Make test actually fail without sysprop and then make it pass again

Author: DaveCTurner

qa/serverless-system-properties/build.gradle

@@ -7,8 +7,6 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import org.apache.tools.ant.filters.ReplaceTokens
-
 apply plugin: 'elasticsearch.build'
 
 dependencies {
@@ -18,5 +16,5 @@ dependencies {
 
 tasks.named("test").configure {
   systemProperty 'es.stateless.allow.index.refresh_interval.override', 'true'
-//  systemProperty 'es.serverless_transport', 'true'
+  systemProperty 'es.serverless_transport', 'true'
 }

qa/serverless-system-properties/src/test/java/org/elasticsearch/transport/ServerlessTransportHandshakeTests.java

@@ -9,6 +9,7 @@
 
 package org.elasticsearch.transport;
 
+import org.apache.logging.log4j.Level;
 import org.elasticsearch.Build;
 import org.elasticsearch.TransportVersion;
 import org.elasticsearch.cluster.node.DiscoveryNodeUtils;
@@ -19,6 +20,7 @@
 import org.elasticsearch.common.util.PageCacheRecycler;
 import org.elasticsearch.indices.breaker.NoneCircuitBreakerService;
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.test.MockLog;
 import org.elasticsearch.test.transport.MockTransportService;
 import org.elasticsearch.threadpool.TestThreadPool;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -94,7 +96,7 @@ public static void terminateThreadPool() {
         threadPool = null;
     }
 
-    public void testAcceptsMismatchedServerlessBuildHash() {
+    public void testAcceptsMismatchedServerlessBuildHashWithoutWarning() {
         assumeTrue("Current build needs to be a snapshot", Build.current().isSnapshot());
         final var transportInterceptorA = new BuildHashModifyingTransportInterceptor();
         final var transportInterceptorB = new BuildHashModifyingTransportInterceptor();
@@ -104,8 +106,14 @@ public void testAcceptsMismatchedServerlessBuildHash() {
             .build();
         final TransportService transportServiceA = startServices("TS_A", settings, transportInterceptorA);
         final TransportService transportServiceB = startServices("TS_B", settings, transportInterceptorB);
-        AbstractSimpleTransportTestCase.connectToNode(transportServiceA, transportServiceB.getLocalNode(), TestProfiles.LIGHT_PROFILE);
-        assertTrue(transportServiceA.nodeConnected(transportServiceB.getLocalNode()));
+        MockLog.assertThatLogger(() -> {
+            AbstractSimpleTransportTestCase.connectToNode(transportServiceA, transportServiceB.getLocalNode(), TestProfiles.LIGHT_PROFILE);
+            assertTrue(transportServiceA.nodeConnected(transportServiceB.getLocalNode()));
+        },
+            TransportService.class,
+            new MockLog.UnseenEventExpectation("incompatible wire format log", TransportService.class.getCanonicalName(), Level.WARN, "*")
+        );
+
     }
 
 }