update: enhance error handling by specifying CMAB error messages in decision responses

Author: FarhanAnjum-opti

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -1451,10 +1451,11 @@ private Map<String, OptimizelyDecision> decideForKeys(@Nonnull OptimizelyUserCon
         for (int i = 0; i < flagsWithoutForcedDecision.size(); i++) {
             DecisionResponse<FeatureDecision> decision = decisionList.get(i);
             boolean error = decision.isError();
+            String experimentKey = decision.getResult().experiment.getKey();
             String flagKey = flagsWithoutForcedDecision.get(i).getKey();
 
             if (error) {
-                OptimizelyDecision optimizelyDecision = OptimizelyDecision.newErrorDecision(flagKey, user, DecisionMessage.DECISION_ERROR.reason(flagKey));
+                OptimizelyDecision optimizelyDecision = OptimizelyDecision.newErrorDecision(flagKey, user, DecisionMessage.CMAB_ERROR.reason(experimentKey));
                 decisionMap.put(flagKey, optimizelyDecision);
                 if (validKeys.contains(flagKey)) {
                     validKeys.remove(flagKey);
@@ -1611,17 +1612,7 @@ private Map<String, OptimizelyDecision> decideForKeysSync(@Nonnull OptimizelyUse
 
         for (int i = 0; i < flagsWithoutForcedDecision.size(); i++) {
             DecisionResponse<FeatureDecision> decision = decisionList.get(i);
-            boolean error = decision.isError();
             String flagKey = flagsWithoutForcedDecision.get(i).getKey();
-
-            if (error) {
-                OptimizelyDecision optimizelyDecision = OptimizelyDecision.newErrorDecision(flagKey, user, DecisionMessage.DECISION_ERROR.reason(flagKey));
-                decisionMap.put(flagKey, optimizelyDecision);
-                if (validKeys.contains(flagKey)) {
-                    validKeys.remove(flagKey);
-                }
-            }
-
             flagDecisions.put(flagKey, decision.getResult());
             decisionReasonsMap.get(flagKey).merge(decision.getReasons());
         }

core-api/src/main/java/com/optimizely/ab/optimizelydecision/DecisionMessage.java

@@ -21,7 +21,7 @@ public enum DecisionMessage {
     SDK_NOT_READY("Optimizely SDK not configured properly yet."),
     FLAG_KEY_INVALID("No flag was found for key \"%s\"."),
     VARIABLE_VALUE_INVALID("Variable value for key \"%s\" is invalid or wrong type."),
-    DECISION_ERROR("Decision service error occured for key \"%s\".");
+    CMAB_ERROR("Failed to fetch CMAB data for experiment %s.");
 
     private String format;