Babel-node does not transpile files references by workers. Can/should it?

I find that using new Worker(file.js) (and file.js uses import statements), that babel loads the referenced script fine but babel-node doesn’t. Is this a bug or related to how babel-node works (my understanding of these things is not so good)?

I have just posted a StackOverflow question with more detail: https://stackoverflow.com/questions/59662352/how-to-get-babel-node-to-convert-files-referenced-by-workers-to-commonjs-like

[JLHwung]

babel-cli transforms all the JavaScript files inside the src folder. It operates on per-file level and does not process the module references.

How does Node allow 3rd party code to be executed per module extension?

Under the hood babel-node uses pirates, which overwrites Module._extension[".js"]. So when a module is loaded, the babel transform defined here will be executed: https://github.com/babel/babel/blob/a0a9c64a470acec77bec1da0b4bceec4ccf7f446/packages/babel-register/src/node.js#L62

[JLHwung]

The Worker constructor does not invoke Module constructor so babel-node could not hook into the loader and apply the transformation. You can use @babel/register to hook into any files loaded inside your worker:

file-wrapper.js

require("@babel/register")
require("file.js") // your worker entry

main.js

new Worker("file-wrapper.js")