Node.js Core Module Support

Clear and concise description of the problem

This might seem like a very weird use case for Vite, but I’ve been experimenting with developing a framework to develop normal Node.js libraries or even CLIs using Vite as the core. Hugely inspired by how Vitest works with vite-node, it aims to centralise all the previous build tools (tsc, rollup, testing etc.) into one convenient package using the same Vite config. Plain, simple and easy to setup a modern ESM-first TS project with far less dependencies to go around. So far, the watch mode uses the normal esbuild transforms, rollup for production etc. Essentially a modern TSDX replacement, I’ve been pleasantly surprised that Vite makes a good fit even if it isn’t the original intended use case.

Which leads to one slight hiccup. Vite does not really support any libraries that call Node.js core modules since the intended target is browsers only.

For example, trying to develop a CLI using cac returns the following error when running vite build:

1: import { EventEmitter } from 'events';
            ^
error during build:
Error: 'EventEmitter' is not exported by __vite-browser-external, imported by ../../node_modules/cac/dist/index.mjs

A workaround is to update rollupOptions.external to include the "events" library (and also "node:events"). This isn’t ideal considering there are many core Node.js modules, thus it’d be better to resolve this upstream.

Suggested solution

My proposal is to add an additional option in the Vite config that allows the resolver to ignore any imports that call the Node.js built-in modules. It could probably be a boolean value with the key node?

I feel an option like that could also let a different type of ecosystem to thrive and we may see more interesting Node-based projects using Vite, especially due to vite-node.

Alternative

https://github.com/vitejs/vite/issues/2694#issuecomment-826195660 is the most similar issue I’ve found, although the solution is not optimal in the above-given context as the libraries are not intended for the browser.

Additional context

No response

Validations

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[bluwy]

A workaround is to update rollupOptions.external to include the "events" library (and also "node:events"). This isn’t ideal considering there are many core Node.js modules, thus it’d be better to resolve this upstream.

What about using import { builtinModules } from 'module' and pass the list of nodejs builtin modules to rolllupOptions.external? I’m not sure it’s good to officially support this usecase yet since it’s a niche one. And it may be better done externally first too to quickly make changes. Until it’s stablized (e.g. vite-node), there may be a chance Vite could officially support it.

[abarke]

I could imagine that if target: "node12" is set that esbuild takes over the build instead of rollup in this case.