pre-compile.mts

// This script is work for build-server
// Pre generate common chunk for output

import path from 'path'
import fsp from 'fs/promises'

import { readAll } from './src/server/shared'

const defaultWd = process.cwd()

const clientPath = path.join(defaultWd, 'dist', 'client')
const clientAssetsPath = path.join(clientPath, 'assets')

export interface Descriptor {
  kind: 'script' | 'style' | 'title'
  text: string
  attrs?: string[]
}

interface InjectHTMLTagOptions {
  html: string
  injectTo: 'body' | 'head'
  descriptors: Descriptor | Descriptor[]
}

// Refactor this function
function injectHTMLTag(options: InjectHTMLTagOptions) {
  const regExp = options.injectTo === 'head' ? /([ \t]*)<\/head>/i : /([ \t]*)<\/body>/i
  options.descriptors = Array.isArray(options.descriptors) ? options.descriptors : [options.descriptors]
  const descriptors = options.descriptors.map(d => {
    if (d.attrs && d.attrs.length > 0) {
      return `<${d.kind} ${d.attrs.join(' ')}>${d.text}</${d.kind}>`
    }
    return `<${d.kind}>${d.text}</${d.kind}>`
  })
  return options.html.replace(regExp, (match) => `${descriptors.join('\n')}${match}`)
}

async function main() {
  const clientAssetsPaths = await readAll(clientAssetsPath)
  const clientAssets = await Promise.all(clientAssetsPaths.map(async (p) => {
    const fileType = path.extname(p).replace('.', '')
    const content = await fsp.readFile(p, 'utf8')
    return { fileType, content }
  }))
  const assets = clientAssets.filter(a => ['js', 'css'].includes(a.fileType))
  let html = await fsp.readFile(path.join(clientPath, 'index.html'), 'utf8')
  html = injectHTMLTag({
    html,
    injectTo: 'head',
    descriptors: [
      { text: '<--title-->', kind: 'title' },
      ...assets.map(({ fileType, content }) => ({
        kind: fileType === 'js' ? 'script' : 'style',
        text: content,
        attrs: fileType === 'js' ? ['type="module"'] : []
      })) satisfies Descriptor[]
    ]
  })
  html = injectHTMLTag({
    html,
    injectTo: 'body',
    descriptors: {
      kind: 'script',
      text: '<--module-->'
    } satisfies Descriptor | Descriptor[]
  })

  process.stdout.write(`export function html (title, module) {
    return ${JSON.stringify(html)}.replace('<--title-->', title).replace('<--module-->', module)
    }`)
}

main()