add gtest and sample test

Author: hacksdump

CMakeLists.txt

@@ -3,4 +3,47 @@ project(gtest_coverage)
 
 set(CMAKE_CXX_STANDARD 20)
 
-add_executable(gtest_coverage main.cpp src/testsubject.cpp)
+# Reference: https://github.com/google/googletest/tree/master/googletest#incorporating-into-an-existing-cmake-project
+# Download and unpack googletest at configure time
+configure_file(CMakeLists.txt.in googletest-download/CMakeLists.txt)
+execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
+        RESULT_VARIABLE result
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download)
+if (result)
+    message(FATAL_ERROR "CMake step for googletest failed: ${result}")
+endif ()
+execute_process(COMMAND ${CMAKE_COMMAND} --build .
+        RESULT_VARIABLE result
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download)
+if (result)
+    message(FATAL_ERROR "Build step for googletest failed: ${result}")
+endif ()
+
+# Prevent overriding the parent project's compiler/linker
+# settings on Windows
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+
+# Add googletest directly to our build. This defines
+# the gtest and gtest_main targets.
+add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
+        ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
+        EXCLUDE_FROM_ALL)
+
+# The gtest/gtest_main targets carry header search path
+# dependencies automatically when using CMake 2.8.11 or
+# later. Otherwise we have to add them here ourselves.
+if (CMAKE_VERSION VERSION_LESS 2.8.11)
+    include_directories("${gtest_SOURCE_DIR}/include")
+endif ()
+
+# Now simply link against gtest or gtest_main as needed.
+include_directories(cmake-build-debug/googletest-src/googlemock/include)
+include_directories(cmake-build-debug/googletest-src/googletest/include)
+
+set(SOURCE_FILES src/testsubject.cpp)
+add_executable(main main.cpp ${SOURCE_FILES})
+
+set(TEST_FILES test/tester.cpp)
+add_executable(test ${TEST_FILES} ${SOURCE_FILES})
+
+target_link_libraries(test gtest gtest_main)

CMakeLists.txt.in

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 2.8.2)
+
+project(googletest-download NONE)
+
+include(ExternalProject)
+ExternalProject_Add(googletest
+  GIT_REPOSITORY    https://github.com/google/googletest.git
+  GIT_TAG           master
+  SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
+  BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
+  CONFIGURE_COMMAND ""
+  BUILD_COMMAND     ""
+  INSTALL_COMMAND   ""
+  TEST_COMMAND      ""
+)

test/tester.cpp

@@ -0,0 +1,8 @@
+#include <gtest/gtest.h>
+
+#include "../src/testsubject.h"
+
+TEST(MathTest, Square) {
+    ASSERT_EQ(TestSubject::square(2), 4);
+    ASSERT_EQ(TestSubject::square(3), 9);
+}