website/vite.config.js

import { defineConfig } from 'vite'
import { join } from 'path'
import preactPlugin from '@preact/preset-vite'
import { getBuildRoutesMetadata } from './meta/routes.js'

/** @type {import('vite').UserConfig} */
const sharedConfig = {
    // all files processed by ViteJS are inside this folder
    root: './frontend',
    // for now the only plugin is Preact
    plugins: [preactPlugin()],
}

export default defineConfig(async config => {
    if (config.command === 'build') {
        const routes = await getBuildRoutesMetadata('out/routes.json')

        const allHtmlEntrypoints = [...Object.values(routes.static), ...Object.values(routes.dynamic)].map(file =>
            join(__dirname, 'frontend', file)
        )

        console.dir(allHtmlEntrypoints)

        return {
            ...sharedConfig,
            build: {
                outDir: '../out/frontend',
                rollupOptions: {
                    input: allHtmlEntrypoints,
                },
            },
        }
    } else {
        return {
            ...sharedConfig,
            server: {
                port: 3000,
                proxy: {
                    '/api': 'http://localhost:4000/',
                },
            },
        }
    }
})