Function call never yields result

[berwyn]

I have an Elgato WaveLink microphone, and the user-space software for that exposes a JSON-RPC interface to control the microphone. Using the following code, I can connect and attempt to issue a command against the software. The handler I directly register on the socket will log the message coming back just fine, but the awaited call never resolves. Any idea what could be causing this?

❯ deno --version
deno 1.8.1 (release, x86_64-pc-windows-msvc)
v8 9.0.257.3
typescript 4.2.2

import { createRemote } from './deps.ts';

console.log('Opening connection...');

const socket = new WebSocket('ws://127.0.0.1:1824');
socket.addEventListener('open', () => console.log('connection open'));
socket.addEventListener('message', message => console.debug(message)); // This will successfully log out the response
socket.addEventListener('error', error => console.error(error));
socket.addEventListener('close', () => console.log('connection closed'));

const remote = await createRemote(socket);
const appInfo = await remote.getApplicationInfo(); // This never resolves

console.log('Got app info:')
console.debug(appInfo);

[timonson]

The handlers you registered directly are - under working conditions - unnecessary but I am sure you already knew this. You are using the right syntax and it should actually work. Did you try the ws example already? I only tested gentle_rpc on Linux yet but it should work on Windows, too. Please let me know if the examples don't work on your machine neither (with the exception of the BadResource error which will be fixed in the next deno version).

Otherwise, is there another way to replicate this behavior without the microphone?

Thanks!

EDIT:

Does the server respond with a valid RPC response object with an id? You should be able to check this with your message handler. It is important that the response has an id in this case, please check this.

[berwyn]

Oh, good call on the response, I just checked the payload that returns and it seems to have id: 0 instead of the one that went on the request! The payload looks otherwise well-formed, so it seems like Elgato isn't correctly matching the id of the request with the response. Well, guess that's something to file with them. Thanks for the help!

That said, I did attempt to run the examples and they do not seem to work on Windows (at least on my machine) but that's something I can look into and PR separately :)