add helper method to fetch sessionId

Author: djih

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Unreleased
 
+* Add getSessionId helper method to fetch the current sessionId.
+
 ## 2.7.0 (December 1, 2015)
 
 * If cookies are disabled by user, then fallback to localstorage to save the cookie data.

amplitude.js

@@ -290,6 +290,10 @@ Amplitude.prototype.isNewSession = function() {
   return this._newSession;
 };
 
+Amplitude.prototype.getSessionId = function() {
+  return this._sessionId;
+};
+
 Amplitude.prototype.nextEventId = function() {
   this._eventId++;
   return this._eventId;

amplitude.min.js

@@ -184,6 +184,10 @@ Amplitude.prototype.isNewSession = function() {
   return this._newSession;
 };
 
+Amplitude.prototype.getSessionId = function() {
+  return this._sessionId;
+};
+
 Amplitude.prototype.nextEventId = function() {
   this._eventId++;
   return this._eventId;

src/amplitude.js

@@ -1288,7 +1288,6 @@ describe('Amplitude', function() {
       amplitude2.setUserProperties({'key':'value'}); // identify event at time 30
 
       var cookieData = JSON.parse(localStorage.getItem('amp_cookiestore_amplitude_id'));
-      console.log(cookieData);
       assert.deepEqual(cookieData, {
         'deviceId': deviceId,
         'userId': null,
@@ -1623,6 +1622,16 @@ describe('Amplitude', function() {
       assert.notEqual(amplitude._sessionId, sessionId);
       assert.equal(events[0].session_id, amplitude._sessionId);
     });
+
+    it('should be fetched correctly by getSessionId', function() {
+      var timestamp = 1000;
+      clock.tick(timestamp);
+      var amplitude2 = new Amplitude();
+      amplitude2.init(apiKey);
+      assert.equal(amplitude2._sessionId, timestamp);
+      assert.equal(amplitude2.getSessionId(), timestamp);
+      assert.equal(amplitude2.getSessionId(), amplitude2._sessionId);
+    });
   });
 
   describe('truncate', function() {