Writing some client code for a pygls server - textDocument/completion isnt a recognized method?

[blankRiot96]

Say I have a python file, D:\d\p\editor\main.py

from src.core import Core


def main():
    core = Core()
    core.run()


x = m

if __name__ == "__main__":
    main()

And at the position 9, 6 (the position after the character m) I wanted to fetch some autocompletion suggestions

Well, I read the docs regarding the features that have been implemented, this section:

But I can't really find what the request message should look like in order to use textDocument/completion?

Here's what I had for the server

from pygls.server import LanguageServer

server = LanguageServer("example-server", "v0.1")

server.start_ws("127.0.0.1", 2087)

And for the client:

import json

import websocket

LSP_WS_URL = "ws://127.0.0.1:2087"

completion_request = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "textDocument/completion",
    "params": {
        "textDocument": {"uri": "file:///D:/d/p/editor/main.py"},
        "position": {
            "line": 9,
            "character": 6,
        },
    },
}

ws = websocket.create_connection(LSP_WS_URL)
ws.send(json.dumps(completion_request))
response = ws.recv()
ws.close()

response_data = json.loads(response)
suggestions = response_data.get("result", [])

for item in suggestions:
    print(item["label"])

However, this is where i get the error

    raise JsonRpcMethodNotFound.of(feature_name)
pygls.exceptions.JsonRpcMethodNotFound: Method Not Found: textDocument/completion

Also, is there a better/easier way to write client code? I dont mind websockets but maybe yall have some suggestions

[blankRiot96]

Have I severely misunderstood what pygls does? I think so. So it doesn't provide any default completion engines for suggesting autocompletion?

[alcarney]

Ah apologies, I can see how the documentation can be a bit misleading. :/

pygls is a library/framework for writing your own language server implementation for a given language, so it doesn't offer any completion suggestions out of the box. Your screenshot above is referring to an example server implementation we have for JSON files.

If you are looking for a language server that supports Python you might be interested in jedi-language-server (which uses pygls) or pyright (written in TypeScript).

As for writing client code, pygls currently offers a BaseLanguageClient class which you can base your implementation on. It's fairly new so it's not well documented (yet!) but supports communicating with a server over stdin/stdout if you are looking for an alternative to websockets.

• Here is an example of making a textDocument/completion request.
• Here is where that test client is defined and how we start the server

Hopefully that clears up some of the confusion and I'm happy to help if you have any more questions :)

[blankRiot96]

Yeah I found jedi later on, thank you for your reply