Use Rollup for bundling dependencies

.gitignore

@@ -1,2 +1,3 @@
 node_modules
+dist
 yarn.lock

package.json

@@ -13,16 +13,19 @@
 	"type": "module",
 	"exports": {
 		"types": "./index.d.ts",
-		"default": "./source/index.js"
+		"default": "./dist/index.js"
 	},
+	"sideEffects": false,
 	"engines": {
 		"node": ">=16.10"
 	},
 	"scripts": {
+		"prepack": "npm run build",
+		"build": "rollup -c",
 		"test": "xo && ava && tsd"
 	},
 	"files": [
-		"source",
+		"dist",
 		"index.d.ts"
 	],
 	"keywords": [
@@ -59,13 +62,20 @@
 		"yargs-parser": "^21.1.1"
 	},
 	"devDependencies": {
-		"ava": "^5.2.0",
+		"@rollup/plugin-commonjs": "^25.0.3",
+		"@rollup/plugin-json": "^6.0.0",
+		"@rollup/plugin-node-resolve": "^15.1.0",
+		"@rollup/plugin-terser": "^0.4.3",
+		"ava": "^5.3.1",
 		"common-tags": "^1.8.2",
-		"execa": "^7.1.1",
+		"execa": "^7.2.0",
 		"indent-string": "^5.0.0",
 		"read-pkg": "^8.0.0",
+		"rollup": "^3.27.0",
+		"rollup-plugin-filesize": "^10.0.0",
+		"rollup-plugin-license": "^3.0.1",
 		"tsd": "^0.28.1",
-		"xo": "^0.54.2"
+		"xo": "^0.55.0"
 	},
 	"xo": {
 		"rules": {

rollup.config.js

@@ -0,0 +1,38 @@
+import json from '@rollup/plugin-json';
+import commonjs from '@rollup/plugin-commonjs';
+import {nodeResolve} from '@rollup/plugin-node-resolve';
+import license from 'rollup-plugin-license';
+import terser from '@rollup/plugin-terser';
+import filesize from 'rollup-plugin-filesize';
+import {defineConfig} from 'rollup';
+
+export default defineConfig({
+	input: 'source/index.js',
+	output: {
+		file: 'dist/index.js',
+		// https://rollupjs.org/configuration-options/#output-interop
+		interop: 'esModule',
+		// https://rollupjs.org/configuration-options/#output-generatedcode
+		generatedCode: {
+			preset: 'es2015',
+		},
+	},
+	plugins: [
+		json(),
+		commonjs(),
+		nodeResolve(),
+		license({
+			thirdParty: {
+				output: 'dist/dependencies.md',
+			},
+		}),
+		terser({
+			module: true,
+			toplevel: true,
+			format: {
+				comments: false,
+			},
+		}),
+		filesize(),
+	],
+});