fix: prevent JS error when calling analytics.user() (#164)

Author: Adam Stankiewicz

.env.development

@@ -14,7 +14,7 @@ STUDIO_BASE_URL=http://localhost:18010
 MARKETING_SITE_BASE_URL=http://localhost:18000
 ORDER_HISTORY_URL=http://localhost:1996/orders
 REFRESH_ACCESS_TOKEN_ENDPOINT=http://localhost:18000/login_refresh
-SEGMENT_KEY=ul
+SEGMENT_KEY=null
 SITE_NAME=Open edX
 USER_INFO_COOKIE_NAME=edx-user-info
 LOGO_URL=https://edx-cdn.org/v3/default/logo.svg

.gitignore

@@ -5,3 +5,4 @@ coverage
 dist
 node_modules
 /docs/api
+.env.private

src/analytics/SegmentAnalyticsService.js

@@ -158,28 +158,17 @@ class SegmentAnalyticsService {
   identifyAnonymousUser(traits) {
     // if we do not have an authenticated user (indicated by being in this method),
     // but we still have a user id associated in segment, reset the local segment state
-    // This has to be wrapped in the document.readyState logic because the analytics.user()
+    // This has to be wrapped in the analytics.ready() callback because the analytics.user()
     // function isn't available until the analytics.js package has finished initializing.
     return new Promise((resolve, reject) => { // eslint-disable-line no-unused-vars
-      if (document.readyState === 'complete') {
+      global.analytics.ready(() => {
         if (global.analytics.user().id()) {
           global.analytics.reset();
         }
         global.analytics.identify(traits);
         this.hasIdentifyBeenCalled = true;
         resolve();
-      } else {
-        document.addEventListener('readystatechange', event => {
-          if (event.target.readyState === 'complete') {
-            if (global.analytics.user().id()) {
-              global.analytics.reset();
-            }
-            global.analytics.identify(traits);
-            this.hasIdentifyBeenCalled = true;
-            resolve();
-          }
-        });
-      }
+      });
     });
   }
 

src/analytics/interface.test.js

@@ -46,6 +46,11 @@ beforeEach(() => {
   window.analytics.page = jest.fn();
   window.analytics.track = jest.fn();
   window.analytics.reset = jest.fn();
+  window.analytics.ready = jest.fn((callback) => {
+    if (callback) {
+      callback();
+    }
+  });
 });
 
 describe('analytics sendTrackingLogEvent', () => {