Tests are defined in src/tests/black-box/CMakeLists.txt. Each test is split into two steps: creating an audio file, and comparing that audio file to the previous (working) audio file.
When an audio file is specified as an “answer” file,
audioCompare phasevoder.au ../output/right-phasevocoder.au
we attempt to match the files approximately, to avoid rounding mismatches on different operating systems. Each sample must be very close to the corresponding sample in the answer file, but they need not be exact.