Set up gtest

.gitignore

@@ -269,6 +269,7 @@ _Pvt_Extensions
 *.app
 /windows/LightGBM.VC.db
 lightgbm
+/testlightgbm
 
 # Created by https://www.gitignore.io/api/python
 

CMakeLists.txt

@@ -7,10 +7,11 @@ OPTION(USE_TIMETAG "Set to ON to output time costs" OFF)
 OPTION(USE_CUDA "Enable CUDA-accelerated training (EXPERIMENTAL)" OFF)
 OPTION(USE_DEBUG "Set to ON for Debug mode" OFF)
 OPTION(USE_SANITIZER "Use santizer flags" OFF)
-option(SANITIZER_PATH "Path to sanitizer libs")
-set(ENABLED_SANITIZERS "address" "leak" "undefined" CACHE STRING
+OPTION(SANITIZER_PATH "Path to sanitizer libs")
+SET(ENABLED_SANITIZERS "address" "leak" "undefined" CACHE STRING
   "Semicolon separated list of sanitizer names. E.g 'address;leak'. Supported sanitizers are
 address, leak, undefined and thread.")
+OPTION(BUILD_CPP_TEST "Build C++ tests with Google Test" OFF)
 OPTION(BUILD_STATIC_LIB "Build static library" OFF)
 OPTION(__BUILD_FOR_R "Set to ON if building lib_lightgbm for use with the R package" OFF)
 OPTION(__INTEGRATE_OPENCL "Set to ON if building LightGBM with the OpenCL ICD Loader and its dependencies included" OFF)
@@ -464,6 +465,25 @@ if(__BUILD_FOR_R)
   endif(MSVC)
 endif(__BUILD_FOR_R)
 
+#-- Google C++ tests
+if(BUILD_CPP_TEST)
+  find_package(GTest CONFIG)
+  if(NOT GTEST_FOUND)
+    message(STATUS "Did not find Google Test in the system root. Fetching Google Test now...")
+    include(FetchContent)
+    FetchContent_Declare(
+      googletest
+      GIT_REPOSITORY https://github.com/google/googletest.git
+      GIT_TAG        release-1.10.0
+    )
+    FetchContent_MakeAvailable(googletest)
+    add_library(GTest::GTest ALIAS gtest)
+  endif()
+  file(GLOB CPP_TEST_SOURCES tests/cpp_test/*.cpp)
+  add_executable(testlightgbm ${CPP_TEST_SOURCES} ${SOURCES})
+  target_link_libraries(testlightgbm PRIVATE GTest::GTest)
+endif()
+
 install(TARGETS lightgbm _lightgbm
         RUNTIME DESTINATION ${CMAKE_INSTALL_PREFIX}/bin
         LIBRARY DESTINATION ${CMAKE_INSTALL_PREFIX}/lib

tests/cpp_test/test_main.cpp

@@ -0,0 +1,11 @@
+/*!
+ * Copyright (c) 2020 Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
+#include <gtest/gtest.h>
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  testing::FLAGS_gtest_death_test_style = "threadsafe";
+  return RUN_ALL_TESTS();
+}