GTest 单元测试模板

Warning

本文不是教程，只是一个模板，方便本人复制粘贴而已

部分内容参考自博客 GTest / GMock 单元测试实践手册，详细的可以进博客学习

项目架构

假定项目的结构为：

Terminal window

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.
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├── build
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├── CMakeLists.txt
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├── Makefile
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├── README.md
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├── scripts
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├── src
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│   └── main.cpp
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└── tests
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    ├── CMakeLists.txt
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    └── tree.cpp

我们在 tests 中写单元测试，其中，一个 cpp 文件是一个大的单元测试

CMakeLists

我们在根目录的 CMakeLists.txt 的最后写上：

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...
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enable_testing()
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add_subdirectory(tests)

然后，在 tests/CMakeLists.txt 中写上：

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# Find required packages
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find_package(GTest REQUIRED)
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# Find all test source files
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file(GLOB TEST_SOURCES "*.cpp")
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# Create Library to Test
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...
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# For each test file, create a separate test executable
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foreach(TEST_SOURCE ${TEST_SOURCES})
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    get_filename_component(TEST_NAME ${TEST_SOURCE} NAME_WE)
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    add_executable(${TEST_NAME}_test ${TEST_SOURCE})
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    target_link_libraries(${TEST_NAME}_test
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      ${CUSTOM_LIBS}
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    )
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    # Add to CTest
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    add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME}_test)
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endforeach()

然后我们在根目录的 Makefile 下创建一个 test 目标：

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.PHONY: all build test
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# Default target
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all: build
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build:
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  @cmake -S . -B build
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  @cmake --build build -- -j$(shell nproc)
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# Run tests
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test: build
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  @cd build && ctest --output-on-failure
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# Run specific test by name
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test-%: build
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  @cd build && ctest -R $* --output-on-failure
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# Run tests with verbose output
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test-verbose: build
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  @cd build && ctest -V

这样，我们写完测试后即可通过运行

Terminal window

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make test

做单元测试

单元测试模板

这里我们通过 TestFixture 的方式来写单元测试，例如现在我有一个二叉树 PartitionTree，那么我们的单元测试如下：

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#include "partition_tree.hpp"
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#include <gtest/gtest.h>
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#include <sys/types.h>
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class PartitionTreeTest : public ::testing::Test {
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public:
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  PartitionTree tree;
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  std::string debug_message() {
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    std::stringstream ss;
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    return tree.to_string();
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  }
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protected:
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  void SetUp() override { tree.init(n_threads); }
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  void TearDown() override { tree.clear(); }
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  std::vector<int> assumptions = {1, 2, 3, 4, 5, 6, 7};
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  int depth = 3;
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  int n_threads = 8;
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};
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TEST_F(PartitionTreeTest, BasicInitializationBinMode) {
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  tree.init_with_binary(assumptions, depth, n_threads);
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  EXPECT_TRUE(tree.m_root != nullptr);
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  for (int i = 0; i < n_threads; i++) {
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    EXPECT_TRUE((int)tree.collect_pre_decision(i).size() == depth);
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  }
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  EXPECT_TRUE(
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      reinterpret_cast<Node *>(tree.m_wid_to_addr[0])->m_parent->m_split_lit ==
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      3);
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}
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TEST_F(PartitionTreeTest, BasicInitializationScaMode) {
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  tree.init_with_scattering(assumptions, 2);
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  auto w0_pd = tree.collect_pre_decision(0);
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  auto w1_pd = tree.collect_pre_decision(1);
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  EXPECT_TRUE(w0_pd.size() == 1 && w1_pd.size() == 1);
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  EXPECT_TRUE(w0_pd[0] == 1 && w1_pd[0] == -1) << debug_message();
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}
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TEST_F(PartitionTreeTest, BasicUpdateInBinMode) {
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  tree.init_with_binary(assumptions, depth, n_threads);
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  u_int64_t w1_addr = tree.m_wid_to_addr[1];
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  tree.update(0, 1, 9);
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  u_int64_t w1_addr_new = tree.m_wid_to_addr[1];
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  EXPECT_TRUE(w1_addr != w1_addr_new);
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  auto w0_pd = tree.collect_pre_decision(0);
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  auto w1_pd = tree.collect_pre_decision(1);
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  EXPECT_TRUE(w0_pd.size() == 4);
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  EXPECT_TRUE(w1_pd.size() == 4);
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  EXPECT_TRUE(w0_pd.back() == -9);
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  EXPECT_TRUE(w1_pd.back() == 9);
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}
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TEST_F(PartitionTreeTest, BasicUpdateInScaMode) {
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  tree.init_with_scattering(assumptions, n_threads);
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  u_int64_t w1_addr = tree.m_wid_to_addr[1];
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  tree.update(0, 1, 9);
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  u_int64_t w1_addr_new = tree.m_wid_to_addr[1];
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  EXPECT_TRUE(w1_addr != w1_addr_new) << debug_message();
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  auto w0_pd = tree.collect_pre_decision(0);
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  auto w1_pd = tree.collect_pre_decision(1);
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  EXPECT_TRUE(w0_pd.size() == 2);
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  EXPECT_TRUE(w1_pd.size() == 2);
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  EXPECT_TRUE(w0_pd.back() == -9);
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  EXPECT_TRUE(w1_pd.back() == 9);
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}
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int main(int argc, char **argv) {
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  ::testing::InitGoogleTest(&argc, argv);
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  return RUN_ALL_TESTS();
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}

这个文件是一个大测试点，其中，每个小测试点 Test Case 通过 TEST_F(TestFixure, TestCaseName) 实现，我们这么写的原因是为了可以共享一些测试变量，也可以少写一些代码（

Tip

继承自 Test 的类，其 SetUp 函数会在每个 Test Case 执行之前被调用，而 TearDown 函数则会在每个 Test Case 执行之后被调用。