HLint fails to parse code that is invalid in disabled extensions

[maksbotan]

Your environment

Output of haskell-language-server --probe-tools or haskell-language-server-wrapper --probe-tools:

$ haskell-language-server-wrapper --probe-tools
haskell-language-server version: 0.9.0.0 (GHC: 8.10.1) (PATH: /Users/maksbotan/.local/bin/haskell-language-server-wrapper) (GIT hash: 46d2a3dc7ef49ba57b2706022af1801149ab3f2b)
Tool versions found on the $PATH
cabal:		3.2.0.0
stack:		2.5.1
ghc:		8.8.4

Which lsp-client do you use:

vim version: NVIM v0.4.4
node version: v14.15.0
coc.nvim version: 0.0.80-50544406f0

Describe your project (alternative: link to the project):

module Foo (pattern) where

pattern = 42

Steps to reproduce

Open the above module.

Expected behaviour

No errors.

Actual behaviour

[hlint parser] [I] parse error on input `)'
> module Foo (pattern) where
  
  pattern = 42

Include debug information

Execute in the root of your project the command haskell-language-server --debug . and paste the logs here:

Debug output:

$ haskell-language-server-8.8.4 --debug ptrn.hs
haskell-language-server version: 0.9.0.0 (GHC: 8.8.4) (PATH: /Users/maksbotan/.local/bin/haskell-language-server-8.8.4) (GIT hash: 46d2a3dc7ef49ba57b2706022af1801149ab3f2b)
(haskell-language-server)Ghcide setup tester in /Users/maksbotan/temp.
Report bugs at https://github.com/haskell/haskell-language-server/issues

Tool versions found on the $PATH
cabal:		3.2.0.0
stack:		2.5.1
ghc:		8.8.4


Step 1/4: Finding files to test in /Users/maksbotan/temp
Found 1 files

Step 2/4: Looking for hie.yaml files that control setup
Found 1 cradle

Step 3/4: Initializing the IDE

Step 4/4: Type checking the files
[INFO] Consulting the cradle for "ptrn.hs"
NotShowMessage (NotificationMessage {_jsonrpc = "2.0", _method = WindowShowMessage, _params = ShowMessageParams {_xtype = MtInfo, _message = "No [cradle](https://github.com/mpickering/hie-bios#hie-bios) found for ptrn.hs.\n Proceeding with [implicit cradle](https://hackage.haskell.org/package/implicit-hie).\nYou should ignore this message, unless you see a 'Multi Cradle: No prefixes matched' error."}})
Output from setting up the cradle Cradle {cradleRootDir = "/Users/maksbotan/temp", cradleOptsProg = CradleAction: Default}
Loaded package environment from /Users/maksbotan/.ghc/x86_64-darwin-8.8.4/environments/default
[INFO] Using interface files cache dir: ghcide
[INFO] Making new HscEnv[main]

[INFO] finish: User TypeCheck (took 0.02s)
Completed (1 file worked, 0 files failed)

Paste the logs from the lsp-client, e.g. for VS Code

LSP logs:

haskell-lsp:Starting up server ...
2021-01-31 14:59:49.327691 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":89104,"rootPath":"/Users/maksbotan/temp","rootUri":"file:///Users/maksbotan/temp","capabilities":{"workspace":{"applyEdit":true,"workspaceEdit":{"documentChanges":true,"resourceOperations":["create","rename","delete"],"failureHandling":"textOnlyTransactional"},"didChangeConfiguration":{"dynamicRegistration":true},"didChangeWatchedFiles":{"dynamicRegistration":true},"symbol":{"dynamicRegistration":true,"symbolKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]},"tagSupport":{"valueSet":[1]}},"executeCommand":{"dynamicRegistration":true},"configuration":true,"workspaceFolders":true},"textDocument":{"publishDiagnostics":{"relatedInformation":true,"versionSupport":false,"tagSupport":{"valueSet":[1,2]}},"synchronization":{"dynamicRegistration":true,"willSave":true,"willSaveWaitUntil":true,"didSave":true},"completion":{"dynamicRegistration":true,"contextSupport":true,"completionItem":{"snippetSupport":true,"commitCharactersSupport":true,"documentationFormat":["markdown","plaintext"],"deprecatedSupport":true,"preselectSupport":true,"tagSupport":{"valueSet":[1]}},"completionItemKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]}},"hover":{"dynamicRegistration":true,"contentFormat":["markdown","plaintext"]},"signatureHelp":{"dynamicRegistration":true,"contextSupport":true,"signatureInformation":{"documentationFormat":["markdown","plaintext"],"activeParameterSupport":true,"parameterInformation":{"labelOffsetSupport":true}}},"definition":{"dynamicRegistration":true},"references":{"dynamicRegistration":true},"documentHighlight":{"dynamicRegistration":true},"documentSymbol":{"dynamicRegistration":true,"symbolKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]},"hierarchicalDocumentSymbolSupport":true,"tagSupport":{"valueSet":[1]}},"codeAction":{"dynamicRegistration":true,"isPreferredSupport":true,"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["","quickfix","refactor","refactor.extract","refactor.inline","refactor.rewrite","source","source.organizeImports"]}}},"codeLens":{"dynamicRegistration":true},"formatting":{"dynamicRegistration":true},"rangeFormatting":{"dynamicRegistration":true},"onTypeFormatting":{"dynamicRegistration":true},"rename":{"dynamicRegistration":true,"prepareSupport":true},"documentLink":{"dynamicRegistration":true,"tooltipSupport":true},"typeDefinition":{"dynamicRegistration":true},"implementation":{"dynamicRegistration":true},"declaration":{"dynamicRegistration":true},"colorProvider":{"dynamicRegistration":true},"foldingRange":{"dynamicRegistration":true,"rangeLimit":5000,"lineFoldingOnly":true},"selectionRange":{"dynamicRegistration":true}},"window":{"workDoneProgress":true}},"initializationOptions":{},"trace":"off","workspaceFolders":[{"uri":"file:///Users/maksbotan/temp","name":"temp"}],"clientInfo":{"name":"coc.nvim","version":"0.0.80"},"workDoneToken":"14fa7786-9eb5-4307-8679-932487a81e4d"}}
2021-01-31 14:59:49.328639 [ThreadId 5] - haskell-lsp:initializeRequestHandler: setting current dir to project root:/Users/maksbotan/temp
2021-01-31 14:59:49.329466 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"type":1,"message":"haskell-lsp:configuration parse error. RequestMessage {_jsonrpc = \"2.0\", _id = IdInt 0, _method = Initialize, _params = InitializeParams {_processId = Just 89104, _rootPath = Just \"/Users/maksbotan/temp\", _rootUri = Just (Uri {getUri = \"file:///Users/maksbotan/temp\"}), _initializationOptions = Just (Object (fromList [])), _capabilities = ClientCapabilities {_workspace = Just (WorkspaceClientCapabilities {_applyEdit = Just True, _workspaceEdit = Just (WorkspaceEditClientCapabilities {_documentChanges = Just True}), _didChangeConfiguration = Just (DidChangeConfigurationClientCapabilities {_dynamicRegistration = Just True}), _didChangeWatchedFiles = Just (DidChangeWatchedFilesClientCapabilities {_dynamicRegistration = Just True}), _symbol = Just (SymbolClientCapabilities {_dynamicRegistration = Just True, _symbolKind = Just (SymbolKindClientCapabilities {_valueSet = Just (List [SkFile,SkModule,SkNamespace,SkPackage,SkClass,SkMethod,SkProperty,SkField,SkConstructor,SkEnum,SkInterface,SkFunction,SkVariable,SkConstant,SkString,SkNumber,SkBoolean,SkArray,SkObject,SkKey,SkNull,SkEnumMember,SkStruct,SkEvent,SkOperator,SkTypeParameter])})}), _executeCommand = Just (ExecuteClientCapabilities {_dynamicRegistration = Just True}), _workspaceFolders = Just True, _configuration = Just True}), _textDocument = Just (TextDocumentClientCapabilities {_synchronization = Just (SynchronizationTextDocumentClientCapabilities {_dynamicRegistration = Just True, _willSave = Just True, _willSaveWaitUntil = Just True, _didSave = Just True}), _completion = Just (CompletionClientCapabilities {_dynamicRegistration = Just True, _completionItem = Just (CompletionItemClientCapabilities {_snippetSupport = Just True, _commitCharactersSupport = Just True, _documentationFormat = Just (List [MkMarkdown,MkPlainText]), _deprecatedSupport = Just True, _preselectSupport = Just True, _tagSupport = Just (CompletionItemTagsClientCapabilities {_valueSet = List [CtDeprecated]})}), _completionItemKind = Just (CompletionItemKindClientCapabilities {_valueSet = Just (List [CiText,CiMethod,CiFunction,CiConstructor,CiField,CiVariable,CiClass,CiInterface,CiModule,CiProperty,CiUnit,CiValue,CiEnum,CiKeyword,CiSnippet,CiColor,CiFile,CiReference,CiFolder,CiEnumMember,CiConstant,CiStruct,CiEvent,CiOperator,CiTypeParameter])}), _contextSupport = Just True}), _hover = Just (HoverClientCapabilities {_dynamicRegistration = Just True, _contentFormat = Just (List [MkMarkdown,MkPlainText])}), _signatureHelp = Just (SignatureHelpClientCapabilities {_dynamicRegistration = Just True, _signatureInformation = Just (SignatureInformationClientCapabilities {documentationFormat = Nothing})}), _references = Just (ReferencesClientCapabilities {_dynamicRegistration = Just True}), _documentHighlight = Just (DocumentHighlightClientCapabilities {_dynamicRegistration = Just True}), _documentSymbol = Just (DocumentSymbolClientCapabilities {_dynamicRegistration = Just True, _symbolKind = Just (DocumentSymbolKindClientCapabilities {_valueSet = Just (List [SkFile,SkModule,SkNamespace,SkPackage,SkClass,SkMethod,SkProperty,SkField,SkConstructor,SkEnum,SkInterface,SkFunction,SkVariable,SkConstant,SkString,SkNumber,SkBoolean,SkArray,SkObject,SkKey,SkNull,SkEnumMember,SkStruct,SkEvent,SkOperator,SkTypeParameter])}), _hierarchicalDocumentSymbolSupport = Just True}), _formatting = Just (FormattingClientCapabilities {_dynamicRegistration = Just True}), _rangeFormatting = Just (RangeFormattingClientCapabilities {_dynamicRegistration = Just True}), _onTypeFormatting = Just (OnTypeFormattingClientCapabilities {_dynamicRegistration = Just True}), _definition = Just (DefinitionClientCapabilities {_dynamicRegistration = Just True}), _typeDefinition = Just (TypeDefinitionClientCapabilities {_dynamicRegistration = Just True}), _implementation = Just (ImplementationClientCapabilities {_dynamicRegistration = Just True}), _codeAction = Just (CodeActionClientCapabilities {_dynamicRegistration = Just True, _codeActionLiteralSupport = Just (CodeActionLiteralSupport {_codeActionKind = CodeActionKindClientCapabilities {_valueSet = List [CodeActionUnknown \"\",CodeActionQuickFix,CodeActionRefactor,CodeActionRefactorExtract,CodeActionRefactorInline,CodeActionRefactorRewrite,CodeActionSource,CodeActionSourceOrganizeImports]}})}), _codeLens = Just (CodeLensClientCapabilities {_dynamicRegistration = Just True}), _documentLink = Just (DocumentLinkClientCapabilities {_dynamicRegistration = Just True}), _colorProvider = Just (ColorProviderClientCapabilities {_dynamicRegistration = Just True}), _rename = Just (RenameClientCapabilities {_dynamicRegistration = Just True, _prepareSupport = Just True}), _publishDiagnostics = Just (PublishDiagnosticsClientCapabilities {_relatedInformation = Just True, _tagSupport = Just (PublishDiagnosticsTagsClientCapabilities {_valueSet = List [DtUnnecessary,DtDeprecated]})}), _foldingRange = Just (FoldingRangeClientCapabilities {_dynamicRegistration = Just True, _rangeLimit = Just 5000, _lineFoldingOnly = Just True})}), _window = Just (WindowClientCapabilities {_workDoneProgress = Just True}), _experimental = Nothing}, _trace = Just TraceOff, _workspaceFolders = Just (List [WorkspaceFolder {_uri = \"file:///Users/maksbotan/temp\", _name = \"temp\"}])}} \"key \\\"languageServerHaskell\\\" not found\""},"method":"window/logMessage"}
2021-01-31 14:59:49.503625 [ThreadId 21] - Registering ide configuration: IdeConfiguration {workspaceFolders = fromList [NormalizedUri (-5617253724344668367) "file:///Users/maksbotan/temp"], clientSettings = hashed (Just (Object (fromList [])))}
2021-01-31 14:59:49.50386 [ThreadId 7] - <--2--{"result":{"capabilities":{"typeDefinitionProvider":true,"foldingRangeProvider":false,"textDocumentSync":{"openClose":true,"change":2,"save":{}},"workspace":{"workspaceFolders":{"supported":true,"changeNotifications":true}},"implementationProvider":true,"documentRangeFormattingProvider":true,"documentHighlightProvider":true,"executeCommandProvider":{"commands":["89114:class:addMinimalMethodPlaceholders","89114:eval:evalCommand","89114:ghcide-type-lenses:typesignature.add","89114:hlint:applyOne","89114:hlint:applyAll","89114:importLens:ImportLensCommand","89114:moduleName:edit","89114:retrie:retrieCommand","89114:splice:expandTHSpliceInplace","89114:tactic:tacticsAutoCommand","89114:tactic:tacticsIntrosCommand","89114:tactic:tacticsDestructCommand","89114:tactic:tacticsHomomorphismCommand","89114:tactic:tacticsDestructLambdaCaseCommand","89114:tactic:tacticsHomomorphismLambdaCaseCommand"]},"renameProvider":false,"colorProvider":false,"definitionProvider":true,"hoverProvider":true,"codeActionProvider":true,"completionProvider":{"triggerCharacters":["."],"resolveProvider":false},"codeLensProvider":{},"documentSymbolProvider":true,"documentFormattingProvider":true}},"jsonrpc":"2.0","id":0}
2021-01-31 14:59:49.50522 [ThreadId 5] - ---> {"jsonrpc":"2.0","method":"initialized","params":{}}
2021-01-31 14:59:49.505517 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"registrations":[{"registerOptions":{"watchers":[{"kind":5,"globPattern":"**/*.hs"},{"kind":5,"globPattern":"**/*.hs-boot"},{"kind":5,"globPattern":"**/*.lhs"},{"kind":5,"globPattern":"**/*.lhs-boot"}]},"method":"workspace/didChangeWatchedFiles","id":"globalFileWatches"}]},"method":"client/registerCapability","id":0}
2021-01-31 14:59:49.505886 [ThreadId 5] - ---> {"jsonrpc":"2.0","method":"workspace/didChangeConfiguration","params":{"settings":{"haskell":{"formattingProvider":"stylish-haskell","completionSnippetsOn":false}}}}
2021-01-31 14:59:49.50604 [ThreadId 21] - Configuration changed: Object (fromList [("haskell",Object (fromList [("completionSnippetsOn",Bool False),("formattingProvider",String "stylish-haskell")]))])
2021-01-31 14:59:49.506209 [ThreadId 20] - Finishing build session(exception: AsyncCancelled)
2021-01-31 14:59:49.50627 [ThreadId 21] - Restarting build session (aborting the previous one took 0.00s)
2021-01-31 14:59:49.506372 [ThreadId 5] - ---> {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///Users/maksbotan/temp/ptrn.hs","languageId":"haskell","version":1,"text":"module Foo (pattern) where\n\npattern = 42\n"}}}
2021-01-31 14:59:49.506591 [ThreadId 21] - Set files of interest to: [(NormalizedFilePath "/Users/maksbotan/temp/ptrn.hs",Modified)]
2021-01-31 14:59:49.506767 [ThreadId 21] - Restarting build session (aborting the previous one took 0.00s)
2021-01-31 14:59:49.506746 [ThreadId 40] - Finishing build session(exception: AsyncCancelled)
2021-01-31 14:59:49.506875 [ThreadId 21] - Opened text document: file:///Users/maksbotan/temp/ptrn.hs
2021-01-31 14:59:49.507473 [ThreadId 91] - hlint:getIdeas:file:NormalizedFilePath "/Users/maksbotan/temp/ptrn.hs"
2021-01-31 14:59:49.508655 [ThreadId 97] - Consulting the cradle for "ptrn.hs"
2021-01-31 14:59:49.508864 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"type":3,"message":"No [cradle](https://github.com/mpickering/hie-bios#hie-bios) found for ptrn.hs.\n Proceeding with [implicit cradle](https://hackage.haskell.org/package/implicit-hie).\nYou should ignore this message, unless you see a 'Multi Cradle: No prefixes matched' error."},"method":"window/showMessage"}
2021-01-31 14:59:49.513688 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":0,"result":null}
2021-01-31 14:59:49.513831 [ThreadId 5] - haskell-lsp:Got reply message:"{\"jsonrpc\":\"2.0\",\"id\":0,\"result\":null}"
2021-01-31 14:59:49.526888 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"token":0},"method":"window/workDoneProgress/create","id":1}
2021-01-31 14:59:49.527022 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"value":{"kind":"begin","cancellable":false,"title":"Setting up temp (for ptrn.hs)"},"token":0},"method":"$/progress"}
2021-01-31 14:59:49.527747 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":1,"result":null}
2021-01-31 14:59:49.527877 [ThreadId 5] - haskell-lsp:Got reply message:"{\"jsonrpc\":\"2.0\",\"id\":1,\"result\":null}"
2021-01-31 14:59:49.608357 [ThreadId 97] - Session loading result: Right (ComponentOptions {componentOptions = [], componentRoot = "/Users/maksbotan/temp", componentDependencies = []},"/nix/store/9rirdmvjbxiic7g38jhx7gmr15nnj5z7-ghc-8.8.4/lib/ghc-8.8.4")
2021-01-31 14:59:49.608423 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"value":{"kind":"end"},"token":0},"method":"$/progress"}
2021-01-31 14:59:49.611717 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"token":"24"},"method":"window/workDoneProgress/create","id":2}
2021-01-31 14:59:49.611842 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"value":{"kind":"begin","title":"Processing"},"token":"24"},"method":"$/progress"}
2021-01-31 14:59:49.612351 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":2,"result":null}
2021-01-31 14:59:49.612428 [ThreadId 5] - haskell-lsp:Got reply message:"{\"jsonrpc\":\"2.0\",\"id\":2,\"result\":null}"
2021-01-31 14:59:49.673494 [ThreadId 97] - Using interface files cache dir: ghcide
2021-01-31 14:59:49.673588 [ThreadId 97] - Making new HscEnv[main]
2021-01-31 14:59:49.682998 [ThreadId 97] - New Component Cache HscEnvEq: (([],Just HscEnvEq 25),fromList [])
2021-01-31 14:59:49.683147 [ThreadId 97] - Known files updated: fromList [(TargetFile NormalizedFilePath "/Users/maksbotan/temp/ptrn.hs",["/Users/maksbotan/temp/ptrn.hs"])]
2021-01-31 14:59:49.683398 [ThreadId 97] - Restarting build session (aborting the previous one took 0.00s)
2021-01-31 14:59:49.68355 [ThreadId 62] - Finishing build session(exception: AsyncCancelled)
2021-01-31 14:59:49.684888 [ThreadId 148] - hlint:getIdeas:file:NormalizedFilePath "/Users/maksbotan/temp/ptrn.hs"
2021-01-31 14:59:49.686447 [ThreadId 177] - hlint:getIdeas:setExtensions:[Cpp,OverlappingInstances,UndecidableInstances,IncoherentInstances,UndecidableSuperClasses,MonomorphismRestriction,MonoPatBinds,MonoLocalBinds,RelaxedPolyRec,ExtendedDefaultRules,ForeignFunctionInterface,UnliftedFFITypes,InterruptibleFFI,CApiFFI,GHCForeignImportPrim,JavaScriptFFI,ParallelArrays,TemplateHaskell,TemplateHaskellQuotes,ImplicitParams,ImplicitPrelude,ScopedTypeVariables,AllowAmbiguousTypes,UnliftedNewtypes,BangPatterns,TypeFamilies,TypeFamilyDependencies,TypeInType,OverloadedStrings,OverloadedLists,NumDecimals,DisambiguateRecordFields,RecordWildCards,RecordPuns,ViewPatterns,GADTs,GADTSyntax,NPlusKPatterns,DoAndIfThenElse,BlockArguments,RebindableSyntax,ConstraintKinds,PolyKinds,DataKinds,InstanceSigs,ApplicativeDo,StandaloneDeriving,DeriveDataTypeable,AutoDeriveTypeable,DeriveFunctor,DeriveTraversable,DeriveFoldable,DeriveGeneric,DefaultSignatures,DeriveAnyClass,DeriveLift,DerivingStrategies,DerivingVia,TypeSynonymInstances,FlexibleContexts,FlexibleInstances,ConstrainedClassMethods,MultiParamTypeClasses,NullaryTypeClasses,FunctionalDependencies,UnicodeSyntax,ExistentialQuantification,MagicHash,EmptyDataDecls,KindSignatures,RoleAnnotations,ParallelListComp,MonadComprehensions,GeneralizedNewtypeDeriving,PostfixOperators,TupleSections,PatternGuards,LiberalTypeSynonyms,RankNTypes,ImpredicativeTypes,TypeOperators,ExplicitNamespaces,PackageImports,ExplicitForAll,AlternativeLayoutRuleTransitional,DatatypeContexts,NondecreasingIndentation,RelaxedLayout,TraditionalRecordSyntax,LambdaCase,MultiWayIf,BinaryLiterals,HexFloatLiterals,DuplicateRecordFields,OverloadedLabels,EmptyCase,PatternSynonyms,PartialTypeSignatures,NamedWildCards,TypeApplications,Strict,StrictData,MonadFailDesugaring,EmptyDataDeriving,NumericUnderscores,QuantifiedConstraints,ImportQualifiedPost,CUSKs,StandaloneKindSignatures,StarIsType]
2021-01-31 14:59:49.687662 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"uri":"file:///Users/maksbotan/temp/ptrn.hs","diagnostics":[{"severity":3,"range":{"start":{"line":0,"character":19},"end":{"line":0,"character":20}},"code":"parser","source":"hlint","message":"parse error on input `)'\n> module Foo (pattern) where\n  \n  pattern = 42\n\n"}]},"method":"textDocument/publishDiagnostics"}
2021-01-31 14:59:49.710085 [ThreadId 7] - <--2--{"jsonrpc":"2.0","params":{"value":{"kind":"end"},"token":"24"},"method":"$/progress"}
2021-01-31 14:59:49.710318 [ThreadId 211] - finish: InitialLoad (took 0.03s)
2021-01-31 14:59:52.752043 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":1,"method":"textDocument/codeLens","params":{"textDocument":{"uri":"file:///Users/maksbotan/temp/ptrn.hs"}}}
2021-01-31 14:59:52.752483 [ThreadId 214] - Plugin.makeCodeLens (ideLogger)
2021-01-31 14:59:52.752867 [ThreadId 215] - src/Ide/Plugin/Eval/CodeLens.hs:239:15 "fp" "/Users/maksbotan/temp/ptrn.hs"
2021-01-31 14:59:52.753114 [ThreadId 223] - finish: codeLens (took 0.00s)
2021-01-31 14:59:52.753623 [ThreadId 225] - finish: ModuleName.GetParsedModule (took 0.00s)
2021-01-31 14:59:52.753705 [ThreadId 230] - finish: getSession (took 0.00s)
2021-01-31 14:59:52.753881 [ThreadId 232] - finish:  (took 0.00s)
2021-01-31 14:59:52.753949 [ThreadId 215] - src/Ide/Plugin/Eval/CodeLens.hs:239:15 "preprocessor" "0.00s"
2021-01-31 14:59:52.754222 [ThreadId 215] - src/Ide/Plugin/Eval/CodeLens.hs:239:15 "Tests" "0 tests in 0 sections 0 setups 0 lenses."
2021-01-31 14:59:52.754462 [ThreadId 215] - src/Ide/Plugin/Eval/CodeLens.hs:239:15 "tests" "0.00s"
2021-01-31 14:59:52.754603 [ThreadId 215] - src/Ide/Plugin/Eval/CodeLens.hs:239:15 "codeLens" "0.00s"
2021-01-31 14:59:52.755225 [ThreadId 7] - <--2--{"result":[{"command":{"command":"89114:ghcide-type-lenses:typesignature.add","arguments":[{"changes":{"file:///Users/maksbotan/temp/ptrn.hs":[{"range":{"start":{"line":2,"character":0},"end":{"line":2,"character":0}},"newText":"pattern :: Integer\n"}]}}],"title":"pattern :: Integer"},"range":{"start":{"line":2,"character":0},"end":{"line":2,"character":7}}},{"command":{"command":"89114:moduleName:edit","arguments":["file:///Users/maksbotan/temp/ptrn.hs"],"title":"Set module name to Main"},"range":{"start":{"line":0,"character":7},"end":{"line":0,"character":10}}}],"jsonrpc":"2.0","id":1}
2021-01-31 14:59:52.75782 [ThreadId 5] - ---> {"jsonrpc":"2.0","id":2,"method":"textDocument/documentHighlight","params":{"textDocument":{"uri":"file:///Users/maksbotan/temp/ptrn.hs"},"position":{"line":0,"character":0}}}
2021-01-31 14:59:52.758247 [ThreadId 236] - DocumentHighlight request at position 1:1 in file: /Users/maksbotan/temp/ptrn.hs
2021-01-31 14:59:52.758606 [ThreadId 237] - finish: C:GetHieAst (took 0.00s)
2021-01-31 14:59:52.758715 [ThreadId 7] - <--2--{"result":[],"jsonrpc":"2.0","id":2}
2021-01-31 14:59:53.31644 [ThreadId 5] - ---> {"jsonrpc":"2.0","method":"textDocument/didClose","params":{"textDocument":{"uri":"file:///Users/maksbotan/temp/ptrn.hs"}}}
2021-01-31 14:59:53.316814 [ThreadId 5] - Closed: Uri {getUri = "file:///Users/maksbotan/temp/ptrn.hs"}
2021-01-31 14:59:53.317118 [ThreadId 21] - Set files of interest to: []
2021-01-31 14:59:53.317316 [ThreadId 21] - Closed text document: file:///Users/maksbotan/temp/ptrn.hs
2021-01-31 14:59:53.317567 [ThreadId 240] - Typechecking reverse dependencies for NormalizedFilePath "/Users/maksbotan/temp/ptrn.hs": Just []
2021-01-31 14:59:53.317712 [ThreadId 240] - finish: ParentTC (took 0.00s)

As you can see, HLS enables all extensions for HLint, including PatternSynonyms, which makes pattern a reserved keyword. I, however, do not enable it in my Haskell source and am free to use it as I like. Therefore HLint is broken for this file.

[jneira]

@maksbotan yeah, hlint enables by default a bunch of extensions known to be relatively innocuous, but in this (somewhat corner?) case it cant parse the module.
I guess if you uses hlint directly in the cli it behaves in a similar way, or doesnt?

[maksbotan]

Yeah, you are right. I've never used HLint on its own, so wasn't aware of this.

$ hlint --version
HLint v3.2.7, (C) Neil Mitchell 2006-2021
$ hlint ptrn.hs 
ptrn.hs:1:20: Error: Parse error: on input `)'
Found:
  > module Foo (pattern) where
    
    pattern = 42
  

1 hint

[maksbotan]

Would it make sense to make HLint explicitly enable the same set of extensions as passed to GHC for the current module?

[jneira]

yeah, in fact we are doing it already and we only should remove the default extensions used by hlint
we have to analyze if it can have unintended effects

[jneira]

This has a regression tes here:

haskell-language-server/plugins/hls-hlint-plugin/test/Main.hs

Lines 215 to 221 in 95de49b

	, knownBrokenForHlintOnGhcLib "[#1279] hlint uses a fixed set of extensions" $
	testCase "hlint should not activate extensions like PatternSynonyms" $ runHlintSession "" $ do
	doc <- openDoc "PatternKeyword.hs" "haskell"
	waitForAllProgressDone
	-- hlint will report a parse error if PatternSynonyms is enabled
	expectNoMoreDiagnostics 3 doc "hlint"

[jneira]

@eddiemundo do you think this could relativley easy to fix?