;}
});

Meter.measure('Cached with assignment', function() {
    success.success = INDEX % 2 === 0;
    fn(success);
}, function() {
    var success = { success: true };
    function fn(obj){obj.success;}
});

const Meter = require('performancemeter');

Meter.measure('delete', function() {
    var obj = { success: true };
    delete obj.success;
    JSON.stringify(obj);
});

Meter.measure('undefined', function() {
    var obj = { success: true };
    obj.success = undefined;
    JSON.stringify(obj);
});

Meter.mode('low');

const Meter = require('performancemeter');

Meter.measure('Uncached', function() {
    fn(new Date());
}, function() {
    function fn(dt) {dt;}
});

Meter.measure('Cached', function() {
    fn(current);
}, function() {
    var current = new Date();
    function fn(dt) {dt;}
});

Meter.measure('Partially cached', function() {
    if (INDEX % 5 === 0)
        current = new Date();
    fn(current);
}, function() {
    var current = new Date();
    function fn(dt) {dt;}
});