Put a little responsability back into Main to avoid Arguments having control on main flow

src/Arguments.hs

@@ -10,7 +10,7 @@ import Options.Applicative (Parser, ReadM, argument, auto, eitherReader, execPar
 import qualified Options.Applicative as Optparse (option)
 import qualified Paths_hablo as Hablo (version)
 import System.Directory (doesDirectoryExist, doesFileExist, makeAbsolute)
-import System.Exit (die, exitSuccess)
+import System.Exit (die)
 import System.FilePath ((</>), dropTrailingPathSeparator, isValid)
 
 data Arguments = BlogConfig {
@@ -118,10 +118,8 @@ checkAndMakeAbsolute aBlogConfig = do
 
 get :: IO Arguments
 get = do
-  args <- execParser $
-    info
-      (arguments <**> helper)
-      (fullDesc <> header ("Hablo v" ++ showVersion Hablo.version))
-  case args of
-    Version -> (putStrLn $ showVersion Hablo.version) >> exitSuccess
-    BlogConfig {} -> checkAndMakeAbsolute args
+  checkAndMakeAbsolute =<< (execParser $
+      info
+        (arguments <**> helper)
+        (fullDesc <> header ("Hablo v" ++ showVersion Hablo.version))
+    )

src/Main.hs

@@ -1,16 +1,21 @@
 module Main where
 
+import Arguments (Arguments(..))
 import qualified Arguments (get)
 import qualified Blog (build)
+import Control.Monad.Reader (runReaderT)
+import Data.Version (showVersion)
 import qualified HTML (generate)
 import qualified JS (generate)
-import Control.Monad.Reader (runReaderT)
+import qualified Paths_hablo as Hablo (version)
+import System.Exit (exitSuccess)
 
 main :: IO ()
 main = do
-  Arguments.get
-  >>= Blog.build
-  >>= runReaderT (do
-    HTML.generate
-    JS.generate
-  )
+  arguments <- Arguments.get
+  case arguments of
+    Version -> (putStrLn $ showVersion Hablo.version) >> exitSuccess
+    config@(BlogConfig {}) -> Blog.build config >>= runReaderT (do
+        HTML.generate
+        JS.generate
+      )