rollup.config.dev.js

import { babel } from '@rollup/plugin-babel';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import clear from 'rollup-plugin-clear';
import progress from 'rollup-plugin-progress';
import cleanup from 'rollup-plugin-cleanup';
import typescript from 'rollup-plugin-typescript2';

const extensions = ['.js', '.ts'];

const baseConfig = {
	input: './lib/index.ts',
	output: [
		{
			dir: 'build/esm',
			format: 'esm',
		},
	],
	plugins: [
		clear({
			// required, point out which directories should be clear.
			targets: ['build'],
			// optional, whether clear the directores when rollup recompile on --watch mode.
			watch: true, // default: false
		}),
		resolve({ extensions }),
		commonjs(),
		cleanup({
			comments: 'jsdoc',
			compactComments: false,
		}),
		typescript(),
		babel({
			extensions,
			babelHelpers: 'bundled',
			babelrc: false,
			// sourceMap: 'inline',
			retainLines: true,
			presets: [
				[
					'@babel/preset-env',
					{
						targets: {
							browsers: 'last 2 versions',
							node: 'current',
						},
					},
				],
			],
			plugins: ['@babel/plugin-proposal-class-properties'],
		}),
		progress(),
	],
};

export default baseConfig;