Adding a --loader makes extensionless files fail to run

[giltayar]

To reproduce:

1. Generate a runnable extensionless file (let's call it runcjs):

#!/usr/bin/env node

console.log('hello')

(note that the hashbang has nothing to do with it and can be removed. I just found it out because I was trying to run a file in ./node_modules/.bin and those are usually extensionless)

2. Run it with node:

node ./runcjs

This works!

3. Now add a loader (empty mjs file):

node --loader=./empty.mjs ./runcjs

This fails with the exception [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension "" for ../runcjs

This was tested with Node v14.2.0.

[ljharb]

I believe this is also nodejs/node#33226 ?

[giltayar]

Yup, sorry. Duplicate. I'll close this. Thanks!

[DerekNonGeneric]

You may be able to do this for now.

node --experimental-specifier-resolution=node --experimental-loader=./empty.mjs ./runcjs

You'll need to do something with that getFormat loader hook though.

// empty.mjs
export async function getFormat(url, context, defaultGetFormat) {
  return {
    format: 'commonjs',
  }
}

This workaround may also be a clue to what's currently bugged too.