A black box test in the terminology of the HTF consists of a driver program that is run in various input files. For each input file, the HTF checks that the driver program exits with the correct exit code and that it produces the expected output.
Documentation
type Diff = Maybe FilePath -> String -> IO (Maybe String)Source
The type of a function comparing the content of a file
against a string, similar to the unix tool diff
.
The first parameter is the name of the file containing the
expected output. If this parameter is Nothing
, then no output
is expected. The second parameter is the actual output produced.
If the result is Nothing
then no difference was found.
Otherwise, a Just
value contains a string explaining the
different.