LSP: textDocument/completion hangs starting in version 1.43

[aaronhuggins]

Version: Deno 1.43, 1.44, 1.45, 1.46

Prior to version 1.43, the following code worked as expected and provided a completion response. Starting at 1.43, the response for a textDocument/completion just hangs, holding up the parent process.

This code snippet is for reproduction purposes.

import * as rpc from "npm:[email protected]/node.js";
import { Readable, Writable } from "node:stream";

const uri = "file:///stub.ts";
const text = "console.";
const languageId = "typescript";
const command = new Deno.Command(Deno.execPath(), {
    args: ["lsp"],
    stderr: "null",
    stdin: "piped",
    stdout: "piped",
});
const process = command.spawn();
const connection = rpc.createMessageConnection(
    new rpc.StreamMessageReader(Readable.fromWeb(process.stdout as any)),
    new rpc.StreamMessageWriter(Writable.fromWeb(process.stdin)),
);

connection.listen();

const res = await connection.sendRequest("initialize", {
    processId: Deno.pid,
    capabilities: {},
    rootUri: null,
    clientInfo: {
        name: "example",
        version: "0.10.11",
    },
    locale: "en",
    initializationOptions: {
        enable: true,
    },
});

console.log(res);

await connection.sendNotification("textDocument/didOpen", {
    textDocument: {
        uri,
        text,
        version: 1,
        languageId,
    },
});

const res2 = await connection.sendRequest("textDocument/completion", {
    textDocument: { uri },
    position: { line: 1, character: 8 },
    context: { triggerKind: 1 },
});

console.log(res2);

connection.end();
process.kill();

[nayeemrmn]

You have to send the initialized notification after receiving the response to initialize. This unblocks the rest of the language server. We do this because the proper pull-based configuration (though it's not really applicable to your client) cannot be fetched until the initialized handler and we want to make sure it's incorporated before processing other requests. See microsoft/language-server-protocol#567 (comment).

Working as intended.

[aaronhuggins]

Thanks, Nayeem! This appears to be a gap in the protocol docs, as the language for the client sending initialized notification is “may” and not “must”. I’ll follow up there for clarification.

…

On Fri, Sep 13, 2024 at 9:47 PM Nayeem Rahman ***@***.***> wrote: Closed #25610 <#25610> as not planned. — Reply to this email directly, view it on GitHub <#25610 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AD6MWR3TKEUOSL47OFAI4L3ZWOPUXAVCNFSM6AAAAABOEOSAPCVHI2DSMVQWIX3LMV45UABCJFZXG5LFIV3GK3TUJZXXI2LGNFRWC5DJN5XDWMJUGI2TMNBXGU3DGMA> . You are receiving this because you authored the thread.Message ID: ***@***.***>