From 37aebd0f00316b25e253324245a6cdb863b9b8c8 Mon Sep 17 00:00:00 2001
From: jsantiago-eProsima
 <90755661+jsantiago-eProsima@users.noreply.github.com>
Date: Fri, 18 Feb 2022 08:49:10 +0100
Subject: [PATCH] Added PrintTo function for null_type (#2462)

* Added workaround for GCC's incorrect GTest handling of null_types

Signed-off-by: Javier Santiago <javiersantiago@eprosima.com>

* Added GTest printer for dds::core::null_type

Signed-off-by: Javier Santiago <javiersantiago@eprosima.com>
(cherry picked from commit 53ac0123a350d8b03356d5e055bf9bde4c612682)
---
 test/unittest/common/GTestPrinters.hpp        | 43 +++++++++++++++++++
 .../dds/participant/ParticipantTests.cpp      |  1 +
 2 files changed, 44 insertions(+)
 create mode 100644 test/unittest/common/GTestPrinters.hpp

diff --git a/test/unittest/common/GTestPrinters.hpp b/test/unittest/common/GTestPrinters.hpp
new file mode 100644
index 00000000000..48298803e00
--- /dev/null
+++ b/test/unittest/common/GTestPrinters.hpp
@@ -0,0 +1,43 @@
+// Copyright 2022 Proyectos y Sistemas de Mantenimiento SL (eProsima).
+//
+// 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.
+
+/**
+ * @file GTestPrinters.hpp
+ *
+ */
+
+#ifndef GTESTPRINTERS_HPP
+#define GTESTPRINTERS_HPP
+
+#include <dds/core/types.hpp>
+
+/**
+ * Workaround for GCC to behave properly and let Google Test know what to do with null_types
+ * when printing an ASSERT/EXPECT result. Documentation can be found here:
+ * https://github.com/google/googletest/blob/main/googletest/include/gtest/gtest-printers.h
+ *
+ */
+namespace dds {
+namespace core {
+void PrintTo(
+        const null_type,
+        std::ostream* os)
+{
+    *os << "::dds::core::null_type";
+}
+
+} // namespace core
+} // namespace dds
+
+#endif // GTESTPRINTERS_HPP
diff --git a/test/unittest/dds/participant/ParticipantTests.cpp b/test/unittest/dds/participant/ParticipantTests.cpp
index 31eef1d3ad9..ec4f1920b74 100644
--- a/test/unittest/dds/participant/ParticipantTests.cpp
+++ b/test/unittest/dds/participant/ParticipantTests.cpp
@@ -60,6 +60,7 @@
 #include <fastdds/domain/DomainParticipantImpl.hpp>
 #include <utils/SystemInfo.hpp>
 
+#include "../../common/GTestPrinters.hpp"
 #include "../../logging/mock/MockConsumer.h"
 
 namespace eprosima {