Fix formatting and errors

app/Main.hs

@@ -1,27 +1,22 @@
-module Main where
-
-import           System.Environment (getArgs)
-import           System.Exit
-import           Text.Parsec.Error  (ParseError)
+module Main
+  ( main
+  ) where
 
 import           Data.Dates
-import           Pattern
+import           Pattern            (match)
+import           System.Environment (getArgs)
+import           System.Exit
 
 main :: IO ()
 main = do
   args <- getArgs
-  dt <- getCurrentDateTime
+  currentDateTime <- getCurrentDateTime
   exitWith $
-    case processArgs args dt of
+    case processArgs args currentDateTime of
       Just True  -> ExitSuccess
       Just False -> ExitFailure 1
       Nothing    -> ExitFailure 2
 
 processArgs :: [String] -> DateTime -> Maybe Bool
-processArgs [ptn] dt       = safeMatch ptn dt
-processArgs [ptn, time] dt = matchGivenTime ptn (parseDate dt time)
+processArgs [ptn] dt = match ptn dt
 processArgs _ _      = Nothing
-
-matchGivenTime :: String -> Either ParseError DateTime -> Maybe Bool
-matchGivenTime _ (Left _)     = Nothing
-matchGivenTime ptn (Right dt) = safeMatch ptn dt

src/Constraint.hs

@@ -1,15 +1,16 @@
-module Constraint where
+module Constraint
+  ( Constraint(..)
+  , inRange
+  , inside
+  ) where
 
 data Constraint = Constraint
   { lower :: Int
   , upper :: Int
   } deriving (Show, Eq)
 
-makeRangeFromNumber :: Int -> Constraint
-makeRangeFromNumber x = Constraint x x
-
 inside :: (Int, Int) -> Constraint -> Bool
-inside (x, y) (Constraint lower upper) = x >= lower && y <= upper
+inside (x, y) (Constraint lw up) = x >= lw && y <= up
 
 inRange :: Int -> Constraint -> Bool
 inRange x = inside (x, x)

src/Field.hs

@@ -1,4 +1,6 @@
-module Field where
+module Field
+  ( module Field
+  ) where
 
 import           Constraint
 import           Data.Char  (isDigit)
@@ -44,11 +46,12 @@ parseFieldRange text constraint
   | text == "*" = Just All
   | isJust number = Just (Range (fromJust number) (fromJust number))
   | isJust range = Just (uncurry Range (fromJust range))
-  | isJust sequence = fmap Sequence sequence
+  | isJust valueSequence = fmap Sequence valueSequence
+  | otherwise = Nothing
   where
     number = parseNumber text constraint
     range = parseRange text constraint
-    sequence = parseSequence text constraint
+    valueSequence = parseSequence text constraint
 
 isNumber :: String -> Bool
 isNumber = all isDigit

src/Helper.hs

@@ -1,4 +1,6 @@
-module Helper where
+module Helper
+  ( wordsWhen
+  ) where
 
 wordsWhen :: (Char -> Bool) -> String -> [String]
 wordsWhen p s =

src/Pattern.hs

@@ -1,11 +1,9 @@
 module Pattern
   ( Pattern(..)
   , match
-  , safeMatch
   , parse
   , check
-  , createParts
-  , parseField
+  , createFields
   ) where
 
 import           Constraint
@@ -20,16 +18,10 @@ data Pattern = Pattern
   , cmonth  :: Field
   , cweek   :: Field
   , cyear   :: Field
-  }
+  } deriving (Show)
 
-match :: String -> DateTime -> Bool
+match :: String -> DateTime -> Maybe Bool
 match s d =
-  case parse s of
-    Just p  -> check p d
-    Nothing -> error "Parse error"
-
-safeMatch :: String -> DateTime -> Maybe Bool
-safeMatch s d =
   case parse s of
     Just p  -> Just (check p d)
     Nothing -> Nothing
@@ -39,7 +31,7 @@ parse s
   | isInvalid = Nothing
   | otherwise = Just (createPattern $ catMaybes parts)
   where
-    parts = createParts s
+    parts = createFields s
     isInvalid = not (checkParts parts)
     createPattern xs =
       Pattern
@@ -51,9 +43,10 @@ parse s
       , cyear = xs !! 5
       }
 
-createParts s = zipWith (curry f) parsers (words s)
+createFields :: String -> [Maybe Field]
+createFields text = zipWith (curry f) parsers (words text)
   where
-    f (g, s) = g s
+    f (parser, s) = parser s
 
 checkParts :: [Maybe Field] -> Bool
 checkParts xs
@@ -64,18 +57,25 @@ checkParts xs
 parseFieldAdapter :: Constraint -> String -> Maybe Field
 parseFieldAdapter c t = parseField t c
 
+parseMinute :: String -> Maybe Field
 parseMinute = parseFieldAdapter (Constraint 0 59)
 
-parseHour = parseFieldAdapter (Constraint 0 59)
+parseHour :: String -> Maybe Field
+parseHour = parseFieldAdapter (Constraint 0 23)
 
+parseDay :: String -> Maybe Field
 parseDay = parseFieldAdapter (Constraint 1 31)
 
+parseMonth :: String -> Maybe Field
 parseMonth = parseFieldAdapter (Constraint 1 12)
 
+parseWeek :: String -> Maybe Field
 parseWeek = parseFieldAdapter (Constraint 1 7)
 
+parseYear :: String -> Maybe Field
 parseYear = parseFieldAdapter (Constraint 0 9999)
 
+parsers :: [String -> Maybe Field]
 parsers = [parseMinute, parseHour, parseDay, parseMonth, parseWeek, parseYear]
 
 check :: Pattern -> DateTime -> Bool

test/ConstraintSpec.hs

@@ -12,7 +12,5 @@ main = hspec spec
 spec :: Spec
 spec =
   describe "Constraint" $ do
-    it "can be created from number" $
-      makeRangeFromNumber 10 `shouldBe` Constraint 10 10
     it "validate number" $ 10 `inRange` Constraint 0 10 `shouldBe` True
     it "validate number" $ 10 `inRange` Constraint 15 20 `shouldBe` False

test/FieldSpec.hs

@@ -34,21 +34,21 @@ spec = do
   describe "Step can be created from" $ do
     it "empty string" $ parseFieldStep "" `shouldBe` Just Every
     it "number" $ parseFieldStep "5" `shouldBe` Just (Step 5)
-  describe "Step cant'b created from" $ do
+  describe "Step cant'b created from" $
     it "word" $ parseFieldStep "hello" `shouldBe` Nothing
   -- Field validation
   describe "Field can be created from" $ do
     it "asterisk" $
       parseField "*" (Constraint 0 59) `shouldBe` Just (Field All Every)
-    it "asterisk with step" $ do
+    it "asterisk with step" $
       parseField "*/5" (Constraint 0 59) `shouldBe` Just (Field All (Step 5))
-    it "number with step" $ do
+    it "number with step" $
       parseField "10/5" (Constraint 0 59) `shouldBe`
       Just (Field (Range 10 10) (Step 5))
-    it "range with step" $ do
+    it "range with step" $
       parseField "0-59/5" (Constraint 0 59) `shouldBe`
       Just (Field (Range 0 59) (Step 5))
-    it "sequence with step" $ do
+    it "sequence with step" $
       parseField "1,3,4/5" (Constraint 0 59) `shouldBe`
       Just (Field (Sequence [1, 3, 4]) (Step 5))
   -- Field match

test/PatternSpec.hs

@@ -4,6 +4,7 @@ module PatternSpec
   ) where
 
 import           Data.Dates
+import           Data.Maybe
 import           Pattern
 import           Test.Hspec
 
@@ -11,13 +12,13 @@ main :: IO ()
 main = hspec spec
 
 spec :: Spec
-spec = do
+spec =
   describe "Cron pattern" $ do
-    it "createParts" $ length (createParts "* * * * * *") `shouldBe` 6
+    it "createFields" $ length (createFields "* * * * * *") `shouldBe` 6
     it "matches fixed time" $
       let ptn = "* * * * * *"
           date = DateTime 2017 10 11 0 0 0
-      in match ptn date `shouldBe` True
+      in match ptn date `shouldBe` Just True
     it "matches all minutes" $
       let ptn = "* * * * * *"
           dates = [DateTime 2017 10 11 0 i 0 | i <- [0 .. 59]]
@@ -25,12 +26,16 @@ spec = do
     it "matches exactly moment" $
       let date = DateTime 2017 10 11 0 0 0
           ptn = "0 0 11 10 * 2017"
-      in match ptn date `shouldBe` True
+      in match ptn date `shouldBe` Just True
+    it "matches moment" $
+      let date = DateTime 2017 10 10 12 10 0
+          ptn = "* 12 * * * *"
+      in match ptn date `shouldBe` Just True
 
 countMatches :: String -> [DateTime] -> Int
 countMatches p xs = sum $ map (f p) xs
   where
     f x d =
-      if match x d
+      if isJust $ match x d
         then 1
         else 0