Add support for import()

fixtures/fetch.mjs

@@ -0,0 +1,6 @@
+import fetch from 'node-fetch';
+
+export default async function (port) {
+  const res = await fetch('http://localhost:' + port + '/');
+  return res.text();
+}

fixtures/jump.js

@@ -0,0 +1,4 @@
+module.exports = async function (port) {
+  const fetch = await import('./fetch.mjs');
+  return fetch.default(port);
+};

src/binding.cc

@@ -258,8 +258,7 @@ void Worker::Start(bool own_loop, bool own_microtaskqueue) {
       {},
       {},
       static_cast<EnvironmentFlags::Flags>(
-          EnvironmentFlags::kTrackUnmanagedFds |
-          EnvironmentFlags::kNoRegisterESMLoader),
+          EnvironmentFlags::kTrackUnmanagedFds),
       thread_id,
       std::move(inspector_parent_handle));
   assert(env_ != nullptr);

test/index.ts

@@ -1,4 +1,5 @@
 import assert from 'assert';
+import { join } from 'path';
 import SynchronousWorker from '../';
 
 describe('SynchronousWorker allows running Node.js code', () => {
@@ -208,4 +209,20 @@ describe('SynchronousWorker allows running Node.js code', () => {
     });
     await w.stop();
   });
+
+  it('support import', async() => {
+    const w = new SynchronousWorker({ sharedEventLoop: true, sharedMicrotaskQueue: true });
+    const req = w.createRequire(__filename);
+    const httpServer = req('http').createServer((_, res) => {
+      res.writeHead(200);
+      res.end('Ok\n');
+    });
+    await new Promise((resolve) => {
+      httpServer.listen(0, resolve);
+    });
+    const fetch = req(join(__dirname, '..', 'fixtures', 'jump.js'));
+    const res = await fetch(httpServer.address().port);
+    assert.strictEqual(res, 'Ok\n');
+    httpServer.close();
+  });
 });