Follow hlint suggestions.

waspc/.gitignore

@@ -12,3 +12,5 @@ waspc.cabal
 .hie/
 .bin/
 stan.html
+
+*.orig

waspc/.hlint.yaml

@@ -1,14 +1,3 @@
-# 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]
 - arguments:
   # NOTE: List of extensions below should reflect the list
   #   of default extensions from package.yaml.
@@ -17,46 +6,11 @@
   - -XQuasiQuotes
   - -XScopedTypeVariables
 
-# 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
-
-
-# Add custom hints for this project
-#
-# Will suggest replacing "wibbleMany [myvar]" with "wibbleOne myvar"
-# - error: {lhs: "wibbleMany [x]", rhs: wibbleOne x}
-
-
-# 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 ~^#^~
+# TODO: Review the remaining ignored hlint rules.
+- ignore: {name: Use camelCase}
+- ignore: {name: Eta reduce}
+- ignore: {name: Use first} 
+- ignore: {name: Use second} 
+- ignore: {name: Use newtype instead of data} 
+- ignore: {name: Use $>} 
+- ignore: {name: Use list comprehension} 

waspc/cli/Main.hs

@@ -55,9 +55,9 @@ main = do
     Command.Call.Telemetry -> runCommand Telemetry.telemetry
     Command.Call.Deps -> runCommand deps
     Command.Call.Info -> runCommand info
-    Command.Call.PrintBashCompletionInstruction -> runCommand $ printBashCompletionInstruction
-    Command.Call.GenerateBashCompletionScript -> runCommand $ generateBashCompletionScript
-    Command.Call.BashCompletionListCommands -> runCommand $ bashCompletion
+    Command.Call.PrintBashCompletionInstruction -> runCommand printBashCompletionInstruction
+    Command.Call.GenerateBashCompletionScript -> runCommand generateBashCompletionScript
+    Command.Call.BashCompletionListCommands -> runCommand bashCompletion
     Command.Call.Unknown _ -> printUsage
 
   -- If sending of telemetry data is still not done 1 second since commmand finished, abort it.

waspc/cli/Wasp/Cli/Command/Common.hs

@@ -55,6 +55,5 @@ waspSaysC = liftIO . waspSays
 
 alphaWarningMessage :: String
 alphaWarningMessage =
-  ( "NOTE: Wasp is still in Alpha, therefore not yet production ready "
-      ++ "and might change significantly in the future versions."
-  )
+  "NOTE: Wasp is still in Alpha, therefore not yet production ready "
+    ++ "and might change significantly in the future versions."

waspc/cli/Wasp/Cli/Command/Db/Migrate.hs

@@ -97,12 +97,7 @@ copyDbMigrationsDir copyDirection waspProjectDir genProjectRootDir = do
   doesSrcDirExist <- PathIO.doesDirExist (SP.Path.toPathAbsDir src)
   if doesSrcDirExist
     then
-      ( ( PathIO.copyDirRecur
-            (SP.Path.toPathAbsDir src)
-            (SP.Path.toPathAbsDir target)
-        )
-          >> return Nothing
-      )
+      PathIO.copyDirRecur (SP.Path.toPathAbsDir src) (SP.Path.toPathAbsDir target) >> return Nothing
         `catch` (\e -> return $ Just $ show (e :: P.PathException))
         `catch` (\e -> return $ Just $ show (e :: IOError))
     else return Nothing

waspc/cli/Wasp/Cli/Command/Watch.hs

@@ -66,8 +66,8 @@ watch waspProjectDir outDir = FSN.withManager $ \mgr -> do
     eventFilter event =
       let filename = FP.takeFileName $ FSN.eventPath event
        in not (null filename)
-            && not (take 2 filename == ".#") -- Ignore emacs lock files.
+            && take 2 filename /= ".#" -- Ignore emacs lock files.
             && not (head filename == '#' && last filename == '#') -- Ignore emacs auto-save files.
-            && not (last filename == '~') -- Ignore emacs and vim backup files.
+            && last filename /= '~' -- Ignore emacs and vim backup files.
             && not (head filename == '.' && ".swp" `isSuffixOf` filename) -- Ignore vim swp files.
             && not (head filename == '.' && ".un~" `isSuffixOf` filename) -- Ignore vim undo files.

waspc/src/Wasp/Analyzer/Evaluator/TH/Decl.hs

@@ -144,7 +144,7 @@ genDictEntryTypesAndEvaluationForRecord :: Name -> [(Name, Type)] -> Q (ExpQ, Ex
 genDictEntryTypesAndEvaluationForRecord dataConstructorName fields =
   go $ reverse fields -- Reversing enables us to apply evaluations in right order.
   where
-    go [] = pure (listE [], varE 'pure `appE` conE dataConstructorName)
+    go [] = pure (listE [], [|pure|] `appE` conE dataConstructorName)
     go ((fieldName, fieldType) : restOfFields) = do
       (restDictType, restEvaluation) <- go restOfFields
       let thisDictTypeE =

waspc/src/Wasp/Analyzer/TypeChecker/Monad.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE TupleSections #-}
-
 module Wasp.Analyzer.TypeChecker.Monad
   ( TypeChecker,
     lookupType,

waspc/src/Wasp/Generator/DbGenerator.hs

@@ -6,7 +6,6 @@ module Wasp.Generator.DbGenerator
 where
 
 import Data.Aeson (object, (.=))
-import Data.Maybe (fromMaybe)
 import StrongPath (Dir, File', Path', Rel, reldir, relfile, (</>))
 import qualified StrongPath as SP
 import Wasp.CompileOptions (CompileOptions)
@@ -64,7 +63,7 @@ genPrismaSchema wasp = createTemplateFileDraft dstPath tmplSrcPath (Just templat
           "datasourceUrl" .= (datasourceUrl :: String)
         ]
 
-    dbSystem = fromMaybe Wasp.Db.SQLite $ Wasp.Db._system <$> Wasp.getDb wasp
+    dbSystem = maybe Wasp.Db.SQLite Wasp.Db._system (Wasp.getDb wasp)
     (datasourceProvider, datasourceUrl) = case dbSystem of
       Wasp.Db.PostgreSQL -> ("postgresql", "env(\"DATABASE_URL\")")
       -- TODO: Report this error with some better mechanism, not `error`.

waspc/src/Wasp/Generator/DockerGenerator.hs

@@ -13,11 +13,7 @@ import Wasp.Wasp (Wasp)
 import qualified Wasp.Wasp as Wasp
 
 genDockerFiles :: Wasp -> CompileOptions -> [FileDraft]
-genDockerFiles wasp _ =
-  concat
-    [ [genDockerfile wasp],
-      [genDockerignore wasp]
-    ]
+genDockerFiles wasp _ = genDockerfile wasp : [genDockerignore wasp]
 
 -- TODO: Inject paths to server and db files/dirs, right now they are hardcoded in the templates.
 genDockerfile :: Wasp -> FileDraft

waspc/src/Wasp/Generator/ServerGenerator.hs

@@ -7,7 +7,7 @@ module Wasp.Generator.ServerGenerator
   )
 where
 
-import Control.Monad (when)
+import Control.Monad (unless)
 import Data.Aeson (object, (.=))
 import Data.List (intercalate)
 import Data.Maybe
@@ -72,7 +72,7 @@ preCleanup _ outDir _ = do
   -- If .env gets removed but there is old .env file in generated project from previous attempts,
   -- we need to make sure we remove it.
   removeFile dotEnvAbsFilePath
-    `catch` \e -> when (not $ isDoesNotExistError e) $ throwIO e
+    `catch` \e -> unless (isDoesNotExistError e) $ throwIO e
   where
     dotEnvAbsFilePath = SP.toFilePath $ outDir </> C.serverRootDirInProjectRootDir </> dotEnvInServerRootDir
 
@@ -104,10 +104,11 @@ genPackageJson wasp waspDeps waspDevDeps =
             "devDepsChunk" .= npmDevDepsToPackageJsonEntry waspDevDeps,
             "nodeVersion" .= nodeVersionAsText,
             "startProductionScript"
-              .= concat
-                [ if not (null $ Wasp.getPSLEntities wasp) then "npm run db-migrate-prod && " else "",
-                  "NODE_ENV=production node ./src/server.js"
-                ]
+              .= if not (null $ Wasp.getPSLEntities wasp)
+                then "npm run db-migrate-prod && "
+                else
+                  ""
+                    ++ "NODE_ENV=production node ./src/server.js"
           ]
     )
   where

waspc/src/Wasp/Generator/ServerGenerator/OperationsG.hs

@@ -9,7 +9,7 @@ where
 import Data.Aeson (object, (.=))
 import qualified Data.Aeson as Aeson
 import Data.Char (toLower)
-import Data.Maybe (fromJust, fromMaybe)
+import Data.Maybe (fromJust)
 import StrongPath (Dir, Dir', File', Path, Path', Posix, Rel, reldir, reldirP, relfile, (</>))
 import qualified StrongPath as SP
 import Wasp.Generator.ExternalCodeGenerator.Common (GeneratedExternalCodeDir)
@@ -24,22 +24,16 @@ import qualified Wasp.Wasp.Query as Wasp.Query
 
 genOperations :: Wasp -> [FileDraft]
 genOperations wasp =
-  concat
-    [ genQueries wasp,
-      genActions wasp
-    ]
+  genQueries wasp
+    ++ genActions wasp
 
 genQueries :: Wasp -> [FileDraft]
 genQueries wasp =
-  concat
-    [ map (genQuery wasp) (Wasp.getQueries wasp)
-    ]
+  map (genQuery wasp) (Wasp.getQueries wasp)
 
 genActions :: Wasp -> [FileDraft]
 genActions wasp =
-  concat
-    [ map (genAction wasp) (Wasp.getActions wasp)
-    ]
+  map (genAction wasp) (Wasp.getActions wasp)
 
 -- | Here we generate JS file that basically imports JS query function provided by user,
 --   decorates it (mostly injects stuff into it) and exports. Idea is that the rest of the server,
@@ -86,7 +80,7 @@ operationTmplData operation =
   object
     [ "jsFnImportStatement" .= importStmt,
       "jsFnIdentifier" .= importIdentifier,
-      "entities" .= map buildEntityData (fromMaybe [] $ Wasp.Operation.getEntities operation)
+      "entities" .= maybe [] (map buildEntityData) (Wasp.Operation.getEntities operation)
     ]
   where
     (importIdentifier, importStmt) =

waspc/src/Wasp/Generator/WebAppGenerator.hs

@@ -116,8 +116,8 @@ generatePublicIndexHtml wasp =
     targetPath = [relfile|public/index.html|]
     templateData =
       object
-        [ "title" .= (Wasp.App.appTitle $ getApp wasp),
-          "head" .= (maybe "" (intercalate "\n") (Wasp.App.appHead $ getApp wasp))
+        [ "title" .= Wasp.App.appTitle (getApp wasp),
+          "head" .= maybe "" (intercalate "\n") (Wasp.App.appHead $ getApp wasp)
         ]
 
 -- * Src dir

waspc/src/Wasp/Generator/WebAppGenerator/AuthG.hs

@@ -45,8 +45,8 @@ genCreateAuthRequiredPage auth =
     (Just templateData)
   where
     authReqPagePath = [relfile|auth/pages/createAuthRequiredPage.js|]
-    targetPath = C.webAppSrcDirInWebAppRootDir </> (asWebAppSrcFile authReqPagePath)
-    templateData = object ["onAuthFailedRedirectTo" .= (Wasp.Auth._onAuthFailedRedirectTo auth)]
+    targetPath = C.webAppSrcDirInWebAppRootDir </> asWebAppSrcFile authReqPagePath
+    templateData = object ["onAuthFailedRedirectTo" .= Wasp.Auth._onAuthFailedRedirectTo auth]
 
 -- | Generates React hook that Wasp developer can use in a component to get
 --   access to the currently logged in user (and check whether user is logged in

waspc/src/Wasp/Generator/WebAppGenerator/OperationsGenerator.hs

@@ -8,10 +8,7 @@ import Data.Aeson
     (.=),
   )
 import Data.List (intercalate)
-import Data.Maybe
-  ( fromJust,
-    fromMaybe,
-  )
+import Data.Maybe (fromJust)
 import StrongPath (File', Path', Rel', parseRelFile, reldir, relfile, (</>))
 import Wasp.Generator.FileDraft (FileDraft)
 import qualified Wasp.Generator.ServerGenerator as ServerGenerator
@@ -35,16 +32,12 @@ genOperations wasp =
 
 genQueries :: Wasp -> [FileDraft]
 genQueries wasp =
-  concat
-    [ map (genQuery wasp) (Wasp.getQueries wasp),
-      [C.makeSimpleTemplateFD (C.asTmplFile [relfile|src/queries/index.js|]) wasp]
-    ]
+  map (genQuery wasp) (Wasp.getQueries wasp)
+    ++ [C.makeSimpleTemplateFD (C.asTmplFile [relfile|src/queries/index.js|]) wasp]
 
 genActions :: Wasp -> [FileDraft]
 genActions wasp =
-  concat
-    [ map (genAction wasp) (Wasp.getActions wasp)
-    ]
+  map (genAction wasp) (Wasp.getActions wasp)
 
 genQuery :: Wasp -> Wasp.Query.Query -> FileDraft
 genQuery _ query = C.makeTemplateFD tmplFile dstFile (Just tmplData)
@@ -87,7 +80,7 @@ genAction _ action = C.makeTemplateFD tmplFile dstFile (Just tmplData)
 makeJsArrayOfEntityNames :: Wasp.Operation.Operation -> String
 makeJsArrayOfEntityNames operation = "[" ++ intercalate ", " entityStrings ++ "]"
   where
-    entityStrings = map (\x -> "'" ++ x ++ "'") $ fromMaybe [] $ Wasp.Operation.getEntities operation
+    entityStrings = maybe [] (map (\x -> "'" ++ x ++ "'")) (Wasp.Operation.getEntities operation)
 
 getOperationDstFileName :: Wasp.Operation.Operation -> Maybe (Path' Rel' File')
 getOperationDstFileName operation = parseRelFile (Wasp.Operation.getName operation ++ ".js")

waspc/src/Wasp/Parser/Auth.hs

@@ -62,13 +62,13 @@ authProperty =
 
 authPropertyOnAuthFailedRedirectTo :: Parser AuthProperty
 authPropertyOnAuthFailedRedirectTo =
-  AuthPropertyOnAuthFailedRedirectTo <$> (P.waspPropertyStringLiteral "onAuthFailedRedirectTo")
+  AuthPropertyOnAuthFailedRedirectTo <$> P.waspPropertyStringLiteral "onAuthFailedRedirectTo"
 
 authPropertyUserEntity :: Parser AuthProperty
-authPropertyUserEntity = AuthPropertyUserEntity <$> (P.waspProperty "userEntity" L.identifier)
+authPropertyUserEntity = AuthPropertyUserEntity <$> P.waspProperty "userEntity" L.identifier
 
 authPropertyMethods :: Parser AuthProperty
 authPropertyMethods = AuthPropertyMethods <$> P.waspProperty "methods" (L.brackets $ L.commaSep1 authMethod)
 
 authMethod :: Parser Wasp.Auth.AuthMethod
-authMethod = L.symbol "EmailAndPassword" *> (pure Wasp.Auth.EmailAndPassword)
+authMethod = L.symbol "EmailAndPassword" *> pure Wasp.Auth.EmailAndPassword

waspc/src/Wasp/Parser/Db.hs

@@ -3,7 +3,7 @@ module Wasp.Parser.Db
   )
 where
 
-import Data.Maybe (fromMaybe, listToMaybe)
+import Data.Maybe (listToMaybe)
 import Text.Parsec (try, (<|>))
 import Text.Parsec.String (Parser)
 import qualified Wasp.Lexer as L
@@ -16,9 +16,10 @@ db = do
   dbProperties <- P.waspClosure (L.commaSep1 dbProperty)
 
   system <-
-    fromMaybe (fail "'system' property is required!") $
+    maybe
+      (fail "'system' property is required!")
       return
-        <$> listToMaybe [p | DbPropertySystem p <- dbProperties]
+      (listToMaybe [p | DbPropertySystem p <- dbProperties])
 
   return
     Wasp.Db.Db
@@ -33,7 +34,7 @@ dbProperty =
   dbPropertySystem
 
 dbPropertySystem :: Parser DbProperty
-dbPropertySystem = DbPropertySystem <$> (P.waspProperty "system" dbPropertySystemValue)
+dbPropertySystem = DbPropertySystem <$> P.waspProperty "system" dbPropertySystemValue
   where
     dbPropertySystemValue =
       try (L.symbol "PostgreSQL" >> return Wasp.Db.PostgreSQL)

waspc/src/Wasp/Parser/JsCode.hs

@@ -9,4 +9,4 @@ import qualified Wasp.Parser.Common as P
 import qualified Wasp.Wasp.JsCode as WJS
 
 jsCode :: Parser WJS.JsCode
-jsCode = (WJS.JsCode . Text.pack) <$> P.waspNamedClosure "js"
+jsCode = WJS.JsCode . Text.pack <$> P.waspNamedClosure "js"

waspc/src/Wasp/Parser/Style.hs

@@ -17,4 +17,4 @@ cssFile :: Parser Wasp.Style.Style
 cssFile = Wasp.Style.ExtCodeCssFile <$> Wasp.Parser.ExternalCode.extCodeFilePathString
 
 cssCode :: Parser Wasp.Style.Style
-cssCode = (Wasp.Style.CssCode . Text.pack) <$> Wasp.Parser.Common.waspNamedClosure "css"
+cssCode = Wasp.Style.CssCode . Text.pack <$> Wasp.Parser.Common.waspNamedClosure "css"