Explicitly set _initializationDeferred to false upon enabling tracking (when a user explicitly opts into analytics), move deferInitialization check where this._storageSuffix is actually defined (in the try block)

* set initializedDeferred = false in enableTracking()
* make sure this._storageSuffix is defined when cookies are being checked
* Added tests for sending events after tracking is enabled
* Added assertions to ensure that each test starts with a clean slate (no unsentEvents) before enabling tracking

Author: sputh

src/amplitude-client.js

@@ -75,16 +75,16 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
     return;
   }
 
-  var hasExistingCookie = !!this.cookieStorage.get(this.options.cookieName + this._storageSuffix);
-  if (opt_config && opt_config.deferInitialization && !hasExistingCookie) {
-    this._deferInitialization(apiKey, opt_userId, opt_config, opt_callback);
-    return;
-  }
-
   try {
     this.options.apiKey = apiKey;
     this._storageSuffix = '_' + apiKey + this._legacyStorageSuffix;
 
+    var hasExistingCookie = !!this.cookieStorage.get(this.options.cookieName + this._storageSuffix);
+    if (opt_config && opt_config.deferInitialization && !hasExistingCookie) {
+      this._deferInitialization(apiKey, opt_userId, opt_config, opt_callback);
+      return;
+    }
+
     _parseConfig(this.options, opt_config);
 
     if (type(this.options.logLevel) === 'string') {
@@ -1619,10 +1619,12 @@ AmplitudeClient.prototype._deferInitialization = function _deferInitialization(a
 /**
  * Enable tracking via logging events and dropping a cookie
  * Intended to be used with the deferInitialization configuration flag
+ * This will drop a cookie and reset initialization deferred
  * @public
  */
 AmplitudeClient.prototype.enableTracking = function enableTracking() {
   // This will call init (which drops the cookie) and will run any pending tasks
+  this._initializationDeferred = false;
   _saveCookieData(this);
   this.runQueuedFunctions();
 };

test/amplitude-client.js

@@ -3369,7 +3369,7 @@ describe('setVersionName', function() {
       });
     });
 
-    describe('upon to opting into analytics', function () {
+    describe('upon opting into analytics', function () {
       it('should drop a cookie', function () {
         amplitude.enableTracking();
         var cookieData = cookie.get(amplitude.options.cookieName + '_' + apiKey);
@@ -3380,12 +3380,28 @@ describe('setVersionName', function() {
         amplitude.logEvent('Event Type 1');
         amplitude.logEvent('Event Type 2');
         amplitude.logEventWithTimestamp('test', null, 2000, null);
+        assert.lengthOf(amplitude._unsentEvents, 0, 'should not have any pending events to be sent');
         amplitude.enableTracking();
 
+        assert.lengthOf(server.requests, 1, 'should have sent a request to Amplitude');
         var events = JSON.parse(queryString.parse(server.requests[0].requestBody).e);
         assert.lengthOf(events, 1, 'should have sent a request to Amplitude');
         assert.lengthOf(amplitude._unsentEvents, 3, 'should have saved the remaining events')
       });
+      it('should send new events', function () {
+        assert.lengthOf(amplitude._unsentEvents, 0, 'should start with no pending events to be sent');
+        amplitude.identify(new Identify().set('prop1', 'value1'));
+        amplitude.logEvent('Event Type 1');
+        amplitude.logEvent('Event Type 2');
+        amplitude.logEventWithTimestamp('test', null, 2000, null);
+        assert.lengthOf(amplitude._unsentEvents, 0, 'should not have any pending events to be sent');
+
+        amplitude.enableTracking();
+        assert.lengthOf(amplitude._unsentEvents, 3, 'should have saved the remaining events')
+
+        amplitude.logEvent('Event Type 3');
+        assert.lengthOf(amplitude._unsentEvents, 4, 'should save the new events')
+      });
       it('should not continue to deferInitialization if an amplitude cookie exists', function () {
         amplitude.enableTracking();
         amplitude.init(apiKey, null, { cookieExpiration: 365, deferInitialization: true });