DEV: resets page tracking state between tests (#7847)

app/assets/javascripts/discourse/initializers/page-tracking.js.es6

@@ -1,6 +1,7 @@
 import { cleanDOM } from "discourse/lib/clean-dom";
 import {
   startPageTracking,
+  resetPageTracking,
   googleTagManagerPageChanged
 } from "discourse/lib/page-tracker";
 import { viewTrackingRequired } from "discourse/lib/ajax";
@@ -49,5 +50,9 @@ export default {
         }
       });
     }
+  },
+
+  teardown() {
+    resetPageTracking();
   }
 };

app/assets/javascripts/discourse/lib/page-tracker.js.es6

@@ -1,6 +1,5 @@
 let _started = false;
-
-const cache = {};
+let cache = {};
 let transitionCount = 0;
 
 export function setTransient(key, data, count) {
@@ -11,6 +10,12 @@ export function getTransient(key) {
   return cache[key];
 }
 
+export function resetPageTracking() {
+  _started = false;
+  transitionCount = 0;
+  cache = {};
+}
+
 export function startPageTracking(router, appEvents) {
   if (_started) {
     return;