element-plus/build/rollup.config.js

import vue from 'rollup-plugin-vue'
import css from 'rollup-plugin-css-only'
import { nodeResolve } from '@rollup/plugin-node-resolve'
import esbuild from 'rollup-plugin-esbuild'
import path from 'path'
import { getPackagesSync } from '@lerna/project'
import pkg from '../package.json'

const noElPrefixFile = /(utils|directives|hooks|locale)/
const getOutFile = (name, dir='lib') => {
  const compName = name.split('@element-plus/')[1]
  if(noElPrefixFile.test(name)) {
    return `${dir}/${compName}/index.js`
  }
  return `${dir}/el-${compName}/index.js`
}

const deps = Object.keys(pkg.dependencies)
const inputs = getPackagesSync()
  .map(pkg => pkg.name)
  .filter(name =>
    name.includes('@element-plus') &&
    !name.includes('transition') &&
    !name.includes('utils'),
  )

export default inputs.map(name => ({
  input: path.resolve(__dirname, `../packages/${name.split('@element-plus/')[1]}/index.ts`),
  output: [{
    format: 'es',
    file: getOutFile(name, 'es'),
    paths(id) {
      if (/^@element-plus/.test(id)) {
        if (noElPrefixFile.test(id)) return id.replace('@element-plus', '..')
        return id.replace('@element-plus/', '../el-')
      }
    },
  },{
    format: 'cjs',
    file: getOutFile(name, 'lib'),
    paths(id) {
      if (/^@element-plus/.test(id)) {
        if (noElPrefixFile.test(id)) return id.replace('@element-plus', '..')
        return id.replace('@element-plus/', '../el-')
      }
    },
  }],
  plugins: [
    css(),
    vue({
      target: 'browser',
      css: false,
    }),
    nodeResolve(),
    esbuild(),
  ],
  external(id) {
    return /^vue/.test(id)
      || /^@element-plus/.test(id)
      || deps.some(k => new RegExp('^' + k).test(id))
  },
}))