Convert trace warnings to hlint rules

Co-authored-by: Jan Beinke <git@janbeinke.com>

.hlint.yaml

+# HLint configuration file
+# https://github.com/ndmitchell/hlint
+##########################
+
+# This file contains a template configuration file, which is typically
+# placed as .hlint.yaml in the root of your project
+
+
+# Specify additional command line arguments
+#
+# - arguments: [--color, --cpp-simple, -XQuasiQuotes]
+
+
+# Control which extensions/flags/modules/functions can be used
+#
+# - extensions:
+#   - default: false # all extension are banned by default
+#   - name: [PatternGuards, ViewPatterns] # only these listed extensions can be used
+#   - {name: CPP, within: CrossPlatform} # CPP can only be used in a given module
+#
+# - flags:
+#   - {name: -w, within: []} # -w is allowed nowhere
+#
+# - modules:
+#   - {name: [Data.Set, Data.HashSet], as: Set} # if you import Data.Set qualified, it must be as 'Set'
+#   - {name: Control.Arrow, within: []} # Certain modules are banned entirely
+#
+# - functions:
+#   - {name: unsafePerformIO, within: []} # unsafePerformIO can only appear in no modules
+
+- functions:
+  - message: "Traces are not allowed in production code"
+    within: [Quasar.Prelude]
+    name:
+    - trace
+    - traceId
+    - traceShow
+    - traceShowId
+    - traceM
+    - traceShowM
+    - traceIO
+    - traceShowIO
+    - traceShowIdIO
+
+# Add custom hints for this project
+#
+# Will suggest replacing "wibbleMany [myvar]" with "wibbleOne myvar"
+# - error: {lhs: "wibbleMany [x]", rhs: wibbleOne x}
+
+# The hints are named by the string they display in warning messages.
+# For example, if you see a warning starting like
+#
+# Main.hs:116:51: Warning: Redundant ==
+#
+# You can refer to that hint with `{name: Redundant ==}` (see below).
+
+# Turn on hints that are off by default
+#
+# Ban "module X(module X) where", to require a real export list
+# - warn: {name: Use explicit module export list}
+#
+# Replace a $ b $ c with a . b $ c
+# - group: {name: dollar, enabled: true}
+#
+# Generalise map to fmap, ++ to <>
+# - group: {name: generalise, enabled: true}
+
+
+# Ignore some builtin hints
+# - ignore: {name: Use let}
+# - ignore: {name: Use const, within: SpecialModule} # Only within certain modules
+
+
+# Define some custom infix operators
+# - fixity: infixr 3 ~^#^~
+
+
+# To generate a suitable file for HLint do:
+# $ hlint --default > .hlint.yaml

flake.nix

@@ -40,6 +40,7 @@
           pkgs.entr
           pkgs.ghcid
           pkgs.haskell-language-server
+          pkgs.hlint
         ];
       }
     );

src/Quasar/Prelude.hs

@@ -31,8 +31,8 @@ module Quasar.Prelude
     Data.Void.Void,
     Data.Hashable.Hashable,
     GHC.Generics.Generic,
-    MonadIO,
-    liftIO,
+    Control.Monad.IO.Class.MonadIO,
+    Control.Monad.IO.Class.liftIO,
     Data.Maybe.catMaybes,
     Data.Maybe.fromMaybe,
     Data.Maybe.isJust,
@@ -49,15 +49,12 @@ module Quasar.Prelude
     Data.Word.Word64,
     error,
     errorWithoutStackTrace,
-    head,
-    last,
-    read,
-    trace,
-    traceId,
-    traceShow,
-    traceShowId,
-    traceM,
-    traceShowM,
+    Debug.Trace.trace,
+    Debug.Trace.traceId,
+    Debug.Trace.traceShow,
+    Debug.Trace.traceShowId,
+    Debug.Trace.traceM,
+    Debug.Trace.traceShowM,
     traceIO,
     traceShowIO,
     traceShowIdIO,
@@ -86,7 +83,7 @@ import Control.Exception qualified
 import Control.Monad ((>=>), (<=<))
 import Control.Monad qualified
 import Control.Monad.Fix qualified
-import Control.Monad.IO.Class (MonadIO, liftIO)
+import Control.Monad.IO.Class qualified
 import Data.Foldable qualified
 import Data.Functor.Identity qualified
 import Data.Hashable qualified
@@ -96,25 +93,13 @@ import Data.Maybe qualified
 import Data.Unique qualified
 import Data.Void qualified
 import Data.Word qualified
-import Debug.Trace qualified as Trace
+import Debug.Trace qualified
 import GHC.Generics qualified
 import GHC.Stack.Types qualified
 import GHC.Types qualified
 import Quasar.PreludeExtras
 import Quasar.PreludeSTM
 
-{-# WARNING head "Partial Function." #-}
-head :: [a] -> a
-head = P.head
-
-{-# WARNING last "Partial Function." #-}
-last :: [a] -> a
-last = P.last
-
-{-# WARNING read "Partial Function." #-}
-read :: Read a => String -> a
-read = P.read
-
 {-# WARNING error "Undefined." #-}
 error :: forall (r :: GHC.Types.RuntimeRep). forall (a :: GHC.Types.TYPE r). GHC.Stack.Types.HasCallStack => String -> a
 error = P.error
@@ -127,41 +112,14 @@ errorWithoutStackTrace = P.errorWithoutStackTrace
 undefined :: forall (r :: GHC.Types.RuntimeRep). forall (a :: GHC.Types.TYPE r). GHC.Stack.Types.HasCallStack  => a
 undefined = P.undefined
 
-{-# WARNING trace "Trace." #-}
-trace :: String -> a -> a
-trace = Trace.trace
-
-{-# WARNING traceId "Trace." #-}
-traceId :: String -> String
-traceId = Trace.traceId
-
-{-# WARNING traceShow "Trace." #-}
-traceShow :: Show a => a -> b -> b
-traceShow = Trace.traceShow
-
-{-# WARNING traceShowId "Trace." #-}
-traceShowId :: Show a => a -> a
-traceShowId = Trace.traceShowId
-
-{-# WARNING traceM "Trace." #-}
-traceM :: Applicative m => String -> m ()
-traceM = Trace.traceM
-
-{-# WARNING traceShowM "Trace." #-}
-traceShowM :: (Show a, Applicative m) => a -> m ()
-traceShowM = Trace.traceShowM
-
-{-# WARNING traceIO "Trace." #-}
 traceIO :: Control.Monad.IO.Class.MonadIO m => String -> m ()
-traceIO = Control.Monad.IO.Class.liftIO . Trace.traceIO
+traceIO = Control.Monad.IO.Class.liftIO . Debug.Trace.traceIO
 
-{-# WARNING traceShowIO "Trace." #-}
 traceShowIO :: (Control.Monad.IO.Class.MonadIO m, Show a) => a -> m ()
 traceShowIO = traceIO . show
 
-{-# WARNING traceShowIdIO "Trace." #-}
 traceShowIdIO :: (Control.Monad.IO.Class.MonadIO m, Show a) => a -> m a
 traceShowIdIO a = traceShowIO a >> pure a
 
-newUnique :: MonadIO m => m Data.Unique.Unique
-newUnique = liftIO Data.Unique.newUnique
+newUnique :: Control.Monad.IO.Class.MonadIO m => m Data.Unique.Unique
+newUnique = Control.Monad.IO.Class.liftIO Data.Unique.newUnique