A minimal WAMP 1.0 protocol implementation to be used with the new League of Legends client (LCU)

index.js

process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";

const WebSocket = require('ws');

const MESSAGE_TYPES = {
    WELCOME: 0,
    PREFIX: 1,
    CALL: 2,
    CALLRESULT: 3,
    CALLERROR: 4,
    SUBSCRIBE: 5,
    UNSUBSCRIBE: 6,
    PUBLISH: 7,
    EVENT: 8
};

class RiotWSProtocol extends WebSocket {

    constructor(url) {
        super(url, 'wamp');

        this.session = null;
        this.on('message', this._onMessage.bind(this));
    }

    close() {
        super.close();
        this.session = null;
    }

    terminate() {
        super.terminate();
        this.session = null;
    }

    subscribe(topic, callback) {
        super.addListener(topic, callback);
        this.send(MESSAGE_TYPES.SUBSCRIBE, topic);
    }

    unsubscribe(topic, callback) {
        super.removeListener(topic, callback);
        this.send(MESSAGE_TYPES.UNSUBSCRIBE, topic);
    }

    send(type, message) {
        super.send(JSON.stringify([type, message]));
    }

    _onMessage(message) {
        const [type, ...data] = JSON.parse(message);

        switch (type) {
            case MESSAGE_TYPES.WELCOME:
                this.session = data[0];
                // this.protocolVersion = data[1];
                // this.details = data[2];
                break;
            case MESSAGE_TYPES.CALLRESULT:
                console.log('Unknown call, if you see this file an issue at https://discord.gg/hPtrMcx with the following data:', data);
                break;
            case MESSAGE_TYPES.TYPE_ID_CALLERROR:
                console.log('Unknown call error, if you see this file an issue at https://discord.gg/hPtrMcx with the following data:', data);
                break;
            case MESSAGE_TYPES.EVENT:
                const [topic, payload] = data;
                this.emit(topic, payload);
                break;
            default:
                console.log('Unknown type, if you see this file an issue with at https://discord.gg/hPtrMcx with the following data:', [type, data]);
                break;
        }
    }
}

/** HOW TO USE */
const ws = new RiotWSProtocol('wss://riot:Vb4qOZdKanoA-9UB9gAN_Q@localhost:60588/');

ws.on('open', () => {
    ws.subscribe('OnJsonApiEvent', console.log);
});

package.json

{
  "name": "lcu-ws-protocol",
  "version": "0.0.1",
  "main": "index.js",
  "author": "Robert Manolea <[email protected]>",
  "license": "MIT",
  "dependencies": {
    "ws": "^4.0.0"
  }
}

I tried to send: [2, "GetLolSummonerV1CurrentSummoner"]

I got back: [4,"GetLolSummonerV1CurrentSummoner","InvalidRequest","Invalid WAMP call procedure URI.",0]

According to the WAMP documentation, I need some sort of resource identifier but I can not find what the LCU accepts. I have successfully retrieved the list of functions and subscribable events. How do I invoke functions through WAMP? What sort of prefix do they need?

You were missing the request ID. Either add an empty string, or add one randomly generated by you. E.g. [2, "123", "GetLolSummonerV1CurrentSummoner"].