feat: migrate build system to Rolldown and improve TypeScript configuration

- Replace Rollup + ESBuild with Rolldown for faster, simpler builds
- Remove redundant type declarations, leverage TypeScript inference
- Modernize TypeScript config (ES2020 target, bundler resolution)
- Simplify build scripts and configuration files
- Add ES module support with "type": "module"
- Reduce build dependencies from 7 packages to just Rolldown

Build performance: ~90ms with Rolldown (native TypeScript support)
All 70 tests passing successfully

Author: meabed

jest.config.js renamed to jest.config.cjs

@@ -40,15 +40,14 @@
   "main": "lib/index.js",
   "module": "lib/index.es.js",
   "types": "lib/index.d.ts",
+  "type": "module",
   "files": [
     "lib",
     "resources"
   ],
   "scripts": {
-    "build": "yarn build:main && yarn build:serverless",
-    "build:main": "rm -rf lib && rollup -c rollup.config.cjs && yarn build:types",
-    "build:serverless": "rollup -c rollup.config.serverless.cjs",
-    "build:types": "tsc --declaration --emitDeclarationOnly --outDir lib --declarationMap",
+    "build": "rm -rf lib && rolldown -c && yarn build:types",
+    "build:types": "tsc --emitDeclarationOnly",
     "check": "biome check .",
     "format": "biome format --write .",
     "lint": "biome lint .",
@@ -58,9 +57,8 @@
     "prepublishOnly": "yarn build",
     "release": "semantic-release",
     "release:dry": "semantic-release --dry-run",
-    "test": "jest",
-    "watch": "rm -rf lib && rollup -cw rollup.config.cjs",
-    "watch:serverless": "rollup -cw rollup.config.serverless.cjs"
+    "test": "NODE_OPTIONS='--experimental-vm-modules' jest",
+    "watch": "rm -rf lib && rolldown -c --watch"
   },
   "config": {
     "commitizen": {
@@ -83,21 +81,15 @@
   },
   "devDependencies": {
     "@biomejs/biome": "^2.2.2",
-    "@rollup/plugin-commonjs": "^28.0.6",
-    "@rollup/plugin-json": "^6.1.0",
-    "@rollup/plugin-node-resolve": "^16.0.1",
-    "@rollup/plugin-terser": "^0.4.4",
     "@types/bson": "^4.2.4",
     "@types/jest": "^30.0.0",
     "@types/node": "^24.3.0",
     "@types/shelljs": "^0.8.17",
-    "esbuild": "^0.25.9",
     "husky": "^9.1.7",
     "jest": "^30.1.3",
     "lint-staged": "^16.1.6",
     "prettier": "^3.6.2",
-    "rollup": "^4.50.0",
-    "rollup-plugin-esbuild": "^6.2.1",
+    "rolldown": "^1.0.0-beta.34",
     "shelljs": "^0.10.0",
     "ts-jest": "^29.4.1",
     "tslib": "^2.8.1",

package.json

@@ -0,0 +1,77 @@
+import { readFileSync } from 'node:fs'
+import { defineConfig } from 'rolldown'
+
+const pkg = JSON.parse(readFileSync('./package.json', 'utf-8'))
+
+// External dependencies - don't bundle these
+const external = [
+  ...Object.keys(pkg.dependencies || {}),
+  ...Object.keys(pkg.peerDependencies || {}),
+]
+
+// Main library build (with external dependencies)
+export default defineConfig([
+  // Main build - CommonJS and ESM
+  {
+    input: 'src/index.ts',
+    output: [
+      {
+        file: 'lib/index.js',
+        format: 'cjs',
+      },
+      {
+        file: 'lib/index.es.js',
+        format: 'es',
+      },
+    ],
+    external,
+    resolve: {
+      extensions: ['.ts', '.js', '.json'],
+    },
+  },
+  // Serverless build - Bundle everything
+  {
+    input: 'src/index.serverless.ts',
+    output: [
+      {
+        file: 'lib/serverless.cjs.js',
+        format: 'cjs',
+        exports: 'named',
+      },
+      {
+        file: 'lib/serverless.esm.js',
+        format: 'es',
+      },
+      {
+        file: 'lib/serverless.umd.js',
+        format: 'umd',
+        name: 'PhoneNumberValidator',
+        exports: 'named',
+      },
+    ],
+    resolve: {
+      extensions: ['.ts', '.js', '.json'],
+    },
+  },
+  // Serverless minified builds
+  {
+    input: 'src/index.serverless.ts',
+    output: [
+      {
+        file: 'lib/serverless.esm.min.js',
+        format: 'es',
+        minify: true,
+      },
+      {
+        file: 'lib/serverless.umd.min.js',
+        format: 'umd',
+        name: 'PhoneNumberValidator',
+        exports: 'named',
+        minify: true,
+      },
+    ],
+    resolve: {
+      extensions: ['.ts', '.js', '.json'],
+    },
+  },
+])

rolldown.config.js

@@ -6,7 +6,7 @@ import { type LRU, lru } from 'tiny-lru'
 import type { CarrierLocale, GeocoderLocale } from './locales'
 
 const DEFAULT_CACHE_SIZE = 100
-let codeDataCache: LRU<Document> = lru<Document>(DEFAULT_CACHE_SIZE)
+let codeDataCache = lru<Document>(DEFAULT_CACHE_SIZE)
 
 // Resource loader interface - platforms must implement this
 export interface ResourceLoader {
@@ -21,7 +21,7 @@ export function setResourceLoader(loader: ResourceLoader) {
   resourceLoader = loader
 }
 
-async function getCodeAsync(dataPath: string, nationalNumber: string): Promise<string | null> {
+async function getCodeAsync(dataPath: string, nationalNumber: string) {
   if (!dataPath || !nationalNumber || !resourceLoader) {
     return null
   }
@@ -52,7 +52,7 @@ async function getCodeAsync(dataPath: string, nationalNumber: string): Promise<s
   return null
 }
 
-function getCodeSync(dataPath: string, nationalNumber: string): string | null {
+function getCodeSync(dataPath: string, nationalNumber: string) {
   if (!dataPath || !nationalNumber || !resourceLoader || !resourceLoader.loadResourceSync) {
     return null
   }
@@ -87,8 +87,8 @@ async function getLocalizedDataAsync(
   resourceType: 'geocodes' | 'carrier',
   phonenumber: PhoneNumber | undefined,
   locale: string,
-  fallbackLocale: string = 'en'
-): Promise<string | null> {
+  fallbackLocale = 'en'
+) {
   if (!phonenumber) {
     return null
   }
@@ -119,8 +119,8 @@ function getLocalizedDataSync(
   resourceType: 'geocodes' | 'carrier',
   phonenumber: PhoneNumber | undefined,
   locale: string,
-  fallbackLocale: string = 'en'
-): string | null {
+  fallbackLocale = 'en'
+) {
   if (!phonenumber) {
     return null
   }
@@ -151,20 +151,18 @@ function getLocalizedDataSync(
 export async function geocoderAsync(
   phonenumber: PhoneNumber | undefined,
   locale: GeocoderLocale = 'en'
-): Promise<string | null> {
+) {
   return getLocalizedDataAsync('geocodes', phonenumber, locale, 'en')
 }
 
 export async function carrierAsync(
   phonenumber: PhoneNumber | undefined,
   locale: CarrierLocale = 'en'
-): Promise<string | null> {
+) {
   return getLocalizedDataAsync('carrier', phonenumber, locale, 'en')
 }
 
-export async function timezonesAsync(
-  phonenumber: PhoneNumber | undefined
-): Promise<string[] | null> {
+export async function timezonesAsync(phonenumber: PhoneNumber | undefined) {
   if (!phonenumber || !phonenumber.number) {
     return null
   }
@@ -186,21 +184,15 @@ export async function timezonesAsync(
 }
 
 // Sync versions (requires sync resource loader)
-export function geocoder(
-  phonenumber: PhoneNumber | undefined,
-  locale: GeocoderLocale = 'en'
-): string | null {
+export function geocoder(phonenumber: PhoneNumber | undefined, locale: GeocoderLocale = 'en') {
   return getLocalizedDataSync('geocodes', phonenumber, locale, 'en')
 }
 
-export function carrier(
-  phonenumber: PhoneNumber | undefined,
-  locale: CarrierLocale = 'en'
-): string | null {
+export function carrier(phonenumber: PhoneNumber | undefined, locale: CarrierLocale = 'en') {
   return getLocalizedDataSync('carrier', phonenumber, locale, 'en')
 }
 
-export function timezones(phonenumber: PhoneNumber | undefined): string[] | null {
+export function timezones(phonenumber: PhoneNumber | undefined) {
   if (!phonenumber || !phonenumber.number) {
     return null
   }
@@ -221,15 +213,15 @@ export function timezones(phonenumber: PhoneNumber | undefined): string[] | null
   return null
 }
 
-export function clearCache(): void {
+export function clearCache() {
   codeDataCache.clear()
 }
 
-export function getCacheSize(): number {
+export function getCacheSize() {
   return codeDataCache.size
 }
 
-export function setCacheSize(size: number): void {
+export function setCacheSize(size: number) {
   const oldCache = codeDataCache
   codeDataCache = lru<Document>(size)