Settings for Microsoft Python Language Server

[hanspinckaers]

Hi,

I'm trying to get Microsoft Python Language Server working. Sadly, I can't get it to work. I'm seeing this error when enabling the highest logging level:

10:08:18 INFO reader-python src/vim.rs:380 <= Some("python") {
  "jsonrpc": "2.0",
  "id": 9,
  "error": {
    "code": -32000,
    "message": "Object reference not set to an instance of an object.",
    "data": {
      "stack": "   at Microsoft.Python.LanguageServer.Implementation.LanguageServer.Initialize(JToken token, CancellationToken cancellationToken) in /mnt/data/python-language-server/src/LanguageServer/Impl/LanguageServer.Lifetime.cs:line 41",
      "code": "-2147467261"
    }
  }
}

I think this is related to certain initializationOptions that need to be set. They should be like these:
https://github.com/Microsoft/python-language-server/blob/master/Using_in_sublime_text.md

{
    "clients":
    {
        "mspyls":
        {
            "command": [ "dotnet.exe", "exec", "C:\\python-language-server\\Microsoft.Python.LanguageServer.dll" ],
            "scopes": ["source.python"],
            "syntaxes": ["Packages/Python/Python.sublime-syntax"],
            "languageId": "python",
            "initializationOptions": 
            {
                "interpreter": 
                {
                    "properties": 
                    {
                        "UseDefaultDatabase": true,
                        "Version": "3.7"
                    }                    
                }
            }
        }
    }
}

I've tried various syntax in settings.json, but I cannot seem to get it to work. My current settings.json:

{
    "python": {
        "UseDefaultDatabase": true,
        "Version": "3.6.4"
    }
}

Thanks!

[dimbleby]

initializationOptions needs to be a top-level entry in settings.json I think.

{
    "initializationOptions": {
        "interpreter": {
      etc ...

FWIW I also had a go at the microsoft python language server a few weeks ago, and decided that it wasn't (yet?) as good as pyls anyway, as well as being much harder to get working in Vim.

[hanspinckaers]

Thanks! That did the trick. And I see completions in the log, however I get this error message afterwards:

08:43:58 ERROR main src/vim.rs:59 Error handling message: data did not match any variant of untagged enum CompletionResponse

I think because microsoft python ls returns a dictionary:

08:43:58 INFO reader-python src/vim.rs:380 <= Some("python") {
  "jsonrpc": "2.0",
  "id": 20,
  "result": {
    "isIncomplete": false,
    "items": [
      {
        "label": "next",
        "kind": 21,
        "detail": null,
        "documentation": {
          "kind": null,
          "value": "None"
        },
        "sortText": "1",
        "filterText": null,
        "preselect": null,
        "insertText": "next",
        "insertTextFormat": 0,
        "textEdit": null,
        "additionalTextEdits": null,
        "commitCharacters": null,
        "command": null,
        "data": null,
        "_kind": "constant",
        "_values": null
      },
      {
        "label": "previous",
        "kind": 21,
        "detail": null,
        "documentation": {
          "kind": null,
          "value": "None"
        },
        "sortText": "1",
        "filterText": null,
        "preselect": null,
        "insertText": "previous",
        "insertTextFormat": 0,
        "textEdit": null,
        "additionalTextEdits": null,
        "commitCharacters": null,
        "command": null,
        "data": null,
        "_kind": "constant",
        "_values": null
      }
    ],
    "_applicableSpan": null,
    "_allowSnippet": null,
    "_expr": "self",
    "_commitByDefault": true
  }
}

I however do not know enough rust to add this case to:

LanguageClient-neovim/src/languageclient.rs

Line 2130 in 283dba5

let mut matches = match result {

[dimbleby]

This one looks like a problem with the microsoft language server to me. Specifically this bit:

"documentation": {
    "kind": null,
    "value": "None"
}

which does not parse, as you can verify like this:

extern crate serde_json;
extern crate languageserver_types as lsp;
use lsp::Documentation;

fn main() {
    // let serialized = "\"just a string\"";
    // let serialized = "{\"kind\": \"plaintext\", \"value\": \"None\"}";
    let serialized = "{\"kind\": null, \"value\": \"None\"}";
    let doc: serde_json::Result<Documentation> = serde_json::from_str(&serialized);
    println!("{:?}", doc);
}

producing Err(Error("data did not match any variant of untagged enum Documentation", line: 0, column: 0)). (The commented out examples deserialize just fine).

Relevant spec is here - search for MarkupContent - and so far as I can see there's indeed no default value for the kind so I believe that the client is right to reject this and the server is wrong to send it.

(There may be other problems too, I stopped on finding this one).

@hanspinckaers: suggest you take this issue over to the language server repository, if you still care about it.

[autozimu]

@dimbleby Nice finding!

[autozimu]

This is an issue with the language server and has been acknowledged in the corresponding issue.

[johngalambos]

I went through the remainder of the exercise @dimbleby started (thanks for the nice troubleshooting method!) and I think the remaining property causing trouble (at least for me so far) is insertTextFormat values of 0. I've created another issue here: microsoft/python-language-server#342.

[Congee]

The upstream seems to have fixed the issue. Anyone tested it?

[johngalambos]

@Congee I tried it last night and Deoplete completion was working in neovim. The completion suggestion list was pretty huge though--I think there may be some other initializationOptions that need to be pushed in via settings similar to the VSCode configuration (see here: https://github.com/Microsoft/vscode-python/blob/efa175ca29476469136c07c783f6cbd28a976ff0/src/client/activation/languageServer/languageServer.ts#L280-L286) . I haven't explored this yet though. The following .settings file worked for me (I could probably clean this up a bit and make it Python specific):

{
  "enabled": true,
  "initializationOptions": {
    "displayOptions": {
      "preferredFormat": "plaintext",
      "trimDocumentationLines": true,
      "maxDocumentationLineLength": 0,
      "trimDocumentationText": true,
      "maxDocumentationTextLength": 0
    },
    "interpreter": {
      "properties": {
        "InterpreterPath": "C:/Apps/Miniconda3/envs/neovim3/python.exe",
        "UseDefaultDatabase": true,
        "Version": "3.6"
      }
    }
  }
}

[Congee]

@johngalambos Thank you for your .vim/settings.json config file 🎉🎉🎉🎉🎉🎉🎉

[shri3k]

@hanspinckaers sorry to ping you here but I'm facing an issue similar to your original one. Could you please tell me where you placed your settings.json? I have my on ~/.local/share/nvim/settings.json but apparently it's not working. I'm still getting the same error 😞.

[hanspinckaers]

Did you set let g:LanguageClient_settingsPath='~/.local/share/nvim/settings.json'? I found it outcommented in my vimrc. However I'm not sure, I'm using https://github.com/prabirshrestha/vim-lsp now which seems to handle the errors in the pyls server better.