Bundle NPM Package so it has different import paths with Vite and Typescript - node.js

Question

How can I bundle my NPM package in a way that I can have different import paths for different parts of the package? I have found webpack approaches, but I am using Vite and TS.
My package looks like this:
- src
- atoms
- molecules
- organism
- index.ts (currently simply imports and exports everything)
Now I can use this currently like this
import { Button } from '#mypackage/library'
How can I do it, so I get this outcome:
import { Button } from '#mypackage/library/atom'
Here is the relevant part of my package.json
{
"entry": "src/index.ts",
"main": "dist/index.cjs.js",
"module": "dist/index.es.js",
"types": "dist/index.d.ts",
"files": [
"dist",
"src"
],
"exports": {
".": {
"import": "./dist/index.es.js",
"require": "./dist/index.cjs.js",
"types": "./dist/index.d.ts"
},
"./package.json": "./package.json",
"./atoms": "./src/atoms/index.ts",
"./molecules": "./src/molecules/index.ts",
"./organisms": "./src/organisms/index.ts",
"./theme": "./src/theme/index.ts"
},
}
Here is my vite.config.ts
export default defineConfig({
build: {
lib: {
entry: path.resolve(__dirname, 'src/index.ts'),
formats: ['es', 'cjs'],
name: '#workdigtital/component-library-react',
fileName: (format) => `index.${format}.js`
},
rollupOptions: {
external: ['react', 'react-dom'],
output: {
globals: {
react: 'React',
'react-dom': 'ReactDOM'
},
exports: 'named'
}
}
},
plugins: [react(), dts({ insertTypesEntry: true })],
resolve: {
alias: {
'#': path.resolve(__dirname, './src')
}
}
});
If I currently try an import like this, inside another project (Laravel+React), in which installed the library.
import { ThemeProvider } from '#workdigital/component-library-react/theme';
I get the following run time error (But no Typescript errors, even IntelliSense is working):
Failed to load url /resources/js/theme/ThemeProvider (resolved id: /resources/js/theme/ThemeProvider). Does the file exist?
My resulting Dist folder looks like this:

Answer 1

You can't have TypeScript exports, this simply won't work. An npm package should have only JS exports.
If you want to be able to selectively import different parts of your package, you must transpile them to different files.
rollup can do it, but it is lots of work, as you will have to set up a separate target for each exported file. Normally you use rollup to create a single bundle, this what this tool is made for.
tsc with a tsconfig.json will be a much better choice in your case. It does this by default, you only need to specify the output directory and it will produce a separate file for each source.
There is an excellent guide on the TypeScript site about packaging TypeScript libraries, you should probably start there.