Loader is run twice if requireModule is called from CJS dependency

[thecopy]

Hello,

My loader file is executed twice and it seems it is caused by a CJS dependency which calls createRequire. Importing createRequire in my ESM script does not execute loader script twice.

Is this expected?

Repro: loader.mjs

console.log('loaded')

index.mjs

import { pino } from 'pino';
const logger = pino({ transport: { target: 'pino-pretty' }});
logger.info("hello")

Execute:

$ npm i pino pino-pretty
$ node --import=./loader.mjs index.mjs
loaded
loaded
[10:59:13.501] INFO (23004): hello

If i remove { transport: { target: 'pino-pretty' }}:

node --import=./loader.mjs index.mjs
loaded
{"level":30,"time":1728896437188,"pid":23035,"hostname":"Eriks-MacBook-Pro.local","msg":"hello"}

Node v20.18.0 Pino createRequire call: https://github.com/pinojs/pino/blob/main/lib/transport.js#L150

[jsumners-nr]

You are starting a worker thread by way of the Pino transport. Each thread will execute the loader.