// 下载
git clone https://github.com/google/googletest
// 现在官方已经把 gtest 和 gmock 一起维护，所以这个 git 仓库还包含了 gmock。
// 编译、安装
cd googletest-main
mkdir build install
cd build
cmake -DCMAKE_INSTALL_PREFIX=../install
make -j
make install

TEST(MyTestSuite, MyTest) {
  // 测试代码
}

TEST(MyTestSuite, MyTest) {
  int a = 1;
  int b = 2;
  ASSERT_TRUE(a < b);
  ASSERT_EQ(a + b, 3);
}

TEST(MyTestSuite, MyTest) {
  int a = 1;
  int b = 2;
  EXPECT_TRUE(a < b);
  EXPECT_EQ(a + b, 3);
}

class MyTestSuite : public ::testing::Test {
 protected:
  void SetUp() override {
    // 初始化代码
  }
  void TearDown() override {
    // 清理代码
  }
};
TEST_F(MyTestSuite, MyTest) {
  // 测试代码
}

class MyTestSuite : public ::testing::TestWithParam<int> {
};
TEST_P(MyTestSuite, MyTest) {
  int input = GetParam();
  // 测试代码
}
INSTANTIATE_TEST_SUITE_P(MyTestSuiteInstantiationName, MyTestSuite, ::testing::Values(1, 2, 3));

TEST(MyTestSuite, MyTest) {
  std::vector<int> v;
  EXPECT_THROW(v.at(0), std::out_of_range);
}

#include <limits.h>
#include "sample1.h"
#include "gtest/gtest.h"
// Tests factorial of negative numbers.
TEST(FactorialTest, Negative) {
  // This test is named "Negative", and belongs to the "FactorialTest"
  // test case.
  EXPECT_EQ(1, Factorial(-5));
  EXPECT_EQ(1, Factorial(-1));
  EXPECT_GT(Factorial(-10), 0);
}
...
TEST(IsPrimeTest, Positive) {
  EXPECT_FALSE(IsPrime(4));
  EXPECT_TRUE(IsPrime(5));
  EXPECT_FALSE(IsPrime(6));
  EXPECT_TRUE(IsPrime(23));
}

// CMakeLists.txt
cmake_minimum_required(VERSION 3.10)
project(GTEST_USAGE)
set(CMAKE_CXX_COMPILE_FLAGS "std=c++11")
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/install/include)
file(GLOB CPP_FILES ${CMAKE_CURRENT_SOURCE_DIR}/*.c*)
link_directories(${CMAKE_CURRENT_SOURCE_DIR}/install/lib)
add_executable(GTEST_USAGE ${CPP_FILES})
target_link_libraries(GTEST_USAGE 
gtest
)

// main.cpp
#include <gtest/gtest.h>
#include<numeric>
int main(int argc, char **argv)
{
  testing::InitGoogleTest(&argc, argv)
  return 0;
}

// Copyright 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// A sample program demonstrating using Google C++ testing framework.
#include "sample4.h"
#include <stdio.h>
// Returns the current counter value, and increments it.
int Counter::Increment() { return counter_++; }
// Returns the current counter value, and decrements it.
// counter can not be less than 0, return 0 in this case
int Counter::Decrement() {
  if (counter_ == 0) {
    return counter_;
  } else {
    return counter_--;
  }
}
// Prints the current counter value to STDOUT.
void Counter::Print() const { printf("%d", counter_); }

// Copyright 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// A sample program demonstrating using Google C++ testing framework.
#ifndef GOOGLETEST_SAMPLES_SAMPLE4_H_
#define GOOGLETEST_SAMPLES_SAMPLE4_H_
// A simple monotonic counter.
class Counter {
 private:
  int counter_;
 public:
  // Creates a counter that starts at 0.
  Counter() : counter_(0) {}
  // Returns the current counter value, and increments it.
  int Increment();
  // Returns the current counter value, and decrements it.
  int Decrement();
  // Prints the current counter value to STDOUT.
  void Print() const;
};
#endif  // GOOGLETEST_SAMPLES_SAMPLE4_H_

// Copyright 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "sample4.h"
#include "gtest/gtest.h"
namespace {
// Tests the Increment() method.
TEST(Counter, Increment) {
  Counter c;
  // Test that counter 0 returns 0
  EXPECT_EQ(0, c.Decrement());
  // EXPECT_EQ() evaluates its arguments exactly once, so they
  // can have side effects.
  EXPECT_EQ(0, c.Increment());
  EXPECT_EQ(1, c.Increment());
  EXPECT_EQ(2, c.Increment());
  EXPECT_EQ(3, c.Decrement());
}
}  // namespace