fix(whitelisting): Invalid whitelisted variation stops bucketing

OptimizelySDKCore/OptimizelySDKCore/OPTLYDecisionService.m

@@ -76,8 +76,10 @@ - (OPTLYVariation *)getVariation:(NSString *)userId
 
     // ---- check if the experiment is whitelisted ----
     if ([self checkWhitelistingForUser:userId experiment:experiment]) {
-        return [self getWhitelistedVariationForUser:userId
-                                         experiment:experiment];
+        OPTLYVariation *whitelistedVariation = [self getWhitelistedVariationForUser:userId experiment:experiment];
+        if (whitelistedVariation) {
+            return whitelistedVariation;
+        }
     }
 
     // ---- check if a valid variation is stored in the user profile ----

OptimizelySDKCore/OptimizelySDKCoreTests/OPTLYDecisionServiceTest.m

@@ -216,6 +216,28 @@ - (void)testGetVariationWithWhitelistedVariation
     XCTAssert([variation.variationKey isEqualToString:kWhitelistedVariation_test_data_10_experiments], @"Get variation on a whitelisted variation should return: %@, but instead returns: %@.", kWhitelistedVariation_test_data_10_experiments, variation.variationKey);
 }
 
+// whitelisted user having invalid whitelisted variation should return bucketed variation for getVariation
+- (void)testGetVariationWithInvalidWhitelistedVariation {
+
+    OPTLYExperiment *experimentWhitelisted = [self.config getExperimentForKey:@"testExperiment5"];
+    OPTLYVariation *expectedVariation = experimentWhitelisted.variations[0];
+
+    id bucketerMock = OCMPartialMock(self.bucketer);
+    OCMStub([bucketerMock bucketExperiment:experimentWhitelisted
+                           withBucketingId:kWhitelistedUserId_test_data_10_experiments]).andReturn(expectedVariation);
+
+    self.decisionService = [[OPTLYDecisionService alloc] initWithProjectConfig:self.config
+                                                                      bucketer:bucketerMock];
+
+    OPTLYVariation *variation = [self.decisionService getVariation:kWhitelistedUserId_test_data_10_experiments
+                                                        experiment:experimentWhitelisted
+                                                        attributes:nil];
+    XCTAssert([variation.variationKey isEqualToString:expectedVariation.variationKey], @"Get variation on an invalid whitelisted variation should return: %@, but instead returns: %@.", expectedVariation.variationKey, variation.variationKey);
+    OCMVerify([bucketerMock bucketExperiment:experimentWhitelisted withBucketingId:kWhitelistedUserId_test_data_10_experiments]);
+    [bucketerMock stopMocking];
+}
+
+
 // invalid audience should return nil for getVariation
 - (void)testGetVariationWithInvalidAudience
 {

OptimizelySDKCore/OptimizelySDKCoreTests/TestData/test_data_10_experiments.json

@@ -106,7 +106,9 @@
           "variables": []
         }
       ],
-      "forcedVariations": {},
+      "forcedVariations": {
+        "forced_variation_user": "invalid_variation"
+      },
       "id": "6364835526"
     },
     {