rollup.config.js

import alias from '@rollup/plugin-alias'
import analyze from 'rollup-plugin-analyzer'
import requireContext from 'rollup-plugin-require-context'
import sass from 'rollup-plugin-sass'
import typescript from 'rollup-plugin-typescript2'
import VuePlugin from 'rollup-plugin-vue'

import fs from 'fs'
import path from 'path'

import pkg from './package.json'

let inputFilesObj = {}
function getInputFiles(dir, maxDepth, curDepth = 0) {
	if (curDepth > maxDepth) return

	fs.readdirSync(dir).forEach(file => {
		const filePath = path.join(dir, file)
		const stat = fs.statSync(filePath)

		if (stat.isDirectory()) {
			getInputFiles(filePath, maxDepth, curDepth + 1)
		} else if (file === 'index.ts') {
			inputFilesObj[path.basename(path.dirname(filePath))] = filePath
		}
	})
}

getInputFiles('src/components', 1)

const commonConfig = {
	external: [
		...Object.keys(pkg.dependencies || {}),
		...Object.keys(pkg.devDependencies || {}),
		...Object.keys(pkg.peerDependencies || {}),
		'lodash/debounce',
		'lodash/get',
		'lodash/lowerFirst',
		'lodash/pullAllBy',
		'lodash/throttle',
		'lodash/uniqBy'
	],
	plugins: [
		requireContext(),
		alias({
			resolve: ['.js', '.ts', '.vue'],
			entries: {
				'@': path.resolve(__dirname, 'src'),
				'@components': path.resolve(__dirname, 'src/components'),
				'@directives': path.resolve(__dirname, 'src/directives'),
				'@helpers': path.resolve(__dirname, 'src/helpers'),
				'@mixins': path.resolve(__dirname, 'src/mixins'),
				'@plugins': path.resolve(__dirname, 'src/plugins')
			}
		}),

		VuePlugin({
			data: { scss: '@import "./src/styles/settings/index.scss";' } // in vue.config.js this is css.loaderOptions.sass.data
		}),
		sass(),
		typescript({ tsconfig: 'tsconfig.json' })//,

		// analyze({ summaryOnly: true })
	]
}

// Every conceivable output during transition ;-)
export default [
	{
		input: 'src/components/index.js',
		output: [
			{
				file: pkg.main,
				format: 'cjs',
				sourcemap: true
			},
			{
				file: pkg.module,
				format: 'es',
				sourcemap: true
			}
		],
		...commonConfig
	},
	{
		input: {
			index: 'src/components/index.js',
			...inputFilesObj
		},
		output: [
			{
				dir: 'lib/cjs',
				format: 'cjs',
				sourcemap: true
			},
			{
				dir: 'lib/esm',
				format: 'es',
				sourcemap: true
			}
		],
		...commonConfig
	}
]