Some subscribeTo methods seem to keep a node process from shutting down

[andreashuber69]

import { subscribeToBlocks } from "lightning";
import { connectLnd } from "./test/connectLnd.js";

const eventName = "block";
const waitTime = 5000;

const authenticatedLnd = await connectLnd();
const emitter = subscribeToBlocks(authenticatedLnd);
const handler = (e) => console.log(e);

emitter.on(eventName, handler);
console.log(`Waiting for ${waitTime / 1000} seconds...`);
await new Promise((resolve) => setTimeout(resolve, waitTime));
console.log("Shutting down...");
emitter.off(eventName, handler);

Playing with lightning 9.8.1, the above code works as expected. That is, I get the following output and the process ends.

Waiting for 5 seconds...
{
  height: 798407,
  id: '00000000000000000004cf4fb091ef41647bd2d2e7657e2bd82a9158b8e165b6'
}
Shutting down...

However, when I use subscribeToForwards instead of subscribeToBlocks and set eventName to forward instead of block, the process hangs after logging Shutting down.... Why?

[andreashuber69]

Sorry, I meant to open this in https://github.com/alexbosworth/lightning, but I guess it applies to this project too.

[alexbosworth]

i think this is a node.js question? if you have open listeners node.js wouldn't exit right?

[andreashuber69]

i think this is a node.js question? if you have open listeners node.js wouldn't exit right?

I would agree with you if the behavior was equivalent for subscribeToBlocks and subscribeToForwards. It clearly isn't, everything works as expected for the former but not for the latter.

Also, note that I remove the handler on the last line emitter.off(eventName, handler);

[alexbosworth]

Did you try using emitter.removeAllListeners() ?

[andreashuber69]

Did you try using emitter.removeAllListeners() ?

Just tried that, the result is the same. Works with blocks, doesn't work with forwards. Here's the CTRL-C, CTRL-V of the code:

import { subscribeToForwards } from "lightning";
import { connectLnd } from "./test/connectLnd.js";

const eventName = "forward";
const waitTime = 5000;

const authenticatedLnd = await connectLnd();
const emitter = subscribeToForwards(authenticatedLnd);
const handler = (e: unknown) => console.log(e);

emitter.on(eventName, handler);
console.log(`Waiting for ${waitTime / 1000} seconds...`);
await new Promise((resolve) => setTimeout(resolve, waitTime));
console.log("Shutting down...");
emitter.removeAllListeners();

[alexbosworth]

Hmm ok I guess it has an issue, can take a look

[alexbosworth]

Should be fixed now, can you try on the latest version?

[andreashuber69]

import { subscribeToForwards } from "lightning"; import { connectLnd } from "./test/connectLnd.js";

const eventName = "forward"; const waitTime = 5000;

const authenticatedLnd = await connectLnd(); const emitter = subscribeToForwards(authenticatedLnd); const handler = (e: unknown) => console.log(e);

emitter.on(eventName, handler); console.log(Waiting for ${waitTime / 1000} seconds...); await new Promise((resolve) => setTimeout(resolve, waitTime)); console.log("Shutting down..."); emitter.removeAllListeners();

I've tried with subscribeToForwards, subscribeToPayments, subscribeToChannels and they all now work as expected. Thank you!