`tests` is the root level directory for SDK testing.

Unit and integration tests are contained within the `unit` and `integration`
directories, respectively. Note that unit tests do NOT do I/O and are very fast
whereas integration tests typically require I/O, are slower, and harder to maintain.

Unit and integration tests require the google test framework:
https://github.com/google/googletest

Building gtest and the tests itself depends very much on your OS and your build
system of choice. We currently support autotools, QMake, and CMake.

You can run all tests or just a subset of the tests by supplying a filter to the
test executable, e.g., `./test_unit --gtest_filter=Crypto*`

Unit and integration tests are organized in such a way that the filename
should match the name of the contained test suite. A single test file should
only contain a single test suite. E.g., `Crypto_test.cpp` should only contain
tests like `TEST(Crypto, blahblah)`. This makes test discovery more efficient.
Any testing framework code should live inside the `mt` namespace (= mega testing).

The `tool` directory contains standalone test applications that must be run manually.

The `python` directory contains work-in-progress system tests written in python.