Hlint: A handful of fixes to hints (#3259)

* CI: rwe/actions-hlint-run v2

* fmt script: Fix missing directories

Otherwise will fail

* Hlint: Automatically fix warnings via apply-refact

* Hlint: Do not suggest fromMaybe

Co-authored-by: Michael Peyton Jones <me@michaelpj.com>

Author: andys8

.github/workflows/hlint.yml

@@ -18,7 +18,7 @@ jobs:
         version: '3.4'
 
     - name: 'Checking code'
-      uses: rwe/actions-hlint-run@v1
+      uses: rwe/actions-hlint-run@v2
       with:
         hlint-bin: "hlint --with-group=extra"
         fail-on: error

.hlint.yaml

@@ -23,6 +23,7 @@
 - ignore: {name: "Use camelCase"}
 - ignore: {name: "Use uncurry"}
 - ignore: {name: "Avoid lambda using `infix`"}
+- ignore: {name: "Replace case with fromMaybe"}
 
 # Gives at least one suggestion we don't like.
 - ignore: {name: "Use <=<"}
@@ -65,11 +66,11 @@
     - Wingman.Types
     - AutoTupleSpec
   - name: unsafeInterleaveIO
-    within: 
+    within:
     - Development.IDE.LSP.LanguageServer
   - {name: unsafeDupablePerformIO, within: []}
   - name: unsafeCoerce
-    within: 
+    within:
     - Ide.Plugin.Eval.Code
     - Development.IDE.Core.Compile
     - Development.IDE.Types.Shake
@@ -85,12 +86,12 @@
     - Compat.HieBin
 
   # Partial functions
-  
+
   # We need to check fucntions which
   # are typically exported multiple ways under both names,
   # see https://github.com/ndmitchell/hlint/issues/1389
   - name: [Prelude.head, Data.List.head]
-    within: 
+    within:
     - Main
     - Experiments
     - Development.Benchmark.Rules
@@ -116,7 +117,7 @@
     - Wingman.Tactics
 
   - name: [Prelude.tail, Data.List.tail]
-    within: 
+    within:
     - Main
     - Development.Benchmark.Rules
     - Development.IDE.Plugin.CodeAction
@@ -125,7 +126,7 @@
     - UnificationSpec
 
   - name: [Prelude.last, Data.List.last]
-    within: 
+    within:
     - Main
     - Development.IDE.Plugin.CodeAction
     - Development.IDE.Plugin.CodeAction.ExactPrint
@@ -136,7 +137,7 @@
     - Ide.Plugin.Eval.CodeLens
 
   - name: [Prelude.init, Data.List.init]
-    within: 
+    within:
     - Main
     - Development.IDE.Spans.Common
     - Ide.PluginUtils
@@ -151,7 +152,7 @@
     within: []
 
   - name: ["Prelude.!!", "Data.List.!!"]
-    within: 
+    within:
     - Main
     - Experiments
     - FunctionalCodeAction
@@ -171,11 +172,11 @@
     within: []
 
   - name: Data.Foldable.foldr1
-    within: 
+    within:
     - Wingman.Tactics
 
-  - name: Data.Maybe.fromJust 
-    within: 
+  - name: Data.Maybe.fromJust
+    within:
     - Experiments
     - Main
     - MultipleImports
@@ -193,7 +194,7 @@
     - Ide.Plugin.Class
 
   - name: "Data.Map.!"
-    within: 
+    within:
     - Wingman.LanguageServer
 
   - name: "Data.IntMap.!"
@@ -210,7 +211,7 @@
   # Debug.Trace, because that module also
   # includes the eventlog tracing functions,
   # which are legitimate to use.
-  - name: 
+  - name:
     - Debug.Trace.trace
     - Debug.Trace.traceId
     - Debug.Trace.traceShow
@@ -220,7 +221,7 @@
     - Debug.Trace.traceM
     - Debug.Trace.traceShowM
     - Debug.Trace.putTraceMsg
-    within: 
+    within:
     - Development.IDE.Core.Compile
     - Development.IDE.Graph.Internal.Database
     - Development.IDE.GHC.Util

bench/Main.hs

@@ -44,7 +44,6 @@
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE TypeFamilies       #-}
 {-# OPTIONS -Wno-orphans #-}
-{-# LANGUAGE PackageImports     #-}
 
 import           Control.Lens                (preview, (^.))
 import           Control.Monad.Extra

exe/Wrapper.hs

@@ -12,11 +12,11 @@
 module Main where
 
 import           Control.Monad.Extra
-import           Data.Char                          (isSpace)
 import           Data.Default
 import           Data.Either.Extra                  (eitherToMaybe)
 import           Data.Foldable
 import           Data.List
+import           Data.List.Extra                    (trimEnd)
 import           Data.Void
 import qualified Development.IDE.Session            as Session
 import qualified HIE.Bios.Environment               as HieBios
@@ -232,7 +232,7 @@ findProjectCradle' log = do
 trim :: String -> String
 trim s = case lines s of
   [] -> s
-  ls -> dropWhileEnd isSpace $ last ls
+  ls -> trimEnd $ last ls
 
 data WrapperSetupError
     = FailedToObtainGhcVersion (ActionName Void) CradleError

fmt.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 set -eou pipefail
-curl -sSL https://raw.github.com/ndmitchell/hlint/master/misc/run.sh | sh -s ghcide/src ghcide/exe ghcide/bench/lib ghcide/bench/exe ghcide/bench/hist shake-bench/src ghcide/test/exe --with-group=extra --hint=ghcide/.hlint.yaml
+curl -sSL https://raw.github.com/ndmitchell/hlint/master/misc/run.sh | sh -s ghcide/src ghcide/exe ghcide-bench/exe shake-bench/src ghcide/test/exe --with-group=extra --hint=.hlint.yaml

ghcide-bench/src/Experiments.hs

@@ -538,7 +538,7 @@ runBench runSess b = handleAny (\e -> print e >> return badRun)
                 output (showDuration t)
                 -- Wait for the delayed actions to finish
                 td <- waitForBuildQueue
-                loop' (timeForFirstResponse <|> (Just (t,td))) (userWaits+t) (delayedWork+td) (n -1)
+                loop' (timeForFirstResponse <|> Just (t,td)) (userWaits+t) (delayedWork+td) (n -1)
           loop = loop' Nothing
 
       (runExperiment, result) <- duration $ loop 0 0 samples

ghcide/src/Development/IDE/Core/Compile.hs

@@ -308,7 +308,7 @@ captureSplicesAndDeps TypecheckHelpers{..} env k = do
                  mods_transitive = getTransitiveMods hsc_env needed_mods
 
                  -- If we don't support multiple home units, ModuleNames are sufficient because all the units will be the same
-                 mods_transitive_list = 
+                 mods_transitive_list =
 #if MIN_VERSION_ghc(9,3,0)
                                          mapMaybe nodeKeyToInstalledModule $ Set.toList mods_transitive
 #else
@@ -362,7 +362,7 @@ captureSplicesAndDeps TypecheckHelpers{..} env k = do
 #endif
 
     -- Compute the transitive set of linkables required
-    getTransitiveMods hsc_env needed_mods 
+    getTransitiveMods hsc_env needed_mods
 #if MIN_VERSION_ghc(9,3,0)
       = Set.unions (Set.fromList (map moduleToNodeKey mods) : [ dep | m <- mods
                                                               , Just dep <- [Map.lookup (moduleToNodeKey m) (mgTransDeps (hsc_mod_graph hsc_env))]
@@ -561,7 +561,7 @@ mkHiFileResultCompile se session' tcm simplified_guts = catchErrs $ do
 
 
       when (not $ null diffs) $
-        panicDoc "verify core failed!" (vcat $ punctuate (text "\n\n") (diffs )) -- ++ [ppr binds , ppr binds']))
+        panicDoc "verify core failed!" (vcat $ punctuate (text "\n\n") diffs) -- ++ [ppr binds , ppr binds']))
     _ -> pure ()
 
   pure ([], Just $! mkHiFileResult ms final_iface details (tmrRuntimeModules tcm) core_file)

ghcide/src/Development/IDE/Core/Rules.hs

@@ -697,7 +697,7 @@ typeCheckRuleDefinition hsc pm = do
 
   unlift <- askUnliftIO
   let dets = TypecheckHelpers
-           { getLinkablesToKeep = unliftIO unlift $ currentLinkables
+           { getLinkablesToKeep = unliftIO unlift currentLinkables
            , getLinkables = unliftIO unlift . uses_ GetLinkable
            }
   addUsageDependencies $ liftIO $

ghcide/src/Development/IDE/Main.hs

@@ -283,7 +283,7 @@ testing recorder logger =
     hlsPlugins = pluginDescToIdePlugins $
       idePluginsToPluginDesc argsHlsPlugins
       ++ [Test.blockCommandDescriptor "block-command", Test.plugin]
-    ideOptions = \config sessionLoader ->
+    ideOptions config sessionLoader =
       let
         defOptions = argsIdeOptions config sessionLoader
       in

hie-compat/src-ghc86/Compat/HieTypes.hs

@@ -5,7 +5,7 @@ For more information see https://gitlab.haskell.org/ghc/ghc/wikis/hie-files
 -}
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE TypeSynonymInstances #-}
+
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# OPTIONS_GHC -Wno-orphans #-}

hie-compat/src-ghc86/Compat/HieUtils.hs

@@ -127,7 +127,7 @@ recoverFullType i m = go i
 
 getTypeIndex :: Type -> State HieTypeState TypeIndex
 getTypeIndex t
-  | otherwise = do
+   = do
       tm <- gets tyMap
       case lookupTypeMap tm t of
         Just i -> return i

hls-graph/src/Development/IDE/Graph/Internal/Database.hs

@@ -1,7 +1,7 @@
 -- We deliberately want to ensure the function we add to the rule database
 -- has the constraints we need on it when we get it out.
 {-# OPTIONS_GHC -Wno-redundant-constraints #-}
-{-# LANGUAGE DeriveFunctor              #-}
+
 {-# LANGUAGE DerivingStrategies         #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE RankNTypes                 #-}

hls-plugin-api/src/Ide/Plugin/ConfigUtils.hs

@@ -12,7 +12,7 @@ import qualified Data.Aeson.Types      as A
 import           Data.Default          (def)
 import qualified Data.Dependent.Map    as DMap
 import qualified Data.Dependent.Sum    as DSum
-import           Data.List             (nub)
+import           Data.List.Extra       (nubOrd)
 import           Data.String           (IsString (fromString))
 import qualified Data.Text             as T
 import           Ide.Plugin.Config
@@ -62,7 +62,7 @@ pluginsToDefaultConfig IdePlugins {..} =
         -- }
         --
         genericDefaultConfig =
-          let x = ["diagnosticsOn" A..= True | configHasDiagnostics] <> nub (mconcat (handlersToGenericDefaultConfig <$> handlers))
+          let x = ["diagnosticsOn" A..= True | configHasDiagnostics] <> nubOrd (mconcat (handlersToGenericDefaultConfig <$> handlers))
            in case x of
                 -- if the plugin has only one capability, we produce globalOn instead of the specific one;
                 -- otherwise we don't produce globalOn at all
@@ -106,7 +106,7 @@ pluginsToVSCodeExtensionSchema IdePlugins {..} = A.object $ mconcat $ singlePlug
         genericSchema =
           let x =
                 [toKey' "diagnosticsOn" A..= schemaEntry "diagnostics" | configHasDiagnostics]
-                  <> nub (mconcat (handlersToGenericSchema <$> handlers))
+                  <> nubOrd (mconcat (handlersToGenericSchema <$> handlers))
            in case x of
                 -- If the plugin has only one capability, we produce globalOn instead of the specific one;
                 -- otherwise we don't produce globalOn at all

plugins/hls-alternate-number-format-plugin/hls-alternate-number-format-plugin.cabal

@@ -31,6 +31,7 @@ library
       aeson
     , base                 >=4.12 && < 5
     , containers
+    , extra
     , ghcide               ^>= 1.8
     , ghc-boot-th
     , hls-graph

plugins/hls-alternate-number-format-plugin/src/Ide/Plugin/Conversion.hs

@@ -23,6 +23,7 @@ module Ide.Plugin.Conversion (
 
 import           Data.Char                     (toUpper)
 import           Data.List                     (delete)
+import           Data.List.Extra               (enumerate, upper)
 import           Data.Maybe                    (mapMaybe)
 import           Data.Ratio                    (denominator, numerator)
 import           Data.Text                     (Text)
@@ -108,10 +109,10 @@ filterFracFormats = mapMaybe getFracFormat
         getFracFormat _              = Nothing
 
 intFormats :: [IntFormatType]
-intFormats = [minBound .. maxBound]
+intFormats = enumerate
 
 fracFormats :: [FracFormatType]
-fracFormats = [minBound .. maxBound]
+fracFormats = enumerate
 
 -- | Regex to match a Haskell Hex Literal
 hexRegex :: Text
@@ -157,8 +158,8 @@ sourceToFormatType srcText
 
 toBase :: (Num a, Ord a) => (a -> ShowS) -> String -> a -> String
 toBase conv header n
-  | n < 0 = '-' : header <> map toUpper (conv (abs n) "")
-  | otherwise = header <> map toUpper (conv n "")
+  | n < 0 = '-' : header <> upper (conv (abs n) "")
+  | otherwise = header <> upper (conv n "")
 
 toOctal :: (Integral a, Show a) => a -> String
 toOctal = toBase showOct "0o"

plugins/hls-code-range-plugin/src/Ide/Plugin/CodeRange.hs

@@ -19,6 +19,7 @@ import           Control.Monad.IO.Class               (liftIO)
 import           Control.Monad.Trans.Maybe            (MaybeT (MaybeT),
                                                        maybeToExceptT)
 import           Data.Either.Extra                    (maybeToEither)
+import           Data.List.Extra                      (drop1)
 import           Data.Maybe                           (fromMaybe)
 import           Data.Vector                          (Vector)
 import qualified Data.Vector                          as V
@@ -206,7 +207,7 @@ findPosition pos root = go Nothing root
 findFoldingRanges :: CodeRange -> [FoldingRange]
 findFoldingRanges codeRange =
     -- removing the first node because it folds the entire file
-    drop 1 $ findFoldingRangesRec codeRange
+    drop1 $ findFoldingRangesRec codeRange
 
 findFoldingRangesRec :: CodeRange -> [FoldingRange]
 findFoldingRangesRec r@(CodeRange _ children _) =

plugins/hls-explicit-imports-plugin/src/Ide/Plugin/ExplicitImports.hs

@@ -316,7 +316,7 @@ abbreviateImportTitle input =
       oneLineText = T.unwords $ T.lines input
       -- Now, split at the max columns, leaving space for the summary text we're going to add
       -- (conservatively assuming we won't need to print a number larger than 100)
-      (prefix, suffix) = T.splitAt (maxColumns - (T.length (summaryText 100))) oneLineText
+      (prefix, suffix) = T.splitAt (maxColumns - T.length (summaryText 100)) oneLineText
       -- We also want to truncate the last item so we get a "clean" break, rather than half way through
       -- something. The conditional here is just because 'breakOnEnd' doesn't give us quite the right thing
       -- if there are actually no commas.

shake-bench/src/Development/Benchmark/Rules.hs

@@ -690,7 +690,7 @@ plotDiagram includeFailed t@Diagram {traceMetric, runLogs} out = do
                   ]
               ]
           return (lplot E.& E.plot_lines_style . E.line_width E.*~ 2)
-        case (runFirstReponse rl) of
+        case runFirstReponse rl of
           Just t -> E.plot $ pure $
               E.vlinePlot ("First build: " ++ runVersion rl) (E.defaultPlotLineStyle E.& E.line_color E..~ c) t
           _ -> pure ()