fix: lazy initialize MixpanelPersistent instance

Author: aljadan

javascript/mixpanel-queue.js

@@ -2,11 +2,18 @@ import {MixpanelPersistent} from "./mixpanel-persistent";
 
 export const MixpanelQueueManager = (() => {
   let _queues = {};
-  const mixpanelPersistent = MixpanelPersistent.getInstance();
+  let mixpanelPersistent;
+
+  const getPersistent = () => {
+    if (!mixpanelPersistent) {
+        mixpanelPersistent = MixpanelPersistent.getInstance();
+    }
+    return mixpanelPersistent;
+  };
 
   const initialize = async (token, type) => {
     if (!_queues[token] || !_queues[token][type]) {
-      const queue = await mixpanelPersistent.loadQueue(token, type);
+      const queue = await getPersistent().loadQueue(token, type);
       _queues[token] = {
         ..._queues[token],
         [type]: queue,
@@ -18,7 +25,7 @@ export const MixpanelQueueManager = (() => {
     if (!_queues[token] || !_queues[token][type]) {
       return;
     }
-    await mixpanelPersistent.saveQueue(token, type, _queues[token][type]);
+    await getPersistent().saveQueue(token, type, _queues[token][type]);
   };
 
   const enqueue = async (token, type, data) => {