Added Gtest and Jenkinsfile.

.gitmodules

+[submodule "libs/googletest"]
+	path = libs/googletest
+	url = https://github.com/google/googletest.git

CMakeLists.txt

@@ -4,15 +4,25 @@ project(QuantumPong)
 
 cmake_minimum_required(VERSION 3.2)
 
+
+## Options
+option(test "Build all tests." OFF)
+option(release_type "Set the type of the releas (Debug/Release)." Release)
+
+
 ## Use modern C++!
 set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_BUILD_TYPE Release)
+set(CMAKE_BUILD_TYPE ${release_type})
 
 find_package(PkgConfig REQUIRED)
 
 message(" - Build type is set to ${CMAKE_BUILD_TYPE}")
 
-add_subdirectory(
-    src
-)
+## Add folders with app and tests
+##
+add_subdirectory(src)
 
+if (test)
+    add_subdirectory(libs/googletest)
+    add_subdirectory(tests)
+endif()

googletest @ 8b4817e3

+Subproject commit 8b4817e3df3746a20502a84580f661ac448821be

tests/CMakeLists.txt

+
+enable_testing()
+include_directories(${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
+add_executable(runUnitTests test_qpong.cpp)
+target_link_libraries(runUnitTests gtest gtest_main)
+target_link_libraries(runUnitTests qpong)
+add_test(NAME a-test COMMAND runUnitTests)

tests/test_qpong.cpp

+#include <iostream>
+#include "gtest/gtest.h"
+
+
+/// @brief A simple function to test
+///
+int addInts(int a, int b)
+{
+    return a + b;
+}
+
+
+TEST(addInts, addNumbers)
+{
+    int a{ 1 };
+    int b{ 3 };
+
+    EXPECT_EQ(4, addInts(a,b));
+}
+
+