Fix isFeatureEnabled to always return a boolean value. (#75)

Author: mikeproeng37

src/Optimizely/Optimizely.php

@@ -239,7 +239,7 @@ protected function sendImpressionEvent($experimentKey, $variationKey, $userId, $
             ));
         }
     }
-    
+
     /**
      * Buckets visitor and sends impression event to Optimizely.
      *
@@ -263,7 +263,7 @@ public function activate($experimentKey, $userId, $attributes = null)
         }
 
         $this->sendImpressionEvent($experimentKey, $variationKey, $userId, $attributes);
-        
+
         return $variationKey;
     }
 
@@ -422,28 +422,28 @@ public function isFeatureEnabled($featureFlagKey, $userId, $attributes = null)
     {
         if (!$this->_isValid) {
             $this->_logger->log(Logger::ERROR, "Datafile has invalid format. Failing '".__FUNCTION__."'.");
-            return null;
+            return false;
         }
 
         if (!$featureFlagKey) {
             $this->_logger->log(Logger::ERROR, "Feature Flag key cannot be empty.");
-            return null;
+            return false;
         }
 
         if (!$userId) {
             $this->_logger->log(Logger::ERROR, "User ID cannot be empty.");
-            return null;
+            return false;
         }
 
         $feature_flag = $this->_config->getFeatureFlagFromKey($featureFlagKey);
         if ($feature_flag && (!$feature_flag->getId())) {
             // Error logged in ProjectConfig - getFeatureFlagFromKey
-            return null;
+            return false;
         }
 
         //validate feature flag
         if (!Validator::isFeatureFlagValid($this->_config, $feature_flag)) {
-            return null;
+            return false;
         }
 
         $decision = $this->_decisionService->getVariationForFeature($feature_flag, $userId, $attributes);

tests/OptimizelyTest.php

@@ -1742,44 +1742,44 @@ public function testIsFeatureEnabledGivenInvalidDataFile()
 
     public function testIsFeatureEnabledGivenInvalidArguments()
     {
-        // should return null and log a message when feature flag key is empty
+        // should return false and log a message when feature flag key is empty
         $this->loggerMock->expects($this->at(0))
             ->method('log')
             ->with(Logger::ERROR, "Feature Flag key cannot be empty.");
 
-        $this->assertSame($this->optimizelyObject->isFeatureEnabled("", "user_id"), null);
+        $this->assertSame($this->optimizelyObject->isFeatureEnabled("", "user_id"), false);
 
-        // should return null and log a message when feature flag key is null
+        // should return false and log a message when feature flag key is null
         $this->loggerMock->expects($this->at(0))
             ->method('log')
             ->with(Logger::ERROR, "Feature Flag key cannot be empty.");
 
-        $this->assertSame($this->optimizelyObject->isFeatureEnabled(null, "user_id"), null);
+        $this->assertSame($this->optimizelyObject->isFeatureEnabled(null, "user_id"), false);
 
-        // should return null and log a message when user id is empty
+        // should return false and log a message when user id is empty
         $this->loggerMock->expects($this->at(0))
             ->method('log')
             ->with(Logger::ERROR, "User ID cannot be empty.");
 
-        $this->assertSame($this->optimizelyObject->isFeatureEnabled("boolean_feature", ""), null);
+        $this->assertSame($this->optimizelyObject->isFeatureEnabled("boolean_feature", ""), false);
 
-        // should return null and log a message when user id is null
+        // should return false and log a message when user id is null
         $this->loggerMock->expects($this->at(0))
             ->method('log')
             ->with(Logger::ERROR, "User ID cannot be empty.");
 
-        $this->assertSame($this->optimizelyObject->isFeatureEnabled("boolean_feature", null), null);
+        $this->assertSame($this->optimizelyObject->isFeatureEnabled("boolean_feature", null), false);
     }
 
     public function testIsFeatureEnabledGivenFeatureFlagNotFound()
     {
         $feature_key = "abcd"; // Any string that is not a feature flag key in the data file
 
-        //should return null and log a message when no feature flag found against a valid feature key
+        //should return false and log a message when no feature flag found against a valid feature key
         $this->loggerMock->expects($this->at(0))
         ->method('log')
         ->with(Logger::ERROR, "FeatureFlag Key \"{$feature_key}\" is not in datafile.");
-        $this->assertSame($this->optimizelyObject->isFeatureEnabled($feature_key, "user_id"), null);
+        $this->assertSame($this->optimizelyObject->isFeatureEnabled($feature_key, "user_id"), false);
     }
 
     public function testIsFeatureEnabledGivenInvalidFeatureFlag()
@@ -1798,8 +1798,8 @@ public function testIsFeatureEnabledGivenInvalidFeatureFlag()
         $experimentIds [] = '122241';
         $feature_flag->setExperimentIds($experimentIds);
 
-        //should return null when feature flag is invalid
-        $this->assertSame($optimizelyObj->isFeatureEnabled('mutex_group_feature', "user_id"), null);
+        //should return false when feature flag is invalid
+        $this->assertSame($optimizelyObj->isFeatureEnabled('mutex_group_feature', "user_id"), false);
     }
 
     public function testIsFeatureEnabledGivenFeatureFlagIsNotEnabledForUser()
@@ -2124,7 +2124,7 @@ public function testGetFeatureVariableValueForTypeGivenFeatureFlagIsEnabledForUs
     public function testGetFeatureVariableValueForTypeGivenFeatureFlagIsEnabledForUserAndVariableNotInVariation()
     {
         // should return default value
-        
+
         $decisionServiceMock = $this->getMockBuilder(DecisionService::class)
             ->setConstructorArgs(array($this->loggerMock, $this->projectConfig))
             ->setMethods(array('getVariationForFeature'))