Remove trailing conditionless null-valued rules

2 files changed, 34 insertions, 0 deletions

diff --git a/flags/src/main/java/com/yahoo/vespa/flags/json/FlagData.java b/flags/src/main/java/com/yahoo/vespa/flags/json/FlagData.java
index acda3b9db42..8a5366c65e2 100644
--- a/flags/src/main/java/com/yahoo/vespa/flags/json/FlagData.java
+++ b/flags/src/main/java/com/yahoo/vespa/flags/json/FlagData.java
@@ -70,6 +70,16 @@ public class FlagData {
             }
         }
 
+        // Remove trailing rules that have no conditions and no value to apply.
+        while (newRules.size() > 0) {
+            Rule lastRule = newRules.get(newRules.size() - 1);
+            if (lastRule.conditions().isEmpty() && lastRule.getValueToApply().isEmpty()) {
+                newRules.remove(newRules.size() - 1);
+            } else {
+                break;
+            }
+        }
+
         FetchVector newDefaultFetchVector = defaultFetchVector.without(fetchVector.dimensions());
 
         return new FlagData(id, newDefaultFetchVector, newRules);
diff --git a/flags/src/test/java/com/yahoo/vespa/flags/json/FlagDataTest.java b/flags/src/test/java/com/yahoo/vespa/flags/json/FlagDataTest.java
index c7da1abe7e2..4ec0ea0652f 100644
--- a/flags/src/test/java/com/yahoo/vespa/flags/json/FlagDataTest.java
+++ b/flags/src/test/java/com/yahoo/vespa/flags/json/FlagDataTest.java
@@ -5,6 +5,7 @@ import com.yahoo.vespa.flags.FetchVector;
 import com.yahoo.vespa.flags.RawFlag;
 import org.junit.jupiter.api.Test;
 
+import java.util.List;
 import java.util.Optional;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -212,6 +213,29 @@ public class FlagDataTest {
         assertTrue(fullyResolved.isEmpty());
     }
 
+    @Test
+    void testRemovalOfSentinelRuleWithNullValue() {
+        FlagData data = FlagData.deserialize("""
+                                             {
+                                                 "id": "id1",
+                                                 "rules": [
+                                                     {
+                                                         "conditions": [
+                                                             {
+                                                                 "type": "whitelist",
+                                                                 "dimension": "zone",
+                                                                 "values": [ "zone1", "zone2" ]
+                                                             }
+                                                         ],
+                                                         "value": null
+                                                     }
+                                                 ]
+                                             }""");
+        FlagData flagData = data.partialResolve(vector.with(FetchVector.Dimension.ZONE_ID, "zone3"));
+        assertEquals(flagData, new FlagData(data.id(), new FetchVector(), List.of()));
+        assertTrue(flagData.isEmpty());
+    }
+
     private void verify(Optional<String> expectedValue, FetchVector vector) {
         FlagData data = FlagData.deserialize(json);
         assertEquals("id1", data.id().toString());