use .mjs for node esm module

jest.esm.mjs

@@ -12,8 +12,9 @@
 
 //Jest doc: https://jestjs.io/docs/ecmascript-modules
 
-const bundleName = process.env.BUNDLE_ENV === 'browser' ? 'esm.browser.mjs' : 'esm.node.mjs';
-const OktaAuth = `<rootDir>/build/bundles-for-validation/esm/${bundleName}`;
+const OktaAuth = process.env.BUNDLE_ENV === 'browser' ? 
+  `<rootDir>/build/bundles-for-validation/esm/esm.browser.mjs` : 
+  `<rootDir>/build/esm/esm.node.mjs`;
 const testEnvironment = process.env.BUNDLE_ENV === 'browser' ? 'jsdom' : 'node';
 
 export default {

package.json

@@ -6,12 +6,12 @@
   "homepage": "https://github.com/okta/okta-auth-js",
   "license": "Apache-2.0",
   "main": "build/cjs/index.js",
-  "module": "build/esm/esm.node.js",
+  "module": "build/esm/esm.node.mjs",
   "browser": "build/dist/okta-auth-js.umd.js",
   "types": "build/lib/index.d.ts",
   "exports": {
     "node": {
-      "import": "./build/esm/esm.node.js",
+      "import": "./build/esm/esm.node.mjs",
       "require": "./build/cjs/index.js"
     },
     "browser": {

rollup.config.js

@@ -106,19 +106,10 @@ export default [
     output: [
       {
         format: 'esm',
-        file: 'build/esm/esm.node.js',
+        file: 'build/esm/esm.node.mjs',
         exports: 'named',
         sourcemap: true
-      },
-      // not emit test bundle for development
-      (process.env.NODE_ENV !== 'development' && {
-        // generate ems bundle for jest test, ".mjs" extension should be used
-        // this bundle is excluded from the release package
-        format: 'esm',
-        file: 'build/bundles-for-validation/esm/esm.node.mjs',
-        exports: 'named',
-        sourcemap: true
-      })
+      }
     ]
   }
 ];

test/apps/node-esm/index.js

@@ -0,0 +1,7 @@
+/* eslint-disable */
+import { OktaAuth } from "@okta/okta-auth-js";
+
+const oktaAuth = new OktaAuth({ 
+  issuer: 'https://xxx.okta.com',
+  clientId: '0oal89rzfrHjIVqQw5d6'
+});

test/apps/node-esm/package.json

@@ -0,0 +1,12 @@
+{
+  "private": true,
+  "name": "@okta/test.app.node-esm",
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "start": "node index.js"
+  },
+  "dependencies": {
+    "@okta/okta-auth-js": "*"
+  }
+}