support esm

babel.config.json

@@ -0,0 +1,3 @@
+{
+  "presets": ["@parcel/babel-preset"]
+}

package.json

@@ -3,13 +3,15 @@
   "version": "1.0.0",
   "private": true,
   "license": "CC0-1.0",
+  "type": "module",
   "scripts": {
     "test": "jest",
     "start": "parcel index.html --open",
     "build": "parcel build index.html"
   },
   "devDependencies": {
-    "jest": "^27.0.6",
-    "parcel": "^2.0.0-beta.3.1"
+    "@parcel/babel-preset": "^2.0.0-alpha.2",
+    "jest": "^27.5.1",
+    "parcel": "^2.3.1"
   }
 }

renovate.json

@@ -0,0 +1,4 @@
+{
+  "extends": ["config:base", "config:semverAllMonthly"],
+  "automerge": true
+}

src/sum.js

@@ -1,6 +1,5 @@
-/** @license https://github.com/facebook/jest/blob/master/LICENSE */
-
 function sum(a, b) {
   return a + b;
 }
-module.exports = sum;
+
+export default sum;

src/sum.test.js

@@ -1,7 +1,5 @@
-/** @license https://github.com/facebook/jest/blob/master/LICENSE */
+import sum from "./sum";
 
-const sum = require("./sum");
-
-test("adds 1 + 2 to equal 3", () => {
+test("1 と 2 の合計は 3", () => {
   expect(sum(1, 2)).toBe(3);
 });