Cannot import mdns from a Worker

[bguezzie]

I am trying to use mdns from inside of a Node.js Worker, but when I do I get the following error:
Module did not self-register: '/<...snipped...>/node_modules/mdns/build/Release/dns_sd_bindings.node'.

The import statement (written in TypeScript) is:
import mdns, {Browser, Service} from "mdns";

When I do this from the main thread, it works like a charm. I have done all the usual npm/node_modules tricks online trying to resolve and/or rebuild the library, but no dice.

OS: MacOS 12.5.1
Node: 18.9.0
mdns: 2.7.2

Please let me know what other information would be helpful here.

[bguezzie]

For what it's worth, I have isolated the error as arising from the import statement itself (a simple console log statement afterward never gets executed).

[bguezzie]

Here's the associated stack trace (sorry I forgot it earlier):

    at Object.Module._extensions..node (node:internal/modules/cjs/loader:1203:18)
    at Module.load (node:internal/modules/cjs/loader:997:32)
    at Function.Module._load (node:internal/modules/cjs/loader:838:12)
    at Module.require (node:internal/modules/cjs/loader:1021:19)
    at require (node:internal/modules/cjs/helpers:103:18)
    at Object.<anonymous> (/<...snipped...>/node_modules/mdns/lib/dns_sd.js:24:20)
    at Module._compile (node:internal/modules/cjs/loader:1119:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1173:10)
    at Object.require.extensions.<computed> [as .js] (/<...snipped...>/node_modules/ts-node/src/index.ts:1608:43)
    at Module.load (node:internal/modules/cjs/loader:997:32)

[bguezzie]

In case it helps, here's what the TS compiles to:

var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const node_worker_threads_1 = require("node:worker_threads");
console.log('WONK: About to import...');  // <-- this is output
const mdns_1 = __importDefault(require("mdns"));
console.log(`WONK: ${mdns_1.default.tcp('foo')}`);  // <-- never gets here

[bguezzie]

Another interesting data point: Our project had been importing the module in the main thread (creating an Advertisement) as well as in the worker thread. When I comment out the import from the main thread and stub out the calls, the import works in the worker thread (tested a few times now without any error...I see both the log message before and after the import).

[agnat]

Hi @bguezzie,
thanks for reporting this. Could you do me a favour and provide a pure javascript minimal reproducer? Just a single file (or block of code) that launches a worker and fails on require(...) demonstrating the issue.

Thanks!