On Tue, Oct 26, 2010 at 11:11 AM, Dupont Corentin
Hello again café,
I have a command line program that takes input from various handles (actually network sockets) like this:
s <- hGetLine h etc.
I'd like to unit test this. How can I do? I'd like to inject data on the handle so that all the input chain is tested.
I haven't tested it yet, but this "mock handle" will eventually work in GHC 7: http://hackage.haskell.org/trac/ghc/attachment/ticket/4144/ByteStringHandle.... At least, the bug report about how it didn't work has now been closed :-) I don't remember which operations worked and which didn't - getChar would work, but getContents would fail. The others have great advice, that you should try to isolate the logic of your code from IO for precisely this reason - so it is easily testable. Antoine