singpolyma · April 8, 2015 18:43 · Apr 8, 2015
diff --git a/TDD.hs b/TDD.hs
@@ -0,0 +1,13 @@
+module TDD (add) where
+
+import qualified Data.Text as T
+
+data ArgumentError = ArgumentError deriving (Show)
+
+add :: String -> Integer
+add s = sum $ map toI $ T.split (\d -> d == ',' || d == '\n') (T.pack s)
+
+toI :: T.Text -> Integer
+toI s = case reads (T.unpack s) of
+	((n, _) : _) -> n
+	_            -> 0
diff --git a/Test.hs b/Test.hs
@@ -0,0 +1,57 @@
+module Main (main) where
+
+import Control.Applicative
+import Test.Framework (defaultMain, testGroup, Test)
+import Test.Framework.Providers.HUnit
+import Test.Framework.Providers.QuickCheck2
+import Test.QuickCheck
+-- import Test.QuickCheck.Instances ()
+import Test.HUnit hiding (Test)
+import Data.List (intercalate)
+
+import qualified TDD
+
+testDecode1 :: Assertion
+testDecode1 = assertEqual "for 1" 1 (TDD.add "1")
+
+propIntegerDecodeLoop :: Integer -> Bool
+propIntegerDecodeLoop num = TDD.add (show num) == num
+
+testDecodeEmpty :: Assertion
+testDecodeEmpty = assertEqual "for empty" 0 (TDD.add "")
+
+propTwoShouldDecode :: Integer -> Integer -> Bool
+propTwoShouldDecode x y = TDD.add (show x ++ "," ++ show y) == x + y
+
+propSomeShouldDecode :: [Integer] -> Bool
+propSomeShouldDecode xs = TDD.add (intercalate "," (map show xs)) == sum xs
+
+newtype Delimiter = Delimiter String deriving (Show)
+
+instance Arbitrary Delimiter where
+	arbitrary = Delimiter <$> elements [",", "\n"]
+
+propSomeShouldDecodeDelim :: [Integer] -> Delimiter ->  Bool
+propSomeShouldDecodeDelim xs (Delimiter d) = TDD.add (intercalate d (map show xs)) == sum xs
+
+tests :: [Test]
+tests =
+	[
+		testGroup "One number" [
+			testCase "\"1\" returns 1" testDecode1,
+			testProperty "Integer should decode" propIntegerDecodeLoop
+		],
+		testGroup "No number" [
+			testCase "\"\" returns 0" testDecodeEmpty
+		],
+		testGroup "Two numbers" [
+			testProperty "Two numbers should sum" propTwoShouldDecode
+		],
+		testGroup "Some numbers" [
+			testProperty "Some numbers should sum" propSomeShouldDecode,
+			testProperty "Some numbers should sum with comma or newline" propSomeShouldDecodeDelim
+		]
+	]
+
+main :: IO ()
+main = defaultMain tests