Googletest
From Apache OpenOffice Wiki
googletest is Google's framework for writing C++ tests (unit tests) on a variety of platforms. The intention is to use this test framework as replacement for cppunit that is license incompatible with Apache.
What googletest (gtest) is and a general introduction how to use it can be found on the googletest webpage. The documentation is very useful and provide some good examples, starting with a primer up to more comprehensive documentation for complex test.