Added usersyncers cookie-family-name property validation

src/main/java/org/prebid/server/handler/SetuidHandler.java

@@ -56,6 +56,8 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -103,13 +105,22 @@ public SetuidHandler(long defaultTimeout,
         this.analyticsDelegator = Objects.requireNonNull(analyticsDelegator);
         this.metrics = Objects.requireNonNull(metrics);
         this.timeoutFactory = Objects.requireNonNull(timeoutFactory);
+        this.cookieNameToSyncType = collectMap(bidderCatalog);
+    }
+
+    private static Map<String, UsersyncMethodType> collectMap(BidderCatalog bidderCatalog) {
 
-        cookieNameToSyncType = bidderCatalog.names().stream()
+        final Supplier<Stream<Usersyncer>> usersyncers = () -> bidderCatalog.names()
+                .stream()
                 .filter(bidderCatalog::isActive)
                 .map(bidderCatalog::usersyncerByName)
                 .filter(Optional::isPresent)
                 .map(Optional::get)
-                .distinct() // built-in aliases looks like bidders with the same usersyncers
+                .distinct();
+
+        validateUsersyncers(usersyncers.get());
+
+        return usersyncers.get()
                 .collect(Collectors.toMap(Usersyncer::getCookieFamilyName, SetuidHandler::preferredUserSyncType));
     }
 
@@ -121,6 +132,21 @@ private static UsersyncMethodType preferredUserSyncType(Usersyncer usersyncer) {
                 .get(); // when usersyncer is present, it will contain at least one method
     }
 
+    private static void validateUsersyncers(Stream<Usersyncer> usersyncers) {
+        final Stream<String> cookieFamilyNameDuplicates = usersyncers.map(Usersyncer::getCookieFamilyName)
+                .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))
+                .entrySet()
+                .stream()
+                .filter(name -> name.getValue() > 1)
+                .map(Map.Entry::getKey)
+                .distinct();
+        if (cookieFamilyNameDuplicates.findAny().isPresent()) {
+            throw new IllegalArgumentException(
+                    "Duplicated \"cookie-family-name\" found, values: "
+                            + String.join(", ", cookieFamilyNameDuplicates.toList()));
+        }
+    }
+
     @Override
     public void handle(RoutingContext routingContext) {
         toSetuidContext(routingContext)