Unit tests are implemented using the Google's C++ test framework.
The tests source files are located under the tests directory as test_*.cpp.
To build and test vt-tv use the build.sh script
Type build.sh --help to get started.
You might want also directly run the tests from the build:
{VT_TV_BUILD_DIR}/tests/unit/AllTests
Then you can run test with some google test options as described at Google Test - Running Test Programs: Advanced Options