Decouple Timer class to module.

public/js/Timer.js

@@ -0,0 +1,29 @@
+export default class Timer {
+    constructor(deltaTime) {
+        let accumulatedTime = 0;
+        let lastTime = 0;
+
+        this.updateProxy = (time) => {
+            accumulatedTime += (time - lastTime) / 1000;
+
+            while (accumulatedTime > deltaTime) {
+                this.update(deltaTime);
+                accumulatedTime -= deltaTime;
+            }
+
+            lastTime = time;
+
+            this.draw();
+
+            this.enqueue();
+        };
+    }
+
+    enqueue() {
+        requestAnimationFrame(this.updateProxy);
+    }
+
+    start() {
+        this.enqueue();
+    }
+}

public/js/main.js

@@ -1,5 +1,6 @@
 import Compositor from './Compositor.js';
 import Entity from './Entity.js';
+import Timer from './Timer.js';
 import {createMario} from './entities.js';
 import {loadLevel} from './loaders.js';
 import {loadMarioSprite, loadBackgroundSprites} from './sprites.js';
@@ -9,37 +10,6 @@ const canvas = document.getElementById('screen');
 const context = canvas.getContext('2d');
 
 
-class Timer {
-    constructor(deltaTime) {
-        let accumulatedTime = 0;
-        let lastTime = 0;
-
-        this.updateProxy = (time) => {
-            accumulatedTime += (time - lastTime) / 1000;
-
-            while (accumulatedTime > deltaTime) {
-                this.update(deltaTime);
-                accumulatedTime -= deltaTime;
-            }
-
-            lastTime = time;
-
-            this.draw();
-
-            this.enqueue();
-        };
-    }
-
-    enqueue() {
-        requestAnimationFrame(this.updateProxy);
-    }
-
-    start() {
-        this.enqueue();
-    }
-}
-
-
 Promise.all([
     createMario(),
     loadBackgroundSprites(),