cmake-modules/AddGoogleTest.cmake

# 
#
# Downloads GTest and provides a helper macro to add tests. Add make check, as well, which
# gives output on failed tests without having to set an environment variable.
#
# Modified version from https://github.com/CLIUtils/cmake/commit/4e52e4d0bc2e9fd27171926d0b5d9f396dd8637c
# License on Notice
#
set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)

if(CMAKE_VERSION VERSION_LESS 3.11)
    set(UPDATE_DISCONNECTED_IF_AVAILABLE "UPDATE_DISCONNECTED 1")

    include(DownloadProject)
    download_project(
        PROJ                googletest
		GIT_REPOSITORY      https://github.com/google/googletest.git
		GIT_TAG             release-1.12.1
		UPDATE_DISCONNECTED 1
		QUIET
    )

    # CMake warning suppression will not be needed in version 1.9
    set(CMAKE_SUPPRESS_DEVELOPER_WARNINGS 1 CACHE BOOL "")
    add_subdirectory(${googletest_SOURCE_DIR} ${googletest_SOURCE_DIR} EXCLUDE_FROM_ALL)
    unset(CMAKE_SUPPRESS_DEVELOPER_WARNINGS)
else()
    include(FetchContent)
    FetchContent_Declare(
        googletest
        GIT_REPOSITORY      https://github.com/google/googletest.git
        GIT_TAG             release-1.12.1
        )
    FetchContent_GetProperties(googletest)
    if(NOT googletest_POPULATED)
        FetchContent_MakeAvailable(googletest)
    endif()
endif()


if(CMAKE_CONFIGURATION_TYPES)
    add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} 
        --force-new-ctest-process --output-on-failure 
        --build-config "$<CONFIGURATION>")
else()
    add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} 
        --force-new-ctest-process --output-on-failure)
endif()
set_target_properties(check PROPERTIES FOLDER "Scripts")

#include_directories(${gtest_SOURCE_DIR}/include)

# More modern way to do the last line, less messy but needs newish CMake:
#target_include_directories(gtest INTERFACE ${gtest_SOURCE_DIR}/include)


if(GOOGLE_TEST_INDIVIDUAL)
    if(NOT CMAKE_VERSION VERSION_LESS 3.9)
        include(GoogleTest)
    else()
        set(GOOGLE_TEST_INDIVIDUAL OFF)
    endif()
endif()

# Target must already exist
macro(add_gtest TESTNAME)
    target_link_libraries(${TESTNAME} PRIVATE gtest gmock gtest_main)
    
    if(GOOGLE_TEST_INDIVIDUAL)
        if(CMAKE_VERSION VERSION_LESS 3.10)
            gtest_add_tests(TARGET ${TESTNAME}
                            TEST_PREFIX "${TESTNAME}."
                            TEST_LIST TmpTestList)
            set_tests_properties(${TmpTestList} PROPERTIES FOLDER "Tests")
        else()
            gtest_discover_tests(${TESTNAME}
                TEST_PREFIX "${TESTNAME}."
                PROPERTIES FOLDER "Tests"
                DISCOVERY_TIMEOUT 600)
        endif()
    else()
        add_test(${TESTNAME} ${TESTNAME})
        set_target_properties(${TESTNAME} PROPERTIES FOLDER "Tests")
    endif()

endmacro()

mark_as_advanced(
gmock_build_tests
gtest_build_samples
gtest_build_tests
gtest_disable_pthreads
gtest_force_shared_crt
gtest_hide_internal_symbols
BUILD_GMOCK
BUILD_GTEST
)

set_target_properties(gtest gtest_main gmock gmock_main
    PROPERTIES FOLDER "Extern")