fix: log error message when user allocated to vacated space in group or experiment (#366)

Summary:

When a user is allocated to space in a group that used to be occupied by an experiment, but is now unallocated, the JS SDK logs an error message. This is not an error, so it shouldn't log an error message.

Author: fayyazarshad

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

@@ -87,10 +87,10 @@ module.exports = {
     bucketerParams.logger.log(LOG_LEVEL.DEBUG, bucketedUserLogMessage);
 
     var entityId = module.exports._findBucket(bucketValue, bucketerParams.trafficAllocationConfig);
-    if (entityId === null) {
+    if (!entityId) {
       var userHasNoVariationLogMessage = sprintf(LOG_MESSAGES.USER_HAS_NO_VARIATION, MODULE_NAME, bucketerParams.userId, bucketerParams.experimentKey);
       bucketerParams.logger.log(LOG_LEVEL.DEBUG, userHasNoVariationLogMessage);
-    } else if (entityId === '' || !bucketerParams.variationIdMap.hasOwnProperty(entityId)) {
+    } else if (!bucketerParams.variationIdMap.hasOwnProperty(entityId)) {
       var invalidVariationIdLogMessage = sprintf(LOG_MESSAGES.INVALID_VARIATION_ID, MODULE_NAME);
       bucketerParams.logger.log(LOG_LEVEL.WARNING, invalidVariationIdLogMessage);
       return null;

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

@@ -258,7 +258,7 @@ describe('lib/core/bucketer', function() {
         it('should return null', function() {
           var bucketerParamsTest1 = cloneDeep(bucketerParams);
           bucketerParamsTest1.userId = 'ppid1';
-          expect(bucketer.bucket(bucketerParamsTest1)).to.equal(null);
+          expect(bucketer.bucket(bucketerParamsTest1)).to.equal('');
         });
       });
 

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

@@ -349,7 +349,7 @@ DecisionService.prototype._getVariationForFeatureExperiment = function(configObj
 
 DecisionService.prototype._getExperimentInGroup = function(configObj, group, userId) {
   var experimentId = bucketer.bucketUserIntoExperiment(group, userId, userId, this.logger);
-  if (experimentId !== null) {
+  if (experimentId) {
     this.logger.log(LOG_LEVEL.INFO, sprintf(LOG_MESSAGES.USER_BUCKETED_INTO_EXPERIMENT_IN_GROUP, MODULE_NAME, userId, experimentId, group.id));
     var experiment = projectConfig.getExperimentFromId(configObj, experimentId, this.logger);
     if (experiment) {