some additions to testing utilities in preparation for part2

exercises/Mooc/LimitedPrelude.hs

@@ -1 +1 @@
-module Mooc.LimitedPrelude (Int,Integer,Bool(..),Ordering(..),Eq(..),Ord(..),Num(..),Maybe(..),otherwise)  where
+module Mooc.LimitedPrelude (Int,Integer,Bool(..),Ordering(..),Eq(..),Ord(..),Num(..),Maybe(..),otherwise,undefined)  where

exercises/Mooc/Test.hs

@@ -2,7 +2,7 @@
 
 module Mooc.Test where
 
-import Control.Exception (evaluate,SomeException,fromException)
+import Control.Exception (try,evaluate,SomeException,fromException)
 import Control.Monad
 import Control.DeepSeq (deepseq)
 import Data.Foldable
@@ -54,6 +54,10 @@ forAllShrink_ gen = forAllShrinkBlind gen shrink
 forAll_ :: Arbitrary a => (a -> Property) -> Property
 forAll_ = forAllShrink_ arbitrary
 
+-- nondeterministic conjoin
+conjoin' :: Testable prop => [prop] -> Property
+conjoin' ps = property $ elements ps
+
 -- timeouts for evaluation
 
 timedMillis = 500
@@ -64,6 +68,18 @@ timed val k = monadicIO $ do
     Nothing -> return $ counterexample' ("  didn't return in "++show timedMillis++"ms") $ False
     Just v -> return $ k v
 
+-- exceptions
+
+eval :: a -> PropertyM IO (Either SomeException a)
+eval x = run $ try $ evaluate x
+
+isFail :: Either SomeException a -> Property
+isFail (Left e) = property True
+isFail (Right _) = counterexample "  should fail" False
+
+shouldFail :: a -> Property
+shouldFail x = monadicIO $ fmap isFail $ eval x
+
 -- handling TODO excercises
 
 isTodo :: SomeException -> Bool
@@ -86,10 +102,10 @@ instance Monoid Outcome where
 
 quietArgs = stdArgs {chatty=False}
 
-timeLimit = 10 * 1000 * 1000 -- 10 seconds in microseconds
+globalTimeLimit = 10 * 1000 * 1000 -- 10 seconds in microseconds
 
 myCheck :: Testable prop => prop -> IO Outcome
-myCheck prop = quickCheckWithResult quietArgs (within timeLimit prop) >>= interpret
+myCheck prop = quickCheckWithResult quietArgs (within globalTimeLimit prop) >>= interpret
   where interpret res
           | resultIsTodo res = return Todo
           | isSuccess res = return Pass

exercises/Mooc/Th.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE TemplateHaskell, DeriveLift, StandaloneDeriving #-}
 
-module Mooc.Th (testing, testing',
+module Mooc.Th (testing, testing', timeLimit,
                 isDefined, withDefined, hasType, importsOnly, show',
                 reifyType, DataType(..), FieldType(..), Constructor(..),
                 withInstance, withInstance1, classContains, defineInstance)
@@ -199,6 +199,7 @@ unqualify (UInfixE left op right) = UInfixE (unqualify left) (unqualify op) (unq
 unqualify (LitE l) = LitE l
 unqualify (TupE exps) = TupE (map unqualify exps)
 unqualify (ListE exps) = ListE (map unqualify exps)
+unqualify (ArithSeqE (FromR x)) = ArithSeqE (FromR (unqualify x))
 unqualify x = error $ "Unsupported: " ++ show x
 
 testing' :: Q Exp -> Q Exp