fix(decision-service): Adds bucketing id in getVariationForRollout method. (#200)

(cherry picked from commit 9812af8)

Author: mfahadahmed

packages/optimizely-sdk/lib/core/decision_service/index.js

@@ -383,6 +383,8 @@ DecisionService.prototype._getVariationForRollout = function(feature, userId, at
     };
   }
 
+  var bucketingId = this._getBucketingId(userId, attributes);
+
   // The end index is length - 1 because the last experiment is assumed to be
   // "everyone else", which will be evaluated separately outside this loop
   var endIndex = rollout.experiments.length - 1;
@@ -400,7 +402,7 @@ DecisionService.prototype._getVariationForRollout = function(feature, userId, at
     }
 
     this.logger.log(LOG_LEVEL.DEBUG, sprintf(LOG_MESSAGES.USER_MEETS_CONDITIONS_FOR_TARGETING_RULE, MODULE_NAME, userId, index + 1));
-    bucketerParams = this.__buildBucketerParams(experiment.key, userId, userId);
+    bucketerParams = this.__buildBucketerParams(experiment.key, bucketingId, userId);
     variationId = bucketer.bucket(bucketerParams);
     variation = this.configObj.variationIdMap[variationId];
     if (variation) {
@@ -418,7 +420,7 @@ DecisionService.prototype._getVariationForRollout = function(feature, userId, at
 
   var everyoneElseExperiment = this.configObj.experimentKeyMap[rollout.experiments[endIndex].key];
   if (this.__checkIfUserIsInAudience(everyoneElseExperiment.key, userId, attributes)) {
-    bucketerParams = this.__buildBucketerParams(everyoneElseExperiment.key, userId, userId);
+    bucketerParams = this.__buildBucketerParams(everyoneElseExperiment.key, bucketingId, userId);
     variationId = bucketer.bucket(bucketerParams);
     variation = this.configObj.variationIdMap[variationId];
     if (variation) {

packages/optimizely-sdk/lib/core/decision_service/index.tests.js

@@ -1355,5 +1355,47 @@ describe('lib/core/decision_service', function() {
         });
       });
     });
+
+    describe('_getVariationForRollout', function() {
+      var feature;
+      var configObj;
+      var decisionService;
+      var __buildBucketerParamsSpy;
+
+      beforeEach(function() {
+        configObj = projectConfig.createProjectConfig(testDataWithFeatures);
+        feature = configObj.featureKeyMap.test_feature;
+        decisionService = DecisionService.createDecisionService({
+          configObj: configObj,
+          logger: logger.createLogger({logLevel: LOG_LEVEL.INFO}),
+        });
+        __buildBucketerParamsSpy = sinon.spy(decisionService, '__buildBucketerParams');
+      });
+      
+      afterEach(function() {
+        __buildBucketerParamsSpy.restore();
+      });
+
+      it('should call __buildBucketerParams with user Id when bucketing Id is not provided in the attributes', function () {
+        var attributes = { test_attribute: 'test_value' };
+        decisionService._getVariationForRollout(feature, 'testUser', attributes);
+
+        sinon.assert.callCount(__buildBucketerParamsSpy, 2);
+        sinon.assert.calledWithExactly(__buildBucketerParamsSpy, '594031', 'testUser', 'testUser');
+        sinon.assert.calledWithExactly(__buildBucketerParamsSpy, '594037', 'testUser', 'testUser');
+      });
+
+      it('should call __buildBucketerParams with bucketing Id when bucketing Id is provided in the attributes', function () {
+        var attributes = {
+          test_attribute: 'test_value',
+          $opt_bucketing_id: 'abcdefg' 
+        };
+        decisionService._getVariationForRollout(feature, 'testUser', attributes);
+        
+        sinon.assert.callCount(__buildBucketerParamsSpy, 2);
+        sinon.assert.calledWithExactly(__buildBucketerParamsSpy, '594031', 'abcdefg', 'testUser');
+        sinon.assert.calledWithExactly(__buildBucketerParamsSpy, '594037', 'abcdefg', 'testUser');
+      });
+    });
   });
 });