Unit tests will be automatically compiled if dependencies were met in ./configure
and tests weren't explicitly disabled.
After configuring, they can be run with make check.
To run the litecoind tests manually, launch src/test/test_litecoin. To recompile
after a test file was modified, run make and then run the test again. If you
modify a non-test file, use make -C src/test to recompile only what's needed
to run the litecoind tests.
To add more litecoind tests, add BOOST_AUTO_TEST_CASE functions to the existing
.cpp files in the test/ directory or add new .cpp files that
implement new BOOST_AUTO_TEST_SUITE sections.
To run the litecoin-qt tests manually, launch src/qt/test/test_litecoin-qt
To add more litecoin-qt tests, add them to the src/qt/test/ directory and
the src/qt/test/test_main.cpp file.
test_litecoin has some built-in command-line arguments; for example, to run just the getarg_tests verbosely:
test_litecoin --log_level=all --run_test=getarg_tests
... or to run just the doubledash test:
test_litecoin --run_test=getarg_tests/doubledash
Run test_litecoin --help for the full list.
The sources in this directory are unit test cases. Boost includes a unit testing framework, and since litecoin already uses boost, it makes sense to simply use this framework rather than require developers to configure some other framework (we want as few impediments to creating unit tests as possible).
The build system is setup to compile an executable called "test_litecoin" that runs all of the unit tests. The main source file is called test_bitcoin.cpp, which simply includes other files that contain the actual unit tests (outside of a couple required preprocessor directives). The pattern is to create one test file for each class or source file for which you want to create unit tests. The file naming convention is "<source_filename>_tests.cpp" and such files should wrap their tests in a test suite called "<source_filename>_tests". For an examples of this pattern, examine uint160_tests.cpp and uint256_tests.cpp.
Add the source files to /src/Makefile.test.include to add them to the build.
For further reading, I found the following website to be helpful in explaining how the boost unit test framework works: http://www.alittlemadness.com/2009/03/31/c-unit-testing-with-boosttest/.