Any way to await connect() or listen for connection done / error events ?

[franklevasseur]

Is your feature request related to a problem? Please describe.

I'm trying to publish an event to a server. Here's the code (this code works):

import * as zmq from "zeromq";
import { Config } from "./config";

const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

export const runPub = async (config: Config) => {
  const publisher = new zmq.Publisher();

  publisher.connect(`tcp://127.0.0.1:${config.port}`);
  await sleep(100); // If I remove this, my code doesn't work... Any way to do this better?

  await publisher.send([
    "mychannel",
    `J${JSON.stringify({
      channel: "mychannel",
      formats: { "http-stream": { content: "a chunk of data\n" } },
    })}`,
  ]);
};

If I remove the await sleep(100) my code does not work (I do not receive the data on the subscriber side). I'd like a cleaner way of doing things.

I also tried listening on connect event but it doesnt work (I do not receive data on the subscriber side) and the program takes forever to exit.

import * as zmq from "zeromq";
import { Config } from "./config";

const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

export const runPub = async (config: Config) => {
  const publisher = new zmq.Publisher();

  // does not work
  await new Promise<void>((resolve) => {
    publisher.events.on("connect", () => {
      console.log("connected");
      resolve();
    });
    publisher.connect(`tcp://127.0.0.1:${config.port}`);
  });

  await publisher.send([
    "mychannel",
    `J${JSON.stringify({
      channel: "mychannel",
      formats: { "http-stream": { content: "a chunk of data\n" } },
    })}`,
  ]);
};

Describe the solution you'd like

Connect should return a promise if it involves async operations.

Describe alternatives you've considered

If you can listen for some sort of connection_success and connection_error events, then its allright.

Additional context

• I'm using zeromq@6.0.0-beta.17
• The subscriber side is Pushpin