On Fri, 2007-10-26 at 10:48 +0000, Duncan Coutts wrote:
So what's next...
We want to write some specifications
Spencer, Lennart, Thomas and I had a joint hacking session in which we made some progress on this issue today. Specifically we can now generate random dep graphs for use in QuickCheck tests. For example: http://haskell.org/~duncan/cabal/foo.svg We can tune the size and 'density' of these graphs. As you can see we get cycles in the graphs. We'll have to filter out cycles. Any suggestions on a simple way to do that? It's ok to depend on Data.Graph for this kind of test code. So the first testing strategy we're going for is to generate random dep graphs. From there we will write out a suitable selection of the files and run the make algorithm. We then inspect the resulting event trace and final state to check that everything worked correctly. So we'll be making the dependency generator from this random dep graph too. So this is for testing make in isolation. For the next bit of testing our rule sets for building Haskell projects we'll have to generate dep graphs that use files mentioned in our rule sets. That's probably a bit harder. We're using a trivial representation of the random dep graphs:
newtype TestDepGraph = TestDepGraph [Dep]
data Dep = Target :<= Target deriving (Eq, Show)
foo :<= bar means that we generate foo from bar So an example property might look something like:
prop_makeUpToDate :: Property prop_makeUpToDate = forall $ \graph -> let build = do mapM_ touch (files graph) make (gen graph) in allUpToDate (finalState build)
As I mentioned, the gen function will have to do its rule generation based on the random graph we generated. The new code will be in the repo shortly... darcs get http://haskell.org/~duncan/cabal/dep-experiment/ Duncan