The functions were tested with the tutorials at the conduit's README. Of course, it doesn't cover all of the uses of all of the functions, and it's not automated.
The tests of the original Haskell conduit package use hspec, which in turn depends on TypeFamilies. Unfortunately, that language extension is not supported by Frege (yet).
The functions were tested with the tutorials at the conduit's README. Of course, it doesn't cover all of the uses of all of the functions, and it's not automated.