Merge branch 'ghc-7.6' of http://darcs.haskell.org/haddock into ghc-7.6

1 files changed, 126 insertions, 0 deletions

diff --git a/tests/nanospec/Test/Hspec.hs b/tests/nanospec/Test/Hspec.hs
new file mode 100644
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+++ b/tests/nanospec/Test/Hspec.hs
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+{-# LANGUAGE DeriveDataTypeable, CPP #-}
+-- | A lightweight implementation of a subset of Hspec's API.
+module Test.Hspec (
+-- * Types
+  SpecM
+, Spec
+
+-- * Defining a spec
+, describe
+, context
+, it
+
+-- ** Setting expectations
+, Expectation
+, expect
+, shouldBe
+, shouldReturn
+
+-- * Running a spec
+, hspec
+) where
+
+import           Control.Applicative
+import           Control.Monad
+import           Data.Monoid
+import           Data.List (intercalate)
+import           Data.Typeable
+import qualified Control.Exception as E
+import           System.Exit
+
+-- a writer monad
+data SpecM a = SpecM a [SpecTree]
+
+add :: SpecTree -> SpecM ()
+add s = SpecM () [s]
+
+instance Monad SpecM where
+  return a             = SpecM a []
+  SpecM a xs >>= f = case f a of
+    SpecM b ys -> SpecM b (xs ++ ys)
+
+data SpecTree = SpecGroup String Spec
+              | SpecExample String (IO Result)
+
+data Result = Success | Failure String
+  deriving (Eq, Show)
+
+type Spec = SpecM ()
+
+describe :: String -> Spec -> Spec
+describe label = add . SpecGroup label
+
+context :: String -> Spec -> Spec
+context = describe
+
+it :: String -> Expectation -> Spec
+it label = add . SpecExample label . evaluateExpectation
+
+-- | Summary of a test run.
+data Summary = Summary Int Int
+
+instance Monoid Summary where
+  mempty = Summary 0 0
+  (Summary x1 x2) `mappend` (Summary y1 y2) = Summary (x1 + y1) (x2 + y2)
+
+runSpec :: Spec -> IO Summary
+runSpec = runForrest []
+  where
+    runForrest :: [String] -> Spec -> IO Summary
+    runForrest labels (SpecM () xs) = mconcat <$> mapM (runTree labels) xs
+
+    runTree :: [String] -> SpecTree -> IO Summary
+    runTree labels spec = case spec of
+      SpecExample label x -> do
+        putStr $ "/" ++ (intercalate "/" . reverse) (label:labels) ++ "/ "
+        r <- x
+        case r of
+          Success   -> do
+            putStrLn "OK"
+            return (Summary 1 0)
+          Failure err -> do
+            putStrLn "FAILED"
+            putStrLn err
+            return (Summary 1 1)
+      SpecGroup label xs  -> do
+        runForrest (label:labels) xs
+
+hspec :: Spec -> IO ()
+hspec spec = do
+  Summary total failures <- runSpec spec
+  putStrLn (show total ++ " example(s), " ++ show failures ++ " failure(s)")
+  when (failures /= 0) exitFailure
+
+type Expectation = IO ()
+
+infix 1 `shouldBe`, `shouldReturn`
+
+shouldBe :: (Show a, Eq a) => a -> a -> Expectation
+actual `shouldBe` expected =
+  expect ("expected: " ++ show expected ++ "\n but got: " ++ show actual) (actual == expected)
+
+shouldReturn :: (Show a, Eq a) => IO a -> a -> Expectation
+action `shouldReturn` expected = action >>= (`shouldBe` expected)
+
+expect :: String -> Bool -> Expectation
+expect label f
+  | f         = return ()
+  | otherwise = E.throwIO (ExpectationFailure label)
+
+data ExpectationFailure = ExpectationFailure String
+  deriving (Show, Eq, Typeable)
+
+instance E.Exception ExpectationFailure
+
+evaluateExpectation :: Expectation -> IO Result
+evaluateExpectation action = (action >> return Success)
+  `E.catches` [
+  -- Re-throw AsyncException, otherwise execution will not terminate on SIGINT
+  -- (ctrl-c).  All AsyncExceptions are re-thrown (not just UserInterrupt)
+  -- because all of them indicate severe conditions and should not occur during
+  -- normal operation.
+    E.Handler $ \e -> E.throw (e :: E.AsyncException)
+
+  , E.Handler $ \(ExpectationFailure err) -> return (Failure err)
+  , E.Handler $ \e -> (return . Failure) ("*** Exception: " ++ show (e :: E.SomeException))
+  ]