(ab?)using Node module hooks to speed up development

https://immaculata.dev/blog/hacking-nodejs-modules.html

by sbjs • 1 year ago

38 16 1 year ago

immaculata.dev

feisuzhu• 1 year ago

(ab)?using ?

kaeruct• 1 year ago

Using. But also maybe abusing.

carlosneves• 1 year ago

I think he's proposing a fix for the regex in the title.

/(ab?)using/ matches:

- ausing

- abusing

while /(ab)?using/ matches:

- using

- abusing

skinkestek• 1 year ago

Am I missing something, or is the content here too minimal?

For this to be genuinely useful, I’d expect at least a few code examples—and ideally a link to a working repo to show it in action.

sbjs6• 1 year ago

Just added some code samples, thanks for the suggestion.

noob_07• 1 year ago

I do not follow, can anyone help with more code/config examples of how to leverage this?

shakna• 1 year ago

One example from the site:

    import module from 'node:module'
    const tree = new FileTree('site', import.meta.url)
    module.registerHooks(hooks.useTree(tree))
    import('site/myfile.js')

Here, site/myfile.js doesn't exist. It gets created as a reference by the FileTree library. Node thinks it is importing it. The import is also automatically reloaded, if the backend changes it. Caches are invalidated and objects replaced.

sbjs6• 1 year ago

Oh no, I must have mis-explained it.

The file `site/myfile.js` does exist. All FileTree does is recursively load all files in a dir into memory.

The `useTree` module hook does two things:

* Pulls the file from memory when loading it instead of from disk

* Adds a cache busting query string when resolving it for invalidation

Combined with tree.watch(), this essentially allows you to add a very lightweight but extremely accurate hot module replacement system into Node.js

    const tree = new FileTree('src', import.meta.url)
    registerHooks(useTree(tree))
    tree.watch().on('filesUpdated', () => import(tree.root + '/myfile.js'))
    import(tree.root + '/myfile.js')

Now save src/myfile.js and see it re-executed

devrandoom• 1 year ago

It's hard to get the idea down from one's head into a document, as this text shows.

sbjs6• 1 year ago

Just updated the text to be hopefully much clearer.

whizzter• 1 year ago

With Typescript you could(prob still can) specify how JSX tags are translated, so you can get the regular data structure without React dependency.

sbjs6• 1 year ago

That's orthogonal, and in fact you probably would use TypeScript to translate JSX to JS when using this library. What this does is (a) provide a Node.js module hook to call your transpile function when it encounters TSX/JSX files, and (b) provide a Node.js module that lets you remap imports, including "react/jsx-runtime" if you want a different JSX implementation.

vermilingua• 1 year ago

This is a reinvention of HMR, no?

sbjs6• 1 year ago

It's a highly optimized and extremely simple yet robust implementation of it, sure. Is that reason to dismiss it?

Consider Vite's node-side HMR implementation. It creates its own module system on top of Node's native module system, using `node:vm`. So its modules are really second class citizens that have to be glued to the native module system.

This library used to do that, but moved to using Node's native module hooks, so that there's nothing magical going on, and you can still use the `import` expression to import your HMR modules, they just auto-update when saving.

ricardobeat• 1 year ago

This is in essence being used to emulate Bun.js behaviour with node. Have you tried bun?

(ab?)using Node module hooks to speed up development

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