added the unimplemented_call test to interop_client.cc. Next step is to call this from the driver program, run_interop_tests.py

src/proto/grpc/testing/test.proto

@@ -69,6 +69,9 @@ service TestService {
   // first request.
   rpc HalfDuplexCall(stream StreamingOutputCallRequest)
       returns (stream StreamingOutputCallResponse);
+
+  // A call that no server should implement
+  rpc UnimplementedCall(grpc.testing.Empty) returns (grpc.testing.Empty);
 }
 
 // A simple service NOT implemented at servers so clients can test for

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 == "all") {
     client.DoEmpty();
     client.DoLargeUnary();
@@ -166,6 +169,7 @@ int main(int argc, char** argv) {
     client.DoEmptyStream();
     client.DoStatusWithMessage();
     client.DoCustomMetadata();
+    client.DoUnimplementedMethod();
     // service_account_creds and jwt_token_creds can only run with ssl.
     if (FLAGS_use_tls) {
       grpc::string json_key = GetServiceAccountJsonKey();
@@ -198,7 +202,8 @@ 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);
 

test/cpp/interop/interop_client.cc

@@ -937,5 +937,25 @@ 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;
+
+  gpr_log(GPR_DEBUG, "here");
+
+  Status s = serviceStub_.Get()->UnimplementedCall(
+    &context, request, &response);
+
+  if (!AssertStatusCode(s, StatusCode::UNIMPLEMENTED)) {
+    return false;
+  }
+
+  gpr_log(GPR_DEBUG, "unimplemented rpc done.");
+  return true;
+}
+
 }  // namespace testing
 }  // namespace grpc

test/cpp/interop/interop_client.h

@@ -79,6 +79,7 @@ class InteropClient {
   bool DoEmptyStream();
   bool DoStatusWithMessage();
   bool DoCustomMetadata();
+  bool DoUnimplementedMethod();
   // Auth tests.
   // username is a string containing the user email
   bool DoJwtTokenCreds(const grpc::string& username);