wip: add flag decision method

Author: muzahidul-opti

Sources/Implementation/DefaultDecisionService.swift

@@ -226,23 +226,11 @@ class DefaultDecisionService: OPTDecisionService {
         var decisions = [DecisionResponse<FeatureDecision>]()
 
         for featureFlag in featureFlags {
-            var decisionResponse = getVariationForFeature(config: config, featureFlag: featureFlag, user: user, userProfileTracker: profileTracker)
+            let flagDecisionResponse = getDecisionForFlag(config: config, featureFlag: featureFlag, user: user, userProfileTracker: profileTracker)
+            reasons.merge(flagDecisionResponse.reasons)
 
-            reasons.merge(decisionResponse.reasons)
-            
-            if let decision = decisionResponse.result {
+            if let decision = flagDecisionResponse.result {
                 decisions.append(DecisionResponse(result: decision, reasons: reasons))
-                continue
-            }
-            
-            decisionResponse = getVariationForFeatureRollout(config: config, featureFlag: featureFlag, user: user)
-            
-            reasons.merge(decisionResponse.reasons)
-            
-            if let decision = decisionResponse.result {
-                decisions.append(DecisionResponse(result: decision, reasons: reasons))
-            } else {
-                decisions.append(DecisionResponse(result: nil, reasons: reasons))
             }
         }
 
@@ -254,6 +242,43 @@ class DefaultDecisionService: OPTDecisionService {
         return decisions
     }
 
+    func getDecisionForFlag(config: ProjectConfig,
+                            featureFlag: FeatureFlag,
+                            user: OptimizelyUserContext,
+                            userProfileTracker: UserProfileTracker? = nil,
+                            options: [OptimizelyDecideOption]? = nil) -> DecisionResponse<FeatureDecision> {
+        let reasons = DecisionReasons(options: options)
+        
+        let holdouts = config.getHoldoutForFlag(id: featureFlag.id)
+        for holdout in holdouts {
+            let holdoutDecision = getVariationForHoldout(config: config,
+                                                         flagKey: featureFlag.key,
+                                                         holdout: holdout,
+                                                         user: user)
+            reasons.merge(holdoutDecision.reasons)
+            if let variation = holdoutDecision.result {
+                let featureDicision = FeatureDecision(experiment: holdout, variation: variation, source: Constants.DecisionSource.holdout.rawValue)
+                return DecisionResponse(result: featureDicision, reasons: reasons)
+            }
+        }
+        
+        let flagExpDecision = getVariationForFeatureExperiments(config: config, featureFlag: featureFlag, user: user, userProfileTracker: userProfileTracker)
+        reasons.merge(flagExpDecision.reasons)
+        
+        if let decision = flagExpDecision.result {
+            return DecisionResponse(result: decision, reasons: reasons)
+        }
+        
+        let rolloutDecision = getVariationForFeatureRollout(config: config, featureFlag: featureFlag, user: user)
+        reasons.merge(rolloutDecision.reasons)
+        
+        if let decision = rolloutDecision.result {
+            return DecisionResponse(result: decision, reasons: reasons)
+        } else {
+            return DecisionResponse(result: nil, reasons: reasons)
+        }
+    }
+    
     /// Determines the feature decision for a feature flag, considering experiments and holdouts.
     /// - Parameters:
     ///   - config: The project configuration.
@@ -262,26 +287,13 @@ class DefaultDecisionService: OPTDecisionService {
     ///   - userProfileTracker: Optional tracker for user profile data.
     ///   - options: Optional decision options.
     /// - Returns: A `DecisionResponse` with the feature decision (if any) and reasons.
-    func getVariationForFeature(config: ProjectConfig,
+    func getVariationForFeatureExperiments(config: ProjectConfig,
                                 featureFlag: FeatureFlag,
                                 user: OptimizelyUserContext,
                                 userProfileTracker: UserProfileTracker? = nil,
                                 options: [OptimizelyDecideOption]? = nil) -> DecisionResponse<FeatureDecision> {
         let reasons = DecisionReasons(options: options)
 
-        let holdouts = config.getHoldoutForFlag(id: featureFlag.id)
-        for holdout in holdouts {
-            let dicisionResponse = getVariationForHoldout(config: config,
-                                                          flagKey: featureFlag.key,
-                                                          holdout: holdout,
-                                                          user: user)
-            reasons.merge(dicisionResponse.reasons)
-            if let variation = dicisionResponse.result {
-                let featureDicision = FeatureDecision(experiment: holdout, variation: variation, source: Constants.DecisionSource.holdout.rawValue)
-                return DecisionResponse(result: featureDicision, reasons: reasons)
-            }
-        }
-        
         let experimentIds = featureFlag.experimentIds
         if experimentIds.isEmpty {
             let info = LogMessage.featureHasNoExperiments(featureFlag.key)

Tests/OptimizelyTests-Common/DecisionListenerTests.swift

@@ -1263,7 +1263,7 @@ class FakeDecisionService: DefaultDecisionService {
         return DecisionResponse.responseNoReasons(result: featureDecision)
     }
 
-    override func getVariationForFeature(config: ProjectConfig, featureFlag: FeatureFlag, user: OptimizelyUserContext, userProfileTracker: UserProfileTracker? = nil, options: [OptimizelyDecideOption]? = nil) -> DecisionResponse<FeatureDecision> {
+    override func getVariationForFeatureExperiments(config: ProjectConfig, featureFlag: FeatureFlag, user: OptimizelyUserContext, userProfileTracker: UserProfileTracker? = nil, options: [OptimizelyDecideOption]? = nil) -> DecisionResponse<FeatureDecision> {
         guard let experiment = self.experiment, let tmpVariation = self.variation else {
             return DecisionResponse.nilNoReasons()
         }

Tests/OptimizelyTests-Common/DecisionServiceTests_Features.swift

@@ -258,7 +258,7 @@ class DecisionServiceTests_Features: XCTestCase {
 extension DecisionServiceTests_Features {
 
     func testGetVariationForFeatureExperimentWhenMatched() {
-        let pair = self.decisionService.getVariationForFeature(config: config,
+        let pair = self.decisionService.getVariationForFeatureExperiments(config: config,
                                                                          featureFlag: featureFlag,
                                                                          user: optimizely.createUserContext(userId: kUserId,
                                                                                                             attributes: kAttributesCountryMatch)).result
@@ -268,7 +268,7 @@ extension DecisionServiceTests_Features {
     }
 
     func testGetVariationForFeatureExperimentWhenNotMatched() {
-        let pair = self.decisionService.getVariationForFeature(config: config,
+        let pair = self.decisionService.getVariationForFeatureExperiments(config: config,
                                                                          featureFlag: featureFlag,
                                                                          user: optimizely.createUserContext(userId: kUserId,
                                                                                                             attributes: kAttributesCountryNotMatch)).result
@@ -280,7 +280,7 @@ extension DecisionServiceTests_Features {
         featureFlag.experimentIds = ["99999"]   // not-existing experiment
         self.config.project.featureFlags = [featureFlag]
 
-        let pair = self.decisionService.getVariationForFeature(config: config,
+        let pair = self.decisionService.getVariationForFeatureExperiments(config: config,
                                                                          featureFlag: featureFlag,
                                                                          user: optimizely.createUserContext(userId: kUserId,
                                                                                                             attributes: kAttributesCountryMatch)).result

Tests/OptimizelyTests-Common/OptimizelyUserContextTests_Decide_Reasons.swift

@@ -17,7 +17,6 @@
 import XCTest
 
 class OptimizelyUserContextTests_Decide_Reasons: XCTestCase {
-    /// Need to add testcases for holdout
     let kUserId = "tester"
 
     var optimizely: OptimizelyClient!