add testing methods

Author: lujiajing1126

xds/src/main/java/io/grpc/xds/client/ControlPlaneClient.java

@@ -205,6 +205,15 @@ boolean isReady() {
     return adsStream != null && adsStream.call != null && adsStream.call.isReady();
   }
 
+  @Nullable
+  @VisibleForTesting
+  Map<XdsResourceType<?>, String> getNonce() {
+    if (adsStream == null) {
+      return null;
+    }
+    return adsStream.respNonces;
+  }
+
   /**
    * Starts a timer for each requested resource that hasn't been responded to and
    * has been waiting for the channel to get ready.

xds/src/main/java/io/grpc/xds/client/XdsClientImpl.java

@@ -84,7 +84,7 @@ public void uncaughtException(Thread t, Throwable e) {
   final Map<ServerInfo, LoadReportClient> serverLrsClientMap =
       new HashMap<>();
 
-  private final Map<ServerInfo, ControlPlaneClient> serverCpClientMap = new HashMap<>();
+  final Map<ServerInfo, ControlPlaneClient> serverCpClientMap = new HashMap<>();
   private final Map<XdsResourceType<? extends ResourceUpdate>,
       Map<String, ResourceSubscriber<? extends ResourceUpdate>>>
       resourceSubscribers = new HashMap<>();

xds/src/test/java/io/grpc/xds/GrpcXdsClientImplTestBase.java

@@ -87,6 +87,7 @@
 import io.grpc.xds.client.Bootstrapper.BootstrapInfo;
 import io.grpc.xds.client.Bootstrapper.CertificateProviderInfo;
 import io.grpc.xds.client.Bootstrapper.ServerInfo;
+import io.grpc.xds.client.ControlPlaneClientTestBase;
 import io.grpc.xds.client.EnvoyProtoData.Node;
 import io.grpc.xds.client.LoadStatsManager2.ClusterDropStats;
 import io.grpc.xds.client.Locality;
@@ -140,7 +141,7 @@
 @RunWith(JUnit4.class)
 // The base class was used to test both xds v2 and v3. V2 is dropped now so the base class is not
 // necessary. Still keep it for future version usage. Remove if too much trouble to maintain.
-public abstract class GrpcXdsClientImplTestBase {
+public abstract class GrpcXdsClientImplTestBase extends ControlPlaneClientTestBase {
   private static final String SERVER_URI = "trafficdirector.googleapis.com";
   private static final String SERVER_URI_CUSTOME_AUTHORITY = "trafficdirector2.googleapis.com";
   private static final String SERVER_URI_EMPTY_AUTHORITY = "trafficdirector3.googleapis.com";
@@ -2758,7 +2759,7 @@ public void edsResourceNotFound() {
   }
 
   @Test
-  public void edsAllowRespondAfterUnsubscription() {
+  public void edsCleanupNonceAfterUnsubscription() {
     Assume.assumeFalse(ignoreResourceDeletion());
 
     // Suppose we have an EDS subscription A.1
@@ -2776,6 +2777,7 @@ public void edsAllowRespondAfterUnsubscription() {
     call.sendResponse(EDS, resourcesV1.values().asList(), VERSION_1, "0000");
     // {A.1} -> ACK, version 1
     verifyResourceMetadataAcked(EDS, "A.1", resourcesV1.get("A.1"), VERSION_1, TIME_INCREMENT);
+    call.verifyRequest(EDS, "A.1", VERSION_1, "0000", NODE);
     verify(edsResourceWatcher, times(1)).onChanged(any());
 
     // trigger an EDS resource unsubscription.
@@ -2784,17 +2786,9 @@ public void edsAllowRespondAfterUnsubscription() {
     // 1) the EDS unsubscription caused by CDS PUSH e1 (client-side) and,
     // 2) the immediate EDS PUSH from XdsServer (server-side) after CDS PUSH e1 (event e2).
     xdsClient.cancelXdsResourceWatch(XdsEndpointResource.getInstance(), "A.1", edsResourceWatcher);
-    // FIX(1): allow to send empty subscription
-    call.verifyRequest(EDS, Collections.emptyList(), VERSION_1, "0000", NODE);
     verifySubscribedResourcesMetadataSizes(0, 0, 0, 0);
-    // An EDS PUSH after CDS PUSH e1.
-    List<Message> endpointsV2 = ImmutableList.of(lbEndpointHealthy);
-    ImmutableMap<String, Any> resourcesV2 = ImmutableMap.of(
-            "A.1", Any.pack(mf.buildClusterLoadAssignment("A.1", endpointsV2, dropOverloads)));
-    call.sendResponse(EDS, resourcesV2.values().asList(), VERSION_2, "0001");
-    // FIX(2): allow to update resource version even if the subscription resource is empty
-    call.verifyRequest(EDS, Collections.emptyList(), VERSION_2, "0001", NODE);
-    verifyNoMoreInteractions(edsResourceWatcher);
+    // The nonce has been removed
+    assertThat(getNonceForResourceType(xdsClient, xdsServerInfo, EDS)).isNull();
   }
 
   @Test

xds/src/test/java/io/grpc/xds/client/ControlPlaneClientTestBase.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc.xds.client;
+
+import java.util.Map;
+
+public abstract class ControlPlaneClientTestBase {
+    protected static String getNonceForResourceType(XdsClientImpl xdsClient, Bootstrapper.ServerInfo serverInfo, XdsResourceType<?> type) {
+        ControlPlaneClient controlPlaneClient = xdsClient.serverCpClientMap.get(serverInfo);
+        Map<XdsResourceType<?>, String> nonceMap = controlPlaneClient.getNonce();
+        if (nonceMap == null) {
+            return null;
+        }
+        return nonceMap.get(type);
+    }
+}