nodemjs

Run .mjs files from your command line, with all the tweaks from esmod-pmb.

Added features:

• Legacy-resolves module names passed with -r if they would otherwise yield the ERR_MODULE_RESOLUTION_LEGACY error.
• Pre-imports all modules listed in env var NODEMJS_PRELOAD and npm setting nodemjs-preload (see caveats below). Multiple module specs can be separated with spaces. They will be loaded even before the -r pre-imports.

API

No.

CLI

$ nodemjs test/uc1st.mjs
{ scriptFile: '/mnt/…/nodemjs/test/uc1st.mjs' }
uc1st: [ 'Using dummy input', 'Because there were', 'No CLI args' ]

$ ./test/uc1st.mjs foo bar qux
{ scriptFile: '/mnt/…/nodemjs/test/uc1st.mjs' }
uc1st: [ 'Foo', 'Bar', 'Qux' ]

$ ./test/dynamicMap.mjs rot-13 '' foo bar qux ; echo rv=$?
dynamicMap: import failed for: rot-13
(node:11549) UnhandledPromiseRejectionWarning: Error: Cannot find module 'rot-13'
    at […]
(node:11549) [DEP0018] DeprecationWarning: Unhandled promise rejections are
    deprecated. In the future, promise rejections […] terminate […] Node.js […]
rv=0

# Fortunately, you can just pre-import the future with -r:
$ nodemjs -r p-fatal test/dynamicMap.mjs rot-13 '' foo bar qux ; echo rv=$?
dynamicMap: import failed for: rot-13
Error: Cannot find module 'rot-13'
    at […]
rv=1

# … or via the env var:
$ export NODEMJS_PRELOAD='p-fatal'
$ ./test/dynamicMap.mjs rot-13 '' foo bar qux ; echo rv=$?
dynamicMap: import failed for: rot-13
Error: Cannot find module 'rot-13'
    at […]
rv=1

# and once you've installed it…
$ ./test/dynamicMap.mjs rot-13 '' foo bar qux
[ 'sbb', 'one', 'dhk' ]

Setup

1. npm install --global nodemjs
2. Make sure you have a node.js (compatible) binary available as the nodejs command. If you use sane package sources, you probably do. If you don't, just make a symlink nodejs to node or whatever it's called on your system. (If you'd like to argue the supremacy of the more generic node command name, file an issue, ideally after you've renamed the Node.js foundation to Node foundation.) As of 0.1.7, you can configure your favorite nodejs replacement via the NODEJS_CMD env var.

Known issues

• Currently no support for setting process.mainModule, see the upstream bug ticket.

• npm config caveat: The nodemjs-preload npm setting is currently ignored if its value as a string is literally undefined. If you want to pre-load a module with that name and nothing else, put it in twice, with a space between. See also: Duplicate pre-imports.

• Duplicate pre-imports: nodemjs currently does not check whether a module you're trying to pre-import had already been imported before. Usually node's module cache voids all non-first import attempts per module, so this won't matter — unless you use cache-busting modules, in which case you're on your own.

• REPL: The REPL isn't upgraded to ESM because esm currently cannot expose its REPL in a clean and easy way.

• The invokedAs context property for nodemjsCliMain doesn't work.

• Needs more/better tests and docs.

License

ISC