Add tests for DateExpr

test/Spec.hs

@@ -1,2 +1,41 @@
+import           Test.Hspec
+
+import Tests.DateExpr
+
+{-
+parseEval :: String -> Maybe Integer
+parseEval str =
+  let day  = ModifiedJulianDay 0
+      expr = TM.parseIntExpr str
+  in  expr >>= flip TM.evalIntExpr day
+
+prop_ParseInteger :: Integer -> Bool
+prop_ParseInteger n = parseEval (show n) == Just n
+
+prop_ParseAddSub :: Integer -> Integer -> Integer -> Integer -> Bool
+prop_ParseAddSub a b c d =
+  let formula = show a ++ "+" ++ show b ++ "- (" ++ show c ++ "+" ++ show d ++ ")"
+      expected = a + b - (c + d)
+  in  parseEval formula == Just expected
+
+prop_ParseMultDiv :: Integer -> Integer -> Integer -> Integer -> Property
+prop_ParseMultDiv a b c d =
+  let formula = show a ++ "*" ++ show b ++ "/ (" ++ show c ++ "*" ++ show d ++ ")"
+      expected = a * b `div` (c * d)
+  in  (c * d /= 0) ==> parseEval formula == Just expected
+
 main :: IO ()
-main = putStrLn "Test suite not yet implemented"
+main = hspec $ do
+  describe "Expressions" $ do
+    describe "IntExpr" $ do
+      it "parses integers" $ property $ prop_ParseInteger
+      it "parses addition and subtraction" $ property $ prop_ParseAddSub
+      it "parses multiplication and division" $ property $ prop_ParseMultDiv
+      it "parses a complicated equation" $
+        parseEval "12 - (2 / 5) * 3 + ((37))" `shouldBe` Just (12 - (2 `div` 5) * 3 + 37)
+    describe "BoolExpr" $ do
+-}
+
+main :: IO ()
+main = hspec $ do
+  testDateExpr