helix errors out on lsp initialization

[jdrst]

hi,

i'm trying to take the new roslyn languageserver for a spin.
unfortunately helix throws an error during initialization.
here are some respective logs entries:

2023-07-01T09:24:40.623 helix_lsp::transport [INFO] roslyn -> {"jsonrpc":"2.0","method":"initialize","params":{"capabilities":{"general":{"positionEncodings":["utf-8","utf-32","utf-16"]},"textDocument":{"codeAction":{"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["","quickfix","refactor","refactor.extract","refactor.inline","refactor.rewrite","source","source.organizeImports"]}}},"completion":{"completionItem":{"deprecatedSupport":true,"insertReplaceSupport":true,"resolveSupport":{"properties":["documentation","detail","additionalTextEdits"]},"snippetSupport":true,"tagSupport":{"valueSet":[1]}},"completionItemKind":{}},"hover":{"contentFormat":["markdown"]},"inlayHint":{"dynamicRegistration":false},"publishDiagnostics":{"versionSupport":true},"rename":{"dynamicRegistration":false,"honorsChangeAnnotations":false,"prepareSupport":true},"signatureHelp":{"signatureInformation":{"activeParameterSupport":true,"documentationFormat":["markdown"],"parameterInformation":{"labelOffsetSupport":true}}}},"window":{"workDoneProgress":true},"workspace":{"applyEdit":true,"configuration":true,"didChangeConfiguration":{"dynamicRegistration":false},"executeCommand":{"dynamicRegistration":false},"inlayHint":{"refreshSupport":false},"symbol":{"dynamicRegistration":false},"workspaceEdit":{"documentChanges":true,"failureHandling":"abort","normalizesLineEndings":false,"resourceOperations":["create","rename","delete"]},"workspaceFolders":true}},"clientInfo":{"name":"helix","version":"23.05 (9546e0c0)"},"processId":17627,"rootPath":"/home/jd/git/dotnet-init","rootUri":null,"workspaceFolders":[]},"id":0}
[..]
2023-07-01T09:24:41.412 helix_lsp::transport [ERROR] roslyn err <- "info: LanguageServerHost[0]\n"
2023-07-01T09:24:41.412 helix_lsp::transport [ERROR] roslyn err <- "      Starting server...\n"
[..]
2023-07-01T09:24:41.631 helix_lsp::transport [INFO] roslyn <- {"jsonrpc":"2.0","id":0,"result":{"capabilities":{"_vs_onAutoInsertProvider":{"_vs_triggerCharacters":["'","/","\n"]},"textDocumentSync":{"openClose":true,"change":2},"completionProvider":{"triggerCharacters":["\"","(",":","[","\\","{","#",".",">"," ","~","<"],"allCommitCharacters":[" ","{","}","[","]","(",")",".",",",":",";","+","-","*","/","%","&","|","^","!","~","=","<",">","?","@","#","'","\"","\\"],"resolveProvider":true},"hoverProvider":true,"signatureHelpProvider":{"triggerCharacters":["(",","]},"definitionProvider":true,"implementationProvider":true,"referencesProvider":{"workDoneProgress":true},"documentHighlightProvider":true,"documentSymbolProvider":true,"codeActionProvider":{"codeActionKinds":["quickfix","refactor"],"resolveProvider":true},"codeLensProvider":{"resolveProvider":true},"documentFormattingProvider":true,"documentRangeFormattingProvider":true,"documentOnTypeFormattingProvider":{"firstTriggerCharacter":"}","moreTriggerCharacter":[";","\n"]},"renameProvider":true,"foldingRangeProvider":true,"executeCommandProvider":{},"workspaceSymbolProvider":true,"semanticTokensProvider":{"legend":{"tokenTypes":["namespace","type","class","enum","interface","struct","typeParameter","parameter","variable","property","enumMember","event","function","method","macro","keyword","modifier","comment","string","number","regexp","operator","constant","controlKeyword","delegate","excludedCode","extensionMethod","field","jsonArray","jsonComment","jsonConstructorName","jsonKeyword","jsonNumber","jsonObject","jsonOperator","jsonPropertyName","jsonPunctuation","jsonString","jsonText","label","module","operatorOverloaded","preprocessorText","punctuation","recordClass","recordStruct","regexAlternation","regexAnchor","regexCharacterClass","regexComment","regexGrouping","regexOtherEscape","regexQuantifier","regexSelfEscapedCharacter","regexText","stringEscapeCharacter","stringVerbatim","text","whitespace","xmlDocCommentAttributeName","xmlDocCommentAttributeQuotes","xmlDocCommentAttributeValue","xmlDocCommentCDataSection","xmlDocCommentComment","xmlDocCommentDelimiter","xmlDocCommentEntityReference","xmlDocCommentName","xmlDocCommentProcessingInstruction","xmlDocCommentText","xmlLiteralAttributeName","xmlLiteralAttributeQuotes","xmlLiteralAttributeValue","xmlLiteralCDataSection","xmlLiteralComment","xmlLiteralDelimiter","xmlLiteralEmbeddedExpression","xmlLiteralEntityReference","xmlLiteralName","xmlLiteralProcessingInstruction","xmlLiteralText"],"tokenModifiers":["static","ReassignedVariable"]},"range":true,"full":false},"diagnosticProvider":{"workDoneProgress":true,"interFileDependencies":true,"workspaceDiagnostics":true},"inlayHintProvider":{"resolveProvider":true}}}}
2023-07-01T09:24:41.631 helix_lsp::transport [INFO] roslyn <- {"capabilities":{"_vs_onAutoInsertProvider":{"_vs_triggerCharacters":["'","/","\n"]},"codeActionProvider":{"codeActionKinds":["quickfix","refactor"],"resolveProvider":true},"codeLensProvider":{"resolveProvider":true},"completionProvider":{"allCommitCharacters":[" ","{","}","[","]","(",")",".",",",":",";","+","-","*","/","%","&","|","^","!","~","=","<",">","?","@","#","'","\"","\\"],"resolveProvider":true,"triggerCharacters":["\"","(",":","[","\\","{","#",".",">"," ","~","<"]},"definitionProvider":true,"diagnosticProvider":{"interFileDependencies":true,"workDoneProgress":true,"workspaceDiagnostics":true},"documentFormattingProvider":true,"documentHighlightProvider":true,"documentOnTypeFormattingProvider":{"firstTriggerCharacter":"}","moreTriggerCharacter":[";","\n"]},"documentRangeFormattingProvider":true,"documentSymbolProvider":true,"executeCommandProvider":{},"foldingRangeProvider":true,"hoverProvider":true,"implementationProvider":true,"inlayHintProvider":{"resolveProvider":true},"referencesProvider":{"workDoneProgress":true},"renameProvider":true,"semanticTokensProvider":{"full":false,"legend":{"tokenModifiers":["static","ReassignedVariable"],"tokenTypes":["namespace","type","class","enum","interface","struct","typeParameter","parameter","variable","property","enumMember","event","function","method","macro","keyword","modifier","comment","string","number","regexp","operator","constant","controlKeyword","delegate","excludedCode","extensionMethod","field","jsonArray","jsonComment","jsonConstructorName","jsonKeyword","jsonNumber","jsonObject","jsonOperator","jsonPropertyName","jsonPunctuation","jsonString","jsonText","label","module","operatorOverloaded","preprocessorText","punctuation","recordClass","recordStruct","regexAlternation","regexAnchor","regexCharacterClass","regexComment","regexGrouping","regexOtherEscape","regexQuantifier","regexSelfEscapedCharacter","regexText","stringEscapeCharacter","stringVerbatim","text","whitespace","xmlDocCommentAttributeName","xmlDocCommentAttributeQuotes","xmlDocCommentAttributeValue","xmlDocCommentCDataSection","xmlDocCommentComment","xmlDocCommentDelimiter","xmlDocCommentEntityReference","xmlDocCommentName","xmlDocCommentProcessingInstruction","xmlDocCommentText","xmlLiteralAttributeName","xmlLiteralAttributeQuotes","xmlLiteralAttributeValue","xmlLiteralCDataSection","xmlLiteralComment","xmlLiteralDelimiter","xmlLiteralEmbeddedExpression","xmlLiteralEntityReference","xmlLiteralName","xmlLiteralProcessingInstruction","xmlLiteralText"]},"range":true},"signatureHelpProvider":{"triggerCharacters":["(",","]},"textDocumentSync":{"change":2,"openClose":true},"workspaceSymbolProvider":true}}
2023-07-01T09:24:41.632 helix_lsp [ERROR] failed to initialize language server: failed to parse: missing field `commands`

if more information is needed, just let me know!

[the-mikedavis]

The server is missing the required commands field in the executeCommandProvider part of the ServerCapabilities. executeCommandProvider as defined as:

// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#executeCommandOptions
export interface ExecuteCommandOptions extends WorkDoneProgressOptions {
	/**
	 * The commands to be executed on the server
	 */
	commands: string[];
}

If commands were optional it would have a trailing ?. Instead the language server should send

{
  // ..
  "executeCommandProvider": {"commands": []},
  // ..
}

in its capabilities to signal that it supports executing commands but doesn't provide any commands out of the box.

[jdrst]

Yes, somewhat, but the roslyn lsp is still changing a lot. e.g. they just recently switched to named pipes. No idea if that is supported in helix, so even though i had it working a few months ago, it's probably not working today :D

On that note: i kinda gave up on it for the moment. I talked to the roslyn team and they were pretty clear that their primary concern is vscode/the devkit as lspclient. The implementation has some "extensions" to the protocol (for example solution/open to load a solution/project) and generally isn't really suited for a "generic" lsp client. They said they are open to pull requests though.
Since helix has no plugin support yet, you'd probably have to wrap the lsp or maintain a fork that adds and/or changes some things. I started on a fork like that but threw the towel quickly, because with every sync different things stopped working.

[christianfosli]

Gotcha, thanks. I'll probably just keep using vscode+devkit for C# then, and helix for other languages.

[jdrst]

this is our best bet atm: neovim/nvim-lspconfig#2657 :D

[SofusA]

I am trying to create a wrapper around the Roslyn language server to compensate for the named pipe.

I have tried to do this in this rough WIP this rough WIP. When i run my wrapper in a C# solution, it appears that LanguageServer is responding, but when i start the language server wrapper through Helix, the LanguageServer throws the attached exception.

I have tried to inspect the notifications from helix, and they do seem to include a Content-Length header.

Any help would be greatly appreciated.

Thanks!

2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "Unhandled exception: StreamJsonRpc.BadRpcHeaderException: No Content-Length header detected.\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at StreamJsonRpc.HeaderDelimitedMessageHandler.ReadCoreAsync(CancellationToken cancellationToken)\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at StreamJsonRpc.MessageHandlerBase.ReadAsync(CancellationToken cancellationToken)\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at StreamJsonRpc.JsonRpc.ReadAndHandleRequestsAsync()\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at Microsoft.CodeAnalysis.LanguageServer.LanguageServer.LanguageServerHost.WaitForExitAsync() in /build/source/src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/LanguageServer/LanguageServerHost.cs:line 59\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at Program.<<Main>$>g__RunAsync|0_0(ServerConfiguration serverConfiguration, CancellationToken cancellationToken) in /build/source/src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/Program.cs:line 135\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at Program.<<Main>$>g__RunAsync|0_0(ServerConfiguration serverConfiguration, CancellationToken cancellationToken) in /build/source/src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/Program.cs:line 143\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at System.CommandLine.CliCommand.<>c__DisplayClass32_0.<<SetAction>b__0>d.MoveNext()\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "--- End of stack trace from previous location ---\n"
2024-07-12T21:16:03.036 helix_lsp::transport [ERROR] roslyn err <- "   at System.CommandLine.Invocation.InvocationPipeline.InvokeAsync(ParseResult parseResult, CancellationToken cancellationToken)\n"

[jdrst]

I played around with a similar thing in c# but stopped at some point.
It seems like you got it working in the end. Will check that out!