feat: Implement trackEvent api

packages/optimizely-sdk/lib/optimizely/index.ts

@@ -1603,7 +1603,6 @@ export default class Optimizely {
    * @param     {OptimizelyDecideOptions[]}  options     An array of options for decision-making.
    * @return    {[key: string]: OptimizelyDecision}      An object of decision results mapped by flag keys.
    */
-
   decideForKeys(
     user: OptimizelyUserContext,
     keys: string[],

packages/optimizely-sdk/lib/optimizely_user_context/index.tests.js

@@ -262,5 +262,27 @@ describe('lib/optimizely_user_context', function() {
         assert.deepEqual(decisionMap, fakeDecisionMap);
       });
     });
+
+    describe('#trackEvent', function() {
+      it('should call track from optimizely client', function() {
+        fakeOptimizely = {
+          track: sinon.stub()
+        };
+        var eventName = 'myEvent';
+        var eventTags = { 'eventTag1': 1000 }
+        var user = new OptimizelyUserContext({
+          optimizely: fakeOptimizely,
+          userId,
+        });
+        user.trackEvent(eventName, eventTags);
+        sinon.assert.calledWithExactly(
+          fakeOptimizely.track,
+          eventName,
+          user.getUserId(),
+          user.getAttributes(),
+          eventTags,
+        );
+      });
+    });
   });
 });

packages/optimizely-sdk/lib/optimizely_user_context/index.ts

@@ -14,7 +14,7 @@
  * limitations under the License.                                           *
  ***************************************************************************/
 import Optimizely from '../../lib/optimizely';
-import { UserAttributes, OptimizelyDecideOptions } from '../../lib/shared_types';
+import { UserAttributes, OptimizelyDecideOptions, EventTags } from '../../lib/shared_types';
 import { OptimizelyDecision } from '../optimizely_decision';
 
 export default class OptimizelyUserContext {
@@ -99,4 +99,13 @@ export default class OptimizelyUserContext {
 
     return this.optimizely.decideAll(this, options);
   }
+
+  /**
+   * Tracks an event.
+   * @param     {string}                     eventName The event name.
+   * @param     {EventTags}                  eventTags An optional map of event tag names to event tag values.
+   */
+  trackEvent(eventName: string, eventTags?: EventTags): void {
+    this.optimizely.track(eventName, this.userId, this.attributes, eventTags);
+  }
 }