rollup.config.mjs

import copy from 'rollup-plugin-copy';
import typescript from '@rollup/plugin-typescript';

export default {
	input: 'src/index.ts',
	output: {
		dir: 'dist',
		format: 'cjs',
	},
	plugins: [
		typescript(),
		copy({
			targets: [
				{
					src: 'LICENSE',
					dest: 'dist',
				},
				{
					src: 'README.md',
					dest: 'dist',
				},
				{
					src: 'package.json',
					dest: 'dist',
					transform(content) {
						const ignoredProps = ['devDependencies', 'scripts'];

						const json = JSON.parse(content.toString());
						return JSON.stringify(
							{
								...Object.fromEntries(
									Object.entries(json).filter(
										([key]) => !ignoredProps.includes(key),
									),
								),
								main: 'index.js',
							},
							null,
							4,
						);
					},
				},
			],
		}),
	],
};