saddle-points: Rewrite tests to use hspec with fail-fast.

exercises/saddle-points/package.yaml

@@ -18,4 +18,4 @@ tests:
     source-dirs: test
     dependencies:
       - saddle-points
-      - HUnit
+      - hspec

exercises/saddle-points/test/Tests.hs

@@ -1,48 +1,47 @@
-import Test.HUnit (Assertion, (@=?), runTestTT, Test(..), Counts(..))
-import System.Exit (ExitCode(..), exitWith)
-import Matrix (saddlePoints)
-import Data.Array (listArray)
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
 
-exitProperly :: IO Counts -> IO ()
-exitProperly m = do
-  counts <- m
-  exitWith $ if failures counts /= 0 || errors counts /= 0 then ExitFailure 1 else ExitSuccess
+import Data.Array        (listArray)
+import Data.Foldable     (for_)
+import Test.Hspec        (Spec, describe, it, shouldBe)
+import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
 
-testCase :: String -> Assertion -> Test
-testCase label assertion = TestLabel label (TestCase assertion)
+import Matrix (saddlePoints)
 
 main :: IO ()
-main = exitProperly $ runTestTT $ TestList
-       [ TestList matrixTests ]
-
-matrixTests :: [Test]
-matrixTests =
-  [ testCase "Example from README" $ do
-    let matrix = listArray ((0, 0), (2, 2))
-                 [ 9, 8, 7
-                 , 5, 3, 2
-                 , 6, 6, 7 ]
-    [(1, 0)] @=? saddlePoints matrix
-  , testCase "no saddle point" $ do
-    let matrix = listArray ((0, 0), (1, 1))
-                 [ 2, 1
-                 , 1, 2 ]
-    [] @=? saddlePoints matrix
-  , testCase "a saddle point" $ do
-    let matrix = listArray ((0, 0), (1, 1))
-                 [ 1, 2
-                 , 3, 4 ]
-    [(0, 1)] @=? saddlePoints matrix
-  , testCase "another saddle point" $ do
-    let matrix = listArray ((0, 0), (2, 4))
-                 [ 18,  3, 39, 19,  91
-                 , 38, 10,  8, 77, 320
-                 ,  3,  4,  8,  6,   7 ]
-    [(2, 2)] @=? saddlePoints matrix
-  , testCase "multiple saddle points" $ do
-    let matrix = listArray ((0, 0), (2, 2))
-                 [ 4, 5, 4
-                 , 3, 5, 5
-                 , 1, 5, 4 ]
-    [(0, 1), (1, 1), (2, 1)] @=? saddlePoints matrix
-  ]
+main = hspecWith defaultConfig {configFastFail = True} specs
+
+specs :: Spec
+specs = describe "saddle-points" $
+          describe "saddlePoints" $ for_ cases test
+  where
+
+    test (description, xss, expected) = it description assertion
+      where
+        assertion = saddlePoints matrix `shouldBe` expected
+        rows      = length xss
+        columns   = length $ head xss
+        matrix    = listArray ((0, 0), (rows - 1, columns - 1)) (concat xss)
+
+    -- As of 2016-09-12, there was no reference file
+    -- for the test cases in `exercism/x-common`.
+
+    cases = [ ("Example from README", [ [9, 8, 7]
+                                      , [5, 3, 2]
+                                      , [6, 6, 7] ], [(1, 0)] )
+
+            , ( "no saddle point", [ [2, 1]
+                                   , [1, 2] ], [] )
+
+            , ( "a saddle point", [ [1, 2]
+                                  , [3, 4] ], [(0, 1)] )
+
+            , ( "another saddle point", [ [18,  3, 39, 19,  91]
+                                        , [38, 10,  8, 77, 320]
+                                        , [ 3,  4,  8,  6,   7] ], [(2, 2)] )
+
+            , ("multiple saddle points", [ [4, 5, 4]
+                                         , [3, 5, 5]
+                                         , [1, 5, 4] ], [ (0, 1)
+                                                        , (1, 1)
+                                                        , (2, 1) ] )
+            ]