MaxListenersExceededWarning: Possible EventEmitter memory leak detected

[mitchdowney]

I am trying to use beta.12. It seems like event listeners are not getting cleared after

Basically after I call this function 11 times:

const sendMessage = async (dm: any, text: string) => {
  try {
    const message = await dm.sendMessage(text);
    console.log('reply:', message.content);
  } catch (error) {
    console.log('sendMessage error:', error);
  }
};

I get this error:

node:18476) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 rawMessage listeners added to [CAIWebsocket]. Use emitter.setMaxListeners() to increase limit

Any ideas what could be going wrong? Am I using the dm object improperly? Do I need to create a new dm object before every usage of sendMessage?

[realcoloride]

Hey there while this is the intended way to do this, the warning and potential leak is not normal. I will check this out soon.

[mitchdowney]

Update on this issue. I'm working from the dist code so this probably looks different from source.

I see the original code like this:

const disconnectHandlerAndResolve = () => {
    var _a;
    console.log(`${logPrefix} disconnectHandlerAndResolve called. Removing listener.`);
    (_a = this.websocket) === null || _a === void 0 ? void 0 : _a.removeListener("rawMessage", handler);
    console.log(`${logPrefix} Listener removed. Remaining listeners:`, this.listenerCount("rawMessage"));
    resolve(options.streaming ? streamedMessage === null || streamedMessage === void 0 ? void 0 : streamedMessage.concat(message) : message);
};

With that code, I see in my logs that the remove listener logic is called, and the code doesn't error, but the count of the listeners is unchanged / continues to grow with each message sent.

but when i change it to this:

const disconnectHandlerAndResolve = () => {
    console.log(`${logPrefix} disconnectHandlerAndResolve called. Removing listener.`);
    // Log all current listeners for rawMessage
    const listenersBefore = this.listeners("rawMessage");
    console.log(`${logPrefix} Listeners before removal:`, listenersBefore);
    console.log(`${logPrefix} Handler reference:`, handler);

    // Remove the handler
    this.off("rawMessage", handler);

    // Log all listeners after removal
    const listenersAfter = this.listeners("rawMessage");
    console.log(`${logPrefix} Listeners after removal:`, listenersAfter);
    console.log(`${logPrefix} Listener removed. Remaining listeners:`, this.listenerCount("rawMessage"));

    resolve(options.streaming ? (streamedMessage?.concat(message)) : message);
};

The modified version removes the handler from the EventEmitter instance that is emitting "rawMessage" events, whereas the original version removes the listener from the underlying websocket (which Copilot tells me "probably never emits rawMessage so it does nothing in your context).

Anyway, I didn't have much time to investigate so apologies for this LLM driven info. I'm sharing this because the second version does seem to correctly display the remaining listeners as 0, but I'm not sure what the implications of removing the EventEmitter instead of the websocket listener may result in and if this is a viable fix.

[realcoloride]

Hey there no worries

I had a really long week! (I'm moving, and still am) I'll solve this problem by the end of the week.

Thank you for your patience!

[realcoloride]

Hello there, I'm going to investigate and fix the problem now.

[Skidy89]

Hello there, I'm going to investigate and fix the problem now.

hi,
i think i fixed it with this code!

async sendAsync(options: ICAIWebsocketMessage): Promise<string | any> {
        return new Promise(resolve => {
            let streamedMessage: any[] | undefined = options.streaming ? [] : undefined;
            let turn: any;
            const handler = async (message: string | any) => {
                if (options.parseJSON) message = await Parser.parseJSON(message, false);
                const { request_id: requestId, command } = message;
                const { expectedReturnCommand } = options;

                // check for requestId (if specified)
                if (requestId && requestId != options.expectedRequestId) return;

                let isFinal = undefined;
                try {
                    // get turn
                    switch (options.messageType) {
                        case CAIWebsocketConnectionType.DM: turn = message.turn; break;
                        case CAIWebsocketConnectionType.GroupChat: turn = message.push?.data?.turn; break;
                    }
                    
                    if (turn)
                        isFinal = turn.candidates[0].is_final;
                } finally {
                    // if turn is NOT present, push to queue
                    streamedMessage?.push(message);

                    const condition = options.waitForAIResponse ? !turn?.author?.is_human && isFinal : isFinal;
                    
                    // if expectedReturnCommand or condition is met
                    if ((expectedReturnCommand && command == expectedReturnCommand) || condition) {
                        this.off("rawMessage", handler);
                        resolve(options.streaming ? streamedMessage?.concat(message) : message);
                    }
                }
            }
            this.on("rawMessage", handler);
            this.websocket?.send(options.data);
        });
    }

[realcoloride]

Hello there, commit b1bd043 was done to fix the following issue. I will do QA and push to a new version once done.

If you wish to test on your end to test it out, feel free to do so.