This shows how to require ES modules in a node script which is itself compiled as an ES module by shadow. I made this to verify if nbb's way of requiring ES modules aligns with other tools that accomplish the same using the CLJS compiler.
Build with npx shadow-cljs compile script.
Run with node out/script.js. It will print something like:
#js {:columns 202, :rows 45}
[Function: Spinner]
| { | |
| "dependencies": { | |
| "ink-spinner": "^4.0.2", | |
| "react": "^16.14.0", | |
| "shadow-cljs": "^2.15.6", | |
| "term-size": "^3.0.0", | |
| "ws": "^8.2.1" | |
| }, | |
| "type": "module" | |
| } |
| {:source-paths ["src"] | |
| :builds | |
| {:script | |
| {:target :esm | |
| :output-dir "out" | |
| :js-options {:keep-as-import #{"term-size" "ink-spinner"}} | |
| :modules {:script {:init-fn hello.world/main}}}}} |
| ;; place this file in src/hello/world.cljs | |
| (ns hello.world | |
| (:require ["ink-spinner$default.default" :as is] ;; the double default is weird, but it's the only way that worked for me | |
| ["term-size$default" :as term-size])) | |
| (defn main [] | |
| (prn (term-size)) | |
| (.log js/console is)) |
To get this sample working, I ran:
yarn add ink
The
"ink-spinner$default.default"can be explained by the package being written in typescript but only published as commonjs.https://unpkg.com/browse/ink-spinner@4.0.2/build/index.js
In the early days of commonjs <-> esm interop webpack and others did some "smart" detection as to seemingly make interop easier. See the
__esModulemarker which was used to make commonjs look like ESM as in it allowedimport { thing } from "actually-commonjs".nodenever did such tricks and only allowsimport thing from "actually-commonjs". So only onedefaultimport which is the object exported by the package, which again only has thedefaultproperty.