From d8e2cc101d8aed77ec6c76ddbde3c1785e35cde9 Mon Sep 17 00:00:00 2001
From: James Brechtel <git@jamesbrechtel.com>
Date: Tue, 19 May 2026 23:23:04 -0400
Subject: [PATCH] fix: correct path handling in live recipe watching

- Strip .cook from map keys to match lookupRecipe behavior
- Use makeRelative for event paths to match relative map keys
- Filter watcher to only .cook files
- Log watcher thread exceptions
- Use imported isSuffixOf from Data.List
---
 src/Roux/Server.hs | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/src/Roux/Server.hs b/src/Roux/Server.hs
index d4449eb..55ddb30 100644
--- a/src/Roux/Server.hs
+++ b/src/Roux/Server.hs
@@ -11,10 +11,12 @@ module Roux.Server (
 
 import Control.Concurrent (forkIO)
 import Control.Concurrent.Chan (Chan, newChan, readChan)
+import Control.Exception (SomeException, catch)
 import Control.Monad (when)
 import Data.ByteString.Lazy (ByteString)
 import Data.Char (toLower)
 import Data.IORef (IORef, atomicModifyIORef', newIORef, readIORef)
+import Data.List (isSuffixOf)
 import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as Map
 import Data.Text (Text)
@@ -31,7 +33,7 @@ import System.FSNotify (
     watchTreeChan,
     withManagerConf,
  )
-import System.FilePath ((</>))
+import System.FilePath (makeRelative, (</>))
 
 import qualified Roux.Html as Html
 import qualified Roux.RecipeIndex as Idx
@@ -51,11 +53,14 @@ app recipeDir = do
     when (errs > 0) $
         putStrLn $
             "[roux] " <> show errs <> " had parse errors"
-    -- Build initial map keyed by lowercased filename
-    let recipeMap = Map.fromList [(map toLower (Idx.riFilename r), r) | r <- recipes]
+    -- Build initial map keyed by lowercased filename (without .cook extension)
+    let recipeMap = Map.fromList [(map toLower (stripCookExt (Idx.riFilename r)), r) | r <- recipes]
     state <- newIORef recipeMap
     -- Start the filesystem watcher
-    _ <- forkIO (watchRecipes recipeDir state)
+    _ <-
+        forkIO $
+            watchRecipes recipeDir state `catch` \e ->
+                putStrLn $ "[roux] watcher thread crashed: " <> show (e :: SomeException)
     pure (handleRequest state)
   where
     isRight (Right _) = True
@@ -70,23 +75,23 @@ watchRecipes dir state = do
     let cfg = defaultConfig{confWatchMode = WatchModeOS}
     withManagerConf cfg $ \mgr -> do
         chan <- newChan
-        _stopListening <- watchTreeChan mgr dir (const True) chan
+        _stopListening <- watchTreeChan mgr dir ((".cook" `isSuffixOf`) . eventPath) chan
         debounceLoop chan state dir Map.empty
   where
     debounceLoop :: Chan Event -> IORef (Map FilePath Idx.RecipeInfo) -> FilePath -> Map FilePath UTCTime -> IO ()
     debounceLoop chan st dr lastSeen = do
         ev <- readChan chan
-        let isDir = eventIsDirectory ev
-        now <- getCurrentTime
-        if isDir == IsDirectory
+        if eventIsDirectory ev == IsDirectory
             then debounceLoop chan st dr lastSeen
             else do
-                let path = eventPath ev
-                let key = map toLower path
+                let path = makeRelative dr (eventPath ev)
+                let key = map toLower (stripCookExt path)
+                now <- getCurrentTime
                 let lastTime = Map.lookup key lastSeen
                 case lastTime of
-                    Just t | diffUTCTime now t < 0.2 -> do
-                        debounceLoop chan st dr lastSeen
+                    Just t
+                        | diffUTCTime now t < 0.2 ->
+                            debounceLoop chan st dr lastSeen
                     _ -> do
                         reReadRecipe dr path st
                         debounceLoop chan st dr (Map.insert key now lastSeen)
@@ -96,17 +101,16 @@ On read/parse errors, logs the error and keeps the previous version.
 -}
 reReadRecipe :: FilePath -> FilePath -> IORef (Map FilePath Idx.RecipeInfo) -> IO ()
 reReadRecipe dir path state = do
+    let key = map toLower (stripCookExt path)
     let fullPath = dir </> path
     exists <- doesFileExist fullPath
     if not exists
         then do
-            let key = map toLower path
             atomicModifyIORef' state $ \m ->
                 (Map.delete key m, ())
             putStrLn $ "[roux] removed " <> path
         else do
             info <- Idx.loadRecipe dir path
-            let key = map toLower path
             case Idx.riRecipe info of
                 Left err -> do
                     putStrLn $ "[roux] parse error in " <> path <> ": " <> err
@@ -145,8 +149,6 @@ stripCookExt :: FilePath -> FilePath
 stripCookExt fp
     | ".cook" `isSuffixOf` fp = take (length fp - 5) fp
     | otherwise = fp
-  where
-    isSuffixOf suffix s = suffix == drop (length s - length suffix) s
 
 -- | Decode a percent-encoded URL path segment to a FilePath.
 urlDecodePath :: Text -> FilePath