tmarker mark sequence time easily. quick start import {TimeMarker} from 'tmarker'; const marker = new TimeMarker(['a', 'b', 'c'], data => { console.log(data);}); marker.mark('a');setTimeout(() => { marker.mark('b');}, 500);setTimeout(() => { marker.mark('c'); // callback get { b: 507, c: 1003 }}, 1000);