Unit tests are powered by PHPUnit. They test one and only one PHP class, mocking/stubbing any dependencies that class might have.
Unit folder meets some rules:
If there is a hard-coded dependency such as a singleton pattern being used or a static call, this class cannot be unit tested and should be tested using integration tests.
We use the following stack:
camelCasenames for test function names.
testGetPrice(no idea what such a test is supposed to do)