website/vite.config.js

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

import crypto from 'crypto'

/** @type {import('vite').UserConfig} */
const sharedConfig = {
    root: './frontend',
    plugins: [preactPlugin()],
}

function routesToRollupInput([route, file]) {
    const chunkName =
        file
            .replaceAll('.html', '')
            .replaceAll('index', '')
            .replace(/^\/|\/$/, '')
            .replaceAll('/', '-') +
        '-' +
        crypto.createHash('md5').update(route).update(file).digest('hex').slice(0, 8)

    return [chunkName, join(__dirname, 'frontend', file)]
}

export default defineConfig(async config => {
    if (config.command === 'build') {
        const routes = await getBuildRoutesMetadata('out/routes.json')
        const input = Object.fromEntries(
            [...Object.entries(routes.static), ...Object.entries(routes.dynamic).map(([route, { htmlFile }]) => [route, htmlFile])].map(
                routesToRollupInput
            )
        )

        console.dir(input)

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