rollup.config.js

import { dirname, join } from 'node:path'
import { nodeExternals } from 'rollup-plugin-node-externals'
import fs, { mkdir } from 'node:fs/promises'
import copy from 'rollup-plugin-copy'

/**
 * @return {import("rollup").RollupOptions[]}
 */
function main() {
  const common = {
    treeshake: true,
    plugins: [
      nodeExternals(),
      inlinePlugin(),
      createPackages(),
      copy({
        targets: [
          {
            src: './src/*.d.ts',
            dest: ['./dist/cjs/', './dist/esm/'],
          },
        ],
      }),
    ],
  }
  return [
    {
      ...common,
      input: {
        index: './src/index.js',
        ast: './src/ast.js',
      },
      output: {
        entryFileNames: '[name].mjs',
        dir: './dist/esm',
        format: 'esm',
      },
    },
    {
      ...common,
      input: {
        index: './src/index.js',
        ast: './src/ast.js',
      },
      output: {
        dir: './dist/cjs',
        format: 'cjs',
      },
    },
  ]
}

function inlinePlugin() {
  return {
    name: 'inline-plugin',
    async transform(code, path) {
      if (/(__inline_(\w+)[ ]?\=)/g.test(code)) {
        // DO NOT REMOVE THESE, as they are used by `eval`
        // to execute the inline path action
        const { readFileSync } = await import('node:fs')
        const __dirname = dirname(path)
        const { join } = await import('node:path')

        return code.replace(
          /(__inline_(\w+)\s?\=\s?(.+)[;]?[\n]?)/g,
          (...matchers) => {
            return `__inline_${matchers[2]} = \`${escapeJS(
              eval(matchers[3])
            )}\``
          }
        )
      }
    },
  }
}

export default main

function escapeJS(code) {
  return escapeTemplateLiterals(escapeBackticks(code))
}

function escapeBackticks(code) {
  return code.replace(/`/g, '\\`')
}

function escapeTemplateLiterals(code) {
  return code.replace(/\$\{/g, '\\${')
}

/**
 *
 * @returns {import("rollup").Plugin}
 */
function createPackages() {
  let meta
  return {
    name: 'create-final-packages',
    async renderStart(info) {
      const pkg = {}
      if (info.format == 'cjs') {
        pkg.type = 'commonjs'
      }
      await mkdir(info.dir, { recursive: true })
      if (['esm', 'es'].includes(info.format)) {
        pkg.type = 'module'
      }
      await fs.writeFile(
        join(info.dir, 'package.json'),
        JSON.stringify(pkg, null, 2),
        'utf-8'
      )
    },
  }
}