sending empty map in case when null is passed in attributes listener

Author: mnoman09

core-api/src/main/java/com/optimizely/ab/notification/DecisionNotificationListener.java

@@ -17,6 +17,7 @@
 package com.optimizely.ab.notification;
 
 import javax.annotation.Nonnull;
+import java.util.HashMap;
 import java.util.Map;
 
 public abstract class DecisionNotificationListener implements NotificationListener, DecisionNotificationListenerInterface {
@@ -36,8 +37,9 @@ public final void notify(Object... args) {
         if (args[2] != null) {
             assert (args[2] instanceof java.util.Map);
             attributes = (Map<String, ?>) args[2];
+        } else {
+            attributes = new HashMap<>();
         }
-        ;
         assert (args[3] instanceof java.util.Map);
         Map<String, ?> decisionInfo = (Map<String, ?>) args[3];
         onDecision(type, userId, attributes, decisionInfo);

core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java

@@ -2641,6 +2641,7 @@ private DecisionNotificationListener getDecisionListener(final String testType,
             public void onDecision(@Nonnull String type, @Nonnull String userId, @Nonnull Map<String, ?> attributes, @Nonnull Map<String, ?> decisionInfo) {
                 assertEquals(type, testType);
                 assertEquals(userId, testUserId);
+                assertEquals(attributes, testUserAttributes);
                 for (Map.Entry<String, ?> entry : attributes.entrySet()) {
                     assertEquals(testUserAttributes.get(entry.getKey()), entry.getValue());
                 }
@@ -2702,7 +2703,7 @@ public void getFeatureVariableWithListenerUserInExperimentFeatureOn() throws Exc
     /**
      * Verify that the {@link Optimizely#getFeatureVariableString(String, String, String, Map)}
      * notification listener of getFeatureVariableString is called when feature is in experiment and feature enabled is false
-     * than default value will get returned
+     * than default value will get returned and passing null attribute will send empty map instead of null
      */
     @Test
     public void getFeatureVariableWithListenerUserInExperimentFeatureOff() {
@@ -2718,7 +2719,6 @@ public void getFeatureVariableWithListenerUserInExperimentFeatureOff() {
             .build();
 
         final Map<String, String> testUserAttributes = new HashMap<>();
-        testUserAttributes.put(ATTRIBUTE_HOUSE_KEY, AUDIENCE_GRYFFINDOR_VALUE);
 
         final Map<String, Object> testDecisionInfoMap = new HashMap<>();
         testDecisionInfoMap.put(DecisionInfoEnums.GetFeatureVariableDecisionInfo.SOURCE_EXPERIMENT_KEY.toString(), "multivariate_experiment");
@@ -2740,7 +2740,7 @@ public void getFeatureVariableWithListenerUserInExperimentFeatureOff() {
             validFeatureKey,
             validVariableKey,
             userID,
-            Collections.singletonMap(ATTRIBUTE_HOUSE_KEY, AUDIENCE_GRYFFINDOR_VALUE)),
+            null),
             expectedValue);
 
         assertTrue(optimizely.notificationCenter.removeNotificationListener(notificationId));