Use Unix timestamp instead of incremented int

Author: knagurski

lib/TimerFormatter.js

@@ -16,6 +16,7 @@ export function extractMilliseconds(time) {
 }
 
 export function format(time) {
+  time = Math.round(time / 10);
   const minutes = (extractMinutes(time) + "").padStart(2, "0");
   const seconds = (extractSeconds(time) + "").padStart(2, "0");
   const milliseconds = (extractMilliseconds(time) + "").padStart(2, "0");

lib/stopwatch.js

@@ -2,33 +2,34 @@ import { format } from "./TimerFormatter.js";
 
 class Stopwatch {
   constructor() {
-    this.precision = 10;
-
     this.timeElapsed = 0;
-    this.interval = null;
+    this.startTime = null;
 
     this.laps = [];
   }
 
   get isCounting() {
-    return !!this.interval;
+    return !!this.startTime;
   }
 
   get elapsed() {
+    if (this.isCounting) {
+      this.timeElapsed += Date.now() - this.startTime;
+      this.startTime = Date.now();
+    }
+
     return format(this.timeElapsed);
   }
 
   start() {
-    if (!this.interval) {
-      this.interval = setInterval(() => {
-        this.timeElapsed++;
-      }, this.precision);
+    if (!this.isCounting) {
+      this.startTime = Date.now();
     }
   }
 
   stop() {
-    clearInterval(this.interval);
-    this.interval = null;
+    this.timeElapsed += Date.now() - this.startTime;
+    this.startTime = null;
   }
 
   reset() {