@mikkel-ol/tunnelmole/src/tunnelmole.ts

Tunnelmole, an open source ngrok alternative. Instant public URLs for any http/https based application. Available as a command line application or as an NPM dependency for your code. Stable and maintained. Good test coverage. Works behind firewalls

import { initialiseClientId } from "./identity/client-id-service.js";
import { Options } from "./options.js";
import { initStorage } from "./node-persist/storage.js";
import { eventHandler, URL_ASSIGNED } from "./events/event-handler.js";
import { setUpAutoReconnect } from "./websocket/setup-auto-reconnect.js";
import { connect } from "./websocket/connect.js";
import { setIsCli } from "./websocket/connection-info-service.js";
import detectPort from "detect-port";
import chalk from "chalk";

export default async function tunnelmole(
  options: Options,
  isCli = false
): Promise<string> {
  await initStorage();
  await initialiseClientId();
  setIsCli(isCli);

  const { port } = options;

  // Set port to 3000 if port is not specified
  if (port === undefined) {
    options.port = 3000;
  }

  if (options.setApiKey) {
    return "We are simply setting the API key here. No need to set up a tunnel";
  }

  const availablePort = await detectPort(options.port);
  if (availablePort == options.port && !isCli) {
    console.warn(
      `
${chalk.yellow.bold(`You currently don't have anything running on port ${port}`)}. Please start your service on port ${chalk.bold(port)} so that requests can reach your service. You may have also chosen the wrong port, in which case, find out what port your service is actually running on.
`
    );
  }

  const websocket = await connect(options);

  // Set up auto reconnect
  setUpAutoReconnect(options, websocket);

  // Return the URL as soon as its assigned
  return new Promise((resolve) => {
    eventHandler.on(URL_ASSIGNED, (url: string) => {
      resolve(url);
    });
  });
}