BUGFIX: clear interval on exit

src/components/Timer.vue

@@ -66,7 +66,6 @@
 </template>
 
 <script>
-var Interval;
 export default {
   name: "Timer",
   props: {
@@ -79,6 +78,7 @@ export default {
       warning: true,
       danger: false,
       wakeLock: null,
+      interval: null,
       sfxTimeout: this.playsound ? new Audio('sfx/timeout.wav') : null,
       sfxWarning: this.playsound ? new Audio('sfx/warning.wav') : null,
       sfxNext: this.playsound ? new Audio('sfx/next.wav') : null,
@@ -86,6 +86,7 @@ export default {
   },
   methods: {
     resetTime: function() {
+      clearInterval(this.interval);
       this.$emit('set-time', 0);
     },
     timeleft: function(){
@@ -128,7 +129,7 @@ export default {
           if(this.playsound) {
             this.sfxTimeout.play();
           }
-          clearInterval(Interval);
+          clearInterval(this.interval);
           break;
       }
     },
@@ -142,8 +143,8 @@ export default {
       this.countDown = this.time;
       this.warning = false;
       this.danger = false;
-      clearInterval(Interval);
-      Interval = setInterval(() => {
+      clearInterval(this.interval);
+      this.interval = setInterval(() => {
         this.timeleft()
       }, 1000);
     },