googletest是一个用来写C++单元测试的框架，它是跨平台的，可应用在windows、linux、Mac等OS平台上。下面，我来说明如何使用最新的1.7版本gtest写自己的单元测试。
本文包括以下几部分：1、获取并编译googletest（以下简称为gtest）；2、如何编写单元测试用例；3、如何执行单元测试。4、google test内部是如何执行我们的单元测试用例的。
1. 获取并编译gtest
gtest试图跨平台，理论上，它就应该提供多个版本的binary包。但事实上，gtest只提供源码和相应平台的编译方式，这是为什么呢？google的解释是，我们在编译出gtest时，有些独特的工程很可能希望在编译时加许多flag，把编译的过程下放给用户，可以让用户更灵活的处理。这个仁者见仁吧，反正也是免费的BSD权限。
源码的获取地址：http://code.google.com/p/googletest/downloads/list
目前gtest提供的是1.7.0版本，我们看看与以往版本1.6.0的区别：
Changes for 1.7.0: * New feature: death tests are supported on OpenBSD and in iOS simulator now. * New feature: Google Test now implements a protocol to allow a test runner to detect that a test program has exited prematurely and report it as a failure (before it would be falsely reported as a success if the exit code is 0). * New feature: Test::RecordProperty() can now be used outside of the lifespan of a test method, in which case it will be attributed to the current test case or the test program in the XML report. * New feature (potentially breaking): --gtest_list_tests now prints the type parameters and value parameters for each test. * Improvement: char pointers and char arrays are now escaped properly in failure messages. * Improvement: failure summary in XML reports now includes file and line information. * Improvement: the <testsuites> XML element now has a timestamp attribute. * Improvement: When --gtest_filter is specified, XML report now doesn't contain information about tests that are filtered out. * Fixed the bug where long --gtest_filter flag values are truncated in death tests. * Potentially breaking change: RUN_ALL_TESTS() is now implemented as a function instead of a macro in order to work better with Clang. * Compatibility fixes with C++ 11 and various platforms. * Bug/warning fixes.
那么怎么编译呢？
先进入gtest目录（解压gtest.zip包过程就不说了），执行以下两行命令：
- g++ -I./include -I./ -c ./src/gtest-all.cc
- ar -rv libgtest.a gtest-all.o
之后，生成了libgtest.a，这个就是我们要的东东了。以后写自己的单元测试，就需要libgtest.a和gtest目录下的include目录，所以，这1文件1目录我们需要拷贝到自己的工程中。
编译完成后怎么验证是否成功了呢？
- cd ${GTEST_DIR}/make
- make
- ./sample1_unittest
如果看到下面的输出，就说明成功了。
Running main() from gtest_main.cc [==========] Running 6 tests from 2 test cases. [----------] Global test environment set-up. [----------] 3 tests from FactorialTest [ RUN ] FactorialTest.Negative [ OK ] FactorialTest.Negative (0 ms) [ RUN ] FactorialTest.Zero [ OK ] FactorialTest.Zero (0 ms) [ RUN ] FactorialTest.Positive [ OK ] FactorialTest.Positive (0 ms) [----------] 3 tests from FactorialTest (0 ms total) [----------] 3 tests from IsPrimeTest [ RUN ] IsPrimeTest.Negative [ OK ] IsPrimeTest.Negative (0 ms) [ RUN ] IsPrimeTest.Trivial [ OK ] IsPrimeTest.Trivial (0 ms) [ RUN ] IsPrimeTest.Positive [ OK ] IsPrimeTest.Positive (0 ms) [----------] 3 tests from IsPrimeTest (1 ms total) [----------] Global test environment tear-down [==========] 6 tests from 2 test cases ran. (1 ms total) [ PASSED ] 6 tests.
2、如何编写单元测试用例
测试实例等具体做了再添加。
文章参考链接：http://blog.csdn.net/russell_tao/article/details/7333226
