[FSSDK-11968] fix: pass error decision for cmab failure (#607)

* fix: fix typo in log message

- Update log message to remove unnecessary punctuation
- Correct typo in log message for failed CMAB data fetch in experiment

* fix: correct error handling logic

- Update FeatureDecision struct to include 'error' property
- Update handling of errors in OptimizelyClient+Decide.swift
- Adjust guard clause to properly check for errors before decision making

Author: muzahidul-opti

Sources/Implementation/DefaultDecisionService.swift

@@ -21,6 +21,7 @@ struct FeatureDecision {
     let variation: Variation?
     let source: String
     var cmabUUID: String?
+    var error = false
 }
 
 struct VariationDecision {
@@ -125,7 +126,7 @@ class DefaultDecisionService: OPTDecisionService {
             case .failure:
                 let info = LogMessage.cmabFetchFailed(experiment.key)
                 self.logger.e(info)
-                reasons.addInfo(info)
+                reasons.addError(info)
                 let nilVariation = VariationDecision(variation: nil, cmabError: true, cmabUUID: nil)
                 return DecisionResponse(result: nilVariation, reasons: reasons)
         }
@@ -457,7 +458,7 @@ class DefaultDecisionService: OPTDecisionService {
                     if result.cmabError {
                         // For CMAB - we're supposed to get decision from the server.
                         // If failed, return decision with nil variation, so the client can take care of them.
-                        let featureDecision = FeatureDecision(experiment: experiment, variation: nil, source: Constants.DecisionSource.featureTest.rawValue)
+                        let featureDecision = FeatureDecision(experiment: experiment, variation: nil, source: Constants.DecisionSource.featureTest.rawValue, error: true)
                         return DecisionResponse(result: featureDecision, reasons: reasons)
                     } else if let variation = result.variation {
                         let featureDecision = FeatureDecision(experiment: experiment, variation: variation, source: Constants.DecisionSource.featureTest.rawValue, cmabUUID: result.cmabUUID)

Sources/Optimizely+Decide/OptimizelyClient+Decide.swift

@@ -297,6 +297,12 @@ extension OptimizelyClient {
             return OptimizelyDecision.errorDecision(key: flagKey, user: user, error: .featureKeyInvalid(flagKey))
         }
 
+        let error = flagDecision?.error ?? false
+        
+        guard !error else {
+            return OptimizelyDecision.errorDecision(key: flagKey, user: user, reasons: decisionReasons.toReport())
+        }
+        
         let userId = user.userId
         let attributes = user.attributes
         let flagEnabled = flagDecision?.variation?.featureEnabled ?? false

Sources/Optimizely+Decide/OptimizelyDecision.swift

@@ -52,6 +52,16 @@ extension OptimizelyDecision {
                                   reasons: [error.reason])
     }
 
+    static func errorDecision(key: String, user: OptimizelyUserContext, reasons: [String]) -> OptimizelyDecision {
+        return OptimizelyDecision(variationKey: nil,
+                                  enabled: false,
+                                  variables: OptimizelyJSON.createEmpty(),
+                                  ruleKey: nil,
+                                  flagKey: key,
+                                  userContext: user,
+                                  reasons: reasons)
+    }
+    
     var hasFailed: Bool {
         return variationKey == nil
     }

Sources/Utils/LogMessage.swift

@@ -148,7 +148,7 @@ extension LogMessage: CustomStringConvertible {
         case .failedToAssignValue:                                              message = "Value for path could not be assigned to provided type."
         case .valueForKeyNotFound(let key):                                     message = "Value for JSON key (\(key)) not found."
         case .lowPeriodicDownloadInterval:                                      message = "Polling intervals below 30 seconds are not recommended."
-        case .cmabFetchFailed(let key):                                         message = "Failed to fetch CMAB data for experiment: \(key)."
+        case .cmabFetchFailed(let key):                                         message = "Failed to fetch CMAB data for experiment \(key)."
         case .cmabNotSupportedInSyncMode:                                       message = "CMAB is not supported in sync mode."
         }