fix test

Author: peachisai

instrumentation/nacos-client-2.0/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/nacosclient/v2_0/NacosClientAgentInstrumentationTest.java

@@ -40,6 +40,8 @@
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -88,6 +90,7 @@ void instrumentsGrpcConnectionRequestAdvice() throws Exception {
   void instrumentsRpcClientHandleServerRequestAdvice() throws Exception {
     RpcClient rpcClient = mock(RpcClient.class, withSettings().defaultAnswer(CALLS_REAL_METHODS));
     setField(rpcClient, "serverRequestHandlers", new ArrayList<ServerRequestHandler>());
+    initializeRpcClientConfigIfPresent(rpcClient);
     when(rpcClient.getCurrentServer()).thenReturn(new RpcClient.ServerInfo("127.0.0.1", 9848));
     rpcClient.registerServerRequestHandler(serverRequestHandler());
 
@@ -166,6 +169,62 @@ private static void setField(Object target, String fieldName, Object value) thro
     field.set(target, value);
   }
 
+  private static void initializeRpcClientConfigIfPresent(RpcClient rpcClient) throws Exception {
+    try {
+      Field field = RpcClient.class.getDeclaredField("rpcClientConfig");
+      field.setAccessible(true);
+      if (field.get(rpcClient) != null) {
+        return;
+      }
+      Class<?> configType = field.getType();
+      Object config =
+          mock(
+              configType,
+              invocation -> {
+                Method method = invocation.getMethod();
+                String methodName = method.getName();
+                if ("name".equals(methodName)) {
+                  return "test-rpc-client";
+                }
+                Class<?> returnType = method.getReturnType();
+                if (returnType == boolean.class) {
+                  return false;
+                }
+                if (returnType == int.class) {
+                  return 0;
+                }
+                if (returnType == long.class) {
+                  return 0L;
+                }
+                if (returnType == double.class) {
+                  return 0d;
+                }
+                if (returnType == float.class) {
+                  return 0f;
+                }
+                if (returnType == short.class) {
+                  return (short) 0;
+                }
+                if (returnType == byte.class) {
+                  return (byte) 0;
+                }
+                if (returnType == char.class) {
+                  return (char) 0;
+                }
+                if (returnType == String.class) {
+                  return "";
+                }
+                if (returnType == Map.class) {
+                  return Collections.emptyMap();
+                }
+                return null;
+              });
+      field.set(rpcClient, config);
+    } catch (NoSuchFieldException ignored) {
+      // nacos-client 2.0.0 does not expose rpcClientConfig on RpcClient
+    }
+  }
+
   private static final class TestManagedChannel extends ManagedChannel {
     private final String authority;