feat: add ESM support

.github/workflows/ci.yml

@@ -20,6 +20,7 @@ jobs:
           node-version: ${{ matrix.node }}
       - run: npm install
       - run: npm test
+      - run: npm run test-esm
       - uses: coverallsapp/[email protected]
         if: matrix.node == 18
         with:

.gitignore

@@ -1,4 +1,4 @@
 node_modules/
 coverage/
-umd/
+dist/
 .tern-port

index.d.ts

@@ -131,4 +131,5 @@ declare namespace EventEmitter {
   export const EventEmitter: EventEmitterStatic;
 }
 
-export = EventEmitter;
+export { EventEmitter }
+export default EventEmitter;

index.mjs

@@ -0,0 +1,4 @@
+import EventEmitter from './index.js'
+
+export { EventEmitter }
+export default EventEmitter

package.json

@@ -2,20 +2,29 @@
   "name": "eventemitter3",
   "version": "4.0.7",
   "description": "EventEmitter3 focuses on performance while maintaining a Node.js AND browser compatible interface.",
+  "exports": {
+    ".": {
+      "import": "./index.mjs",
+      "require": "./index.js",
+      "types": "./index.d.ts"
+    },
+    "./package.json": "./package.json"
+  },
   "main": "index.js",
-  "typings": "index.d.ts",
+  "types": "index.d.ts",
   "scripts": {
-    "browserify": "rm -rf umd && mkdir umd && browserify index.js -s EventEmitter3 -o umd/eventemitter3.js",
-    "minify": "uglifyjs umd/eventemitter3.js --source-map -cm -o umd/eventemitter3.min.js",
+    "rollup": "rimraf dist umd && rollup -c",
     "benchmark": "find benchmarks/run -name '*.js' -exec benchmarks/start.sh {} \\;",
     "test": "c8 --reporter=lcov --reporter=text mocha test/test.js",
-    "prepublishOnly": "npm run browserify && npm run minify",
+    "test-esm": "mocha test/test.mjs",
+    "prepublishOnly": "npm run rollup",
     "test-browser": "node test/browser.js"
   },
   "files": [
     "index.js",
+    "index.mjs",
     "index.d.ts",
-    "umd"
+    "dist"
   ],
   "repository": {
     "type": "git",
@@ -44,13 +53,15 @@
     "url": "https://github.com/primus/eventemitter3/issues"
   },
   "devDependencies": {
+    "@rollup/plugin-commonjs": "^23.0.2",
+    "@rollup/plugin-terser": "^0.1.0",
     "assume": "^2.2.0",
-    "browserify": "^17.0.0",
     "c8": "^7.3.1",
     "mocha": "^10.0.0",
     "pre-commit": "^1.2.0",
+    "rimraf": "^3.0.2",
+    "rollup": "^3.4.0",
     "sauce-browsers": "^3.0.0",
-    "sauce-test": "^1.3.3",
-    "uglify-js": "^3.9.0"
+    "sauce-test": "^1.3.3"
   }
 }

rollup.config.mjs

@@ -0,0 +1,36 @@
+import commonjs from '@rollup/plugin-commonjs';
+import terser from '@rollup/plugin-terser';
+
+export default [{
+  input: './index.mjs',
+  output: {
+    file: 'dist/eventemitter3.esm.js',
+    format: 'es'
+  },
+  plugins: [commonjs()]
+}, {
+  input: './index.mjs',
+  output: {
+    compact: true,
+    file: 'dist/eventemitter3.esm.min.js',
+    format: 'es'
+  },
+  plugins: [commonjs(), terser()]
+}, {
+  input: './index.js',
+  output: {
+    file: 'dist/eventemitter3.umd.js',
+    format: 'umd',
+    name: 'EventEmitter3'
+  },
+  plugins: [commonjs()]
+}, {
+  input: './index.js',
+  output: {
+    compact: true,
+    file: 'dist/eventemitter3.umd.min.js',
+    format: 'umd',
+    name: 'EventEmitter3'
+  },
+  plugins: [commonjs(), terser()]
+}];

test/test.mjs

@@ -0,0 +1,9 @@
+import EventEmitterDefault, { EventEmitter } from '../index.mjs';
+
+it('exports `EventEmitter` as default export', () => {
+  new EventEmitterDefault();
+})
+
+it('exports `EventEmitter` as a named export', () => {
+  new EventEmitter();
+})