export-like-require-context.mjs

import path from 'path'
import { promises as fs } from 'fs'
import { camelCase } from 'lodash-es'

const [ , self, dir, mergeFlag] = process.argv

if (!dir) {
  console.log(`
    usage: 
    node ${path.relative(process.cwd(), self)} <target-dir> [--merge]
  `)
  process.exit(1)
}

const isMerge = mergeFlag === '--merge'

const list = await fs.readdir(dir)

const fileNames = list
  .filter(item => (
    item !== 'index.ts'
    && /\.ts$/.test(item)
  ))
  .map(file => file.replace(/\.ts$/, ''))

console.log(`
// generated by
// node ${path.relative(process.cwd(), self)} ${dir} ${isMerge ? '--merge' : ''}

${
  fileNames
    .map(fileName => `import { default as ${camelCase(fileName)} } from './${fileName}'`)
    .join('\n')
}


export default {
  ${
    fileNames
      .map(fileName => camelCase(fileName))
      .map(fileName => isMerge
        ? `...${fileName},`
        : `${fileName},`
      )
      .join('\n  ')
  }
}
`)