4 files changed, 54 insertions, 12 deletions

diff --git a/test/cpp/interop/client.cc b/test/cpp/interop/client.cc
index 999be9d8a3..245e27b2bb 100644
--- a/test/cpp/interop/client.cc
+++ b/test/cpp/interop/client.cc
@@ -79,7 +79,8 @@ DEFINE_string(test_case, "large_unary",
               "slow_consumer : single request with response streaming with "
               "slow client consumer;\n"
               "status_code_and_message: verify status code & message;\n"
-              "timeout_on_sleeping_server: deadline exceeds on stream;\n");
+              "timeout_on_sleeping_server: deadline exceeds on stream;\n"
+              "unimplemented_method: client calls an unimplemented_method;\n");
 DEFINE_string(default_service_account, "",
               "Email of GCE default service account");
 DEFINE_string(service_account_key_file, "",
@@ -149,6 +150,8 @@ int main(int argc, char** argv) {
     client.DoStatusWithMessage();
   } else if (FLAGS_test_case == "custom_metadata") {
     client.DoCustomMetadata();
+  } else if (FLAGS_test_case == "unimplemented_method") {
+    client.DoUnimplementedMethod();
   } else if (FLAGS_test_case == "cacheable_unary") {
     client.DoCacheableUnary();
   } else if (FLAGS_test_case == "all") {
@@ -168,6 +171,7 @@ int main(int argc, char** argv) {
     client.DoEmptyStream();
     client.DoStatusWithMessage();
     client.DoCustomMetadata();
+    client.DoUnimplementedMethod();
     client.DoCacheableUnary();
     // service_account_creds and jwt_token_creds can only run with ssl.
     if (FLAGS_use_tls) {
@@ -202,7 +206,8 @@ int main(int argc, char** argv) {
                                "server_compressed_unary",
                                "server_streaming",
                                "status_code_and_message",
-                               "timeout_on_sleeping_server"};
+                               "timeout_on_sleeping_server",
+                               "unimplemented_method"};
     char* joined_testcases =
         gpr_strjoin_sep(testcases, GPR_ARRAY_SIZE(testcases), "\n", NULL);
 
diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index e9a804ccae..effbb8a42e 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -981,5 +981,23 @@ bool InteropClient::DoCustomMetadata() {
   return true;
 }
 
+bool InteropClient::DoUnimplementedMethod() {
+  gpr_log(GPR_DEBUG, "Sending a request for an unimplemented rpc...");
+
+  Empty request = Empty::default_instance();
+  Empty response = Empty::default_instance();
+  ClientContext context;
+
+  Status s = serviceStub_.Get()->UnimplementedMethod(
+    &context, request, &response);
+
+  if (!AssertStatusCode(s, StatusCode::UNIMPLEMENTED)) {
+    return false;
+  }
+
+  gpr_log(GPR_DEBUG, "unimplemented rpc done.");
+  return true;
+}
+
 }  // namespace testing
 }  // namespace grpc
diff --git a/test/cpp/interop/interop_client.h b/test/cpp/interop/interop_client.h
index 1e89f0987d..0a96e7734d 100644
--- a/test/cpp/interop/interop_client.h
+++ b/test/cpp/interop/interop_client.h
@@ -79,6 +79,7 @@ class InteropClient {
   bool DoEmptyStream();
   bool DoStatusWithMessage();
   bool DoCustomMetadata();
+  bool DoUnimplementedMethod();
   bool DoCacheableUnary();
   // Auth tests.
   // username is a string containing the user email
diff --git a/test/cpp/interop/interop_server.cc b/test/cpp/interop/interop_server.cc
index 58f20aa611..e0016148e8 100644
--- a/test/cpp/interop/interop_server.cc
+++ b/test/cpp/interop/interop_server.cc
@@ -83,6 +83,8 @@ const char kEchoInitialMetadataKey[] = "x-grpc-test-echo-initial";
 const char kEchoTrailingBinMetadataKey[] = "x-grpc-test-echo-trailing-bin";
 const char kEchoUserAgentKey[] = "x-grpc-test-echo-useragent";
 
+namespace {
+
 void MaybeEchoMetadata(ServerContext* context) {
   const auto& client_metadata = context->client_metadata();
   GPR_ASSERT(client_metadata.count(kEchoInitialMetadataKey) <= 1);
@@ -146,6 +148,28 @@ bool CheckExpectedCompression(const ServerContext& context,
   return true;
 }
 
+Status RequestedStatusOrOk(const SimpleRequest* request) {
+  if (request->has_response_status()) {
+    return Status(
+      static_cast<grpc::StatusCode>(request->response_status().code()),
+      request->response_status().message());
+  } else {
+    return Status::OK;
+  }
+}
+
+Status RequestedStatusOrOk(const StreamingOutputCallRequest* request) {
+  if (request->has_response_status()) {
+    return Status(
+      static_cast<grpc::StatusCode>(request->response_status().code()),
+      request->response_status().message());
+  } else {
+    return Status::OK;
+  }
+}
+
+} // anonomous namespace
+
 class TestServiceImpl : public TestService::Service {
  public:
   Status EmptyCall(ServerContext* context, const grpc::testing::Empty* request,
@@ -191,13 +215,7 @@ class TestServiceImpl : public TestService::Service {
       }
     }
 
-    if (request->has_response_status()) {
-      return Status(
-          static_cast<grpc::StatusCode>(request->response_status().code()),
-          request->response_status().message());
-    }
-
-    return Status::OK;
+    return RequestedStatusOrOk(request);
   }
 
   Status StreamingOutputCall(
@@ -235,7 +253,7 @@ class TestServiceImpl : public TestService::Service {
       write_success = writer->Write(response, wopts);
     }
     if (write_success) {
-      return Status::OK;
+      return RequestedStatusOrOk(request);
     } else {
       return Status(grpc::StatusCode::INTERNAL, "Error writing response.");
     }
@@ -285,7 +303,7 @@ class TestServiceImpl : public TestService::Service {
       }
     }
     if (write_success) {
-      return Status::OK;
+      return RequestedStatusOrOk(&request);
     } else {
       return Status(grpc::StatusCode::INTERNAL, "Error writing response.");
     }
@@ -314,7 +332,7 @@ class TestServiceImpl : public TestService::Service {
       write_success = stream->Write(response);
     }
     if (write_success) {
-      return Status::OK;
+      return RequestedStatusOrOk(&request);
     } else {
       return Status(grpc::StatusCode::INTERNAL, "Error writing response.");
     }