Struggling to run the language server standalone

[djzager]

@razzmatazz thank you for the work you have put into this language server. I will apologize up front that my experience with C#, F#, and dotnet in general is pretty weak.

What I'm trying to do is to make specific calls to your language server independent of an editor like vscode/neovim.

What I have is a project at /opt/app-root/src that looks like:

Filetree:

├──  HelloWorld.csproj
└──  Program.cs

HelloWorld.csproj

───────┼───────────────────────────────────────────────────────────────────────────────────
   1   │ <Project Sdk="Microsoft.NET.Sdk">
   2   │
   3   │   <PropertyGroup>
   4   │     <OutputType>Exe</OutputType>
   5   │     <TargetFramework>net6.0</TargetFramework>
   6   │     <LangVersion>7.1</LangVersion>
   7   │     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   8   │     <CheckForOverflowUnderflow>true</CheckForOverflowUnderflow>
   9   │     <PlatformTarget>x64</PlatformTarget>
  10   │   </PropertyGroup>
  11   │
  12   │ </Project>
───────┴───────────────────────────────────────────────────────────────────────────────────

Program.cs

───────┼───────────────────────────────────────────────────────────────────────────────────
   1   │ using System;
   2   │
   3   │ namespace HelloWorld
   4   │ {
   5   │     class Program
   6   │     {
   7   │         static void Main(string[] args)
   8   │         {
   9   │             Console.WriteLine("Hello World!");
  10   │         }
  11   │     }
  12   │ }
───────┴───────────────────────────────────────────────────────────────────────────────────

I'm able to initialize the server just fine, but get nothing back when I make a workspace/symbol query. Here is me printing everything meaningful to demonstrate what I'm talking about.

Starting language server: '/opt/app-root/.dotnet/tools/csharp-ls' in directory '/opt/app-root/golang-lsp-cli'
Language server started
Initializing language server
Request:
{
  "jsonrpc": "2.0",
  "method": "initialize",
  "params": {
    "processId": 0,
    "rootUri": "file:///opt/app-root/src",
    "capabilities": {
      "workspace": {
        "workspaceEdit": {},
        "didChangeConfiguration": {},
        "didChangeWatchedFiles": {},
        "symbol": {},
        "executeCommand": {}
      },
      "textDocument": {
        "documentSymbol": {
          "hierarchicalDocumentSymbolSupport": true
        }
      }
    },
    "workspaceFolders": null,
    "extendedClientCapabilities": {
      "classFileContentsSupport": true
    }
  },
  "id": 1
}
Response:
{
  "capabilities": {
    "textDocumentSync": {
      "openClose": true,
      "change": 2,
      "save": {
        "includeText": true
      }
    },
    "hoverProvider": true,
    "completionProvider": {
      "triggerCharacters": [
        ".",
        "'"
      ]
    },
    "signatureHelpProvider": {
      "triggerCharacters": [
        "(",
        ",",
        "\u003c",
        "{",
        "["
      ]
    },
    "definitionProvider": true,
    "implementationProvider": true,
    "referencesProvider": true,
    "documentHighlightProvider": true,
    "documentSymbolProvider": true,
    "workspaceSymbolProvider": true,
    "codeActionProvider": {
      "resolveProvider": true
    },
    "codeLensProvider": {
      "resolveProvider": true
    },
    "documentFormattingProvider": true,
    "documentRangeFormattingProvider": true,
    "documentOnTypeFormattingProvider": {
      "firstTriggerCharacter": ";",
      "moreTriggerCharacter": [
        "}",
        ")"
      ]
    },
    "renameProvider": true,
    "callHierarchyProvider": true,
    "semanticTokensProvider": {
      "legend": {
        "tokenTypes": [
          "class",
          "comment",
          "property",
          "enumMember",
          "enum",
          "event",
          "method",
          "variable",
          "interface",
          "keyword",
          "namespace",
          "number",
          "operator",
          "parameter",
          "struct",
          "regex",
          "string",
          "typeParameter"
        ],
        "tokenModifiers": [
          "static"
        ]
      },
      "range": true,
      "full": true
    },
    "typeHierarchyProvider": true,
    "inlayHintProvider": {
      "resolveProvider": false
    }
  }
}
Language server initialized
Making call to language server
Request:
{
  "jsonrpc": "2.0",
  "method": "workspace/symbol",
  "params": {
    "query": ""
  },
  "id": 2
}
Response:
nil
Language server called

Questions:

1. When running the LSP this way, where are the logs?
2. Any idea what I could be missing as far as making a valid query?

[tcx4c70]

@djzager

1. For now, all logs are sent to client via window/showMessageRequest. You can receive the notifications then print the content.
2. It looks like that you forget to send initialized notification to csharp-ls, which tells csharp-ls that the client is ready and csharp-ls can start loading solution/project files. I don't know what lsp client you are using or you're using a lsp client written by yourself, but csharp-ls will send 2 requests, client/registerCapability and workspace/configuration, to client during loading solution/project and client should response them. For example, here is a trace from my client during initialized:

[Trace - 15:27:27.492] Sending notification 'initialized'.
Params: {}

[Trace - 15:27:27.535] Received request 'client/registerCapability - (2)'.
Params: {
    "registrations": [
        {
            "id": "id:workspace/didChangeWatchedFiles",
            "method": "workspace/didChangeWatchedFiles",
            "registerOptions": {
                "watchers": [
                    {
                        "globPattern": "**/*.{cs,csproj,sln}"
                    }
                ]
            }
        }
    ]
}

[Trace - 15:27:27.537] Sending response 'client/registerCapability - (2)'. Processing request took 2ms
No result returned.

[Trace - 15:27:27.553] Received request 'workspace/configuration - (3)'.
Params: {
    "items": [
        {
            "section": "csharp"
        }
    ]
}

[Trace - 15:27:27.555] Sending response 'workspace/configuration - (3)'. Processing request took 2ms                                                  Result: [
    null
]

[djzager]

Thank you @tcx4c70 . That helped a ton. There were a lot of changes required in the client I am working on to get it up and running. That leads me to a couple of questions:

1. According to the specificationn related to client/registerCapability, this is something that the client would "opt-in"to. Are we certain the server should be sending this request to clients that do not support dynamicRegistration?
2. Looking at the clientCapabilities, the client should be able to declare that they do not support the workspace/configuration requests. Is this something this server should respect?

[tcx4c70]

@djzager

1. csharp-ls will not send client/registerCapability if client says it doesn't support it (set workspace.didChangeWatchedFiles.dynamicRegistration to false). But if client doesn't say it, csharp-ls will think client support it, which I think we can improve it.
2. Yes, I think csharp-ls should not send the request if client declares that it doesn't support it. But for now, csharp-ls just think that all clients support it and will always send the request to client.

I'm working on rework of csharp-ls, you can try it #102 if you're interested. I think it might fix the issues you have met, but you still need to send initialized notification before you send any other requests.