Hi
This gives a list of properties, which are automatically extracted from the documentation, and checked using QuickCheck. All the tool is in the repo. If anyone wanted to generalise the code in there, it would be handy!
Neil, your extractor looks cool, but I wonder how it'll work with modules like Data.Set whose (commented out) tests define some Arbitrary instances and some helper functions in addition to the actual properties. My first inclination would have been to define the properties in code, perhaps "#ifdef TESTING"ed out, and try to teach Haddock to pull them into the documentation. But yours is definitely simpler and probably worth pursuing until it obviously stops working.
FilePath also has that issue, I do: module FilePath( #ifdef TESTING properties and instances for testing #endif ) where Then I just define TESTING when running the test. This has the advantage that the tests at least always compile, even as I make other changes. In reality, FilePath only requires a couple of things (the drive properties) to be exported for testing but not for real use. I don't see much complication in extending my approach. In fact, I suspect that my FilePath test extractor is overly complex, since it allows: Windows: property Posix: property property For Windows properties it added System.FilePath.Windows.functions, ditto for Posix, and for normal ones it generates the test twice, once with Windows and once with Posix. It also detects if a property has any free variables, and if not changes it to a single assertion, rather than a quickcheck property. I think it is very handy, and integrating it with Cabal and removing the special cases that FilePath requires is probably well worth the effort! I would certainly like such a tool... Thanks Neil