How can an ES6 module be run as a script in Node?

Question

How can an ES6 module be run as a script in Node?

When I try this shebang I get an error:

#!/usr/bin/env node --experimental-modules

/usr/bin/env: ‘node --experimental-modules’: No such file or directory

If I use this shebang it has syntax errors (of course):

#!/usr/bin/env node

SyntaxError: Unexpected token import

The work around I'm using is to use a shell script to call the module:

#!/usr/bin/env sh

BASEDIR=$( dirname "$0" )
node --experimental-modules $BASEDIR/script.mjs "$@"

Is it possible to get this working without a second file?

Answer 1

I've patched Ishan Thilina Somasiri solution to work with Node 13 without the .mjs extension:

#!/usr/bin/env bash
":" //# comment; exec /usr/bin/env node --input-type=module - "$@" < "$0"

import { hostname } from 'os';

console.log(hostname());

The trick is pretty much the same, but using stdin, which is the only documented way when you don't have a package.json nor the .mjs extension. Thus, a standalone extensionless script.

However, global variables like __dirname or __filename won't be available.