Make run return ExitCode

2 files changed, 13 insertions, 13 deletions

diff --git a/src/Hakyll/Commands.hs b/src/Hakyll/Commands.hs
index 61e40b8..4c60783 100644
--- a/src/Hakyll/Commands.hs
+++ b/src/Hakyll/Commands.hs
@@ -13,7 +13,7 @@ module Hakyll.Commands
 
 
 --------------------------------------------------------------------------------
-import           System.Exit                (exitWith)
+import           System.Exit                (ExitCode (ExitSuccess), exitWith)
 import           System.Process             (system)
 
 
@@ -69,15 +69,16 @@ clean conf = do
 preview :: Configuration -> Verbosity -> Rules a -> Int -> IO ()
 #ifdef PREVIEW_SERVER
 preview conf verbosity rules port = do
-    -- Fork a thread polling for changes
-    _ <- forkIO $ previewPoll conf update
-
-    -- Run the server in the main thread
-    server conf port
+    -- Run the server in a separate thread
+    _ <- forkIO $ server conf port
+    previewPoll conf update
   where
     update = do
-        ruleSet <- run conf verbosity rules
-        return $ map toFilePath $ S.toList $ rulesResources ruleSet
+        (exitCode, ruleSet) <- run conf verbosity rules
+        case exitCode of
+            ExitSuccess -> return $ map toFilePath $ S.toList $
+                rulesResources ruleSet
+            _           -> exitWith exitCode
 #else
 preview _ _ _ _ = previewServerDisabled
 #endif
diff --git a/src/Hakyll/Core/Runtime.hs b/src/Hakyll/Core/Runtime.hs
index 1b83692..39d72a7 100644
--- a/src/Hakyll/Core/Runtime.hs
+++ b/src/Hakyll/Core/Runtime.hs
@@ -17,7 +17,7 @@ import qualified Data.Map                      as M
 import           Data.Monoid                   (mempty)
 import           Data.Set                      (Set)
 import qualified Data.Set                      as S
-import           System.Exit                   (ExitCode (..), exitWith)
+import           System.Exit                   (ExitCode (..))
 import           System.FilePath               ((</>))
 
 
@@ -41,8 +41,7 @@ import           Hakyll.Core.Writable
 
 
 --------------------------------------------------------------------------------
--- | TODO Make this return exit code?
-run :: Configuration -> Verbosity -> Rules a -> IO RuleSet
+run :: Configuration -> Verbosity -> Rules a -> IO (ExitCode, RuleSet)
 run config verbosity rules = do
     -- Initialization
     logger <- Logger.new verbosity
@@ -82,7 +81,7 @@ run config verbosity rules = do
         Left e          -> do
             Logger.error logger e
             Logger.flush logger
-            exitWith $ ExitFailure 1
+            return (ExitFailure 1, ruleSet)
 
         Right (_, s, _) -> do
             Store.set store factsKey $ runtimeFacts s
@@ -91,7 +90,7 @@ run config verbosity rules = do
             removeDirectory $ tmpDirectory config
 
             Logger.flush logger
-            return ruleSet
+            return (ExitSuccess, ruleSet)
   where
     factsKey = ["Hakyll.Core.Runtime.run", "facts"]