From f2e0a2a6ff36189976c5db73bb9428c3dbb976e5 Mon Sep 17 00:00:00 2001
From: Timur Shemsedinov <timur.shemsedinov@gmail.com>
Date: Tue, 24 Oct 2023 22:27:43 +0300
Subject: [PATCH] Add stub for ESM

PR-URL: https://github.com/metarhia/metavm/pull/117
---
 metavm.js    |  4 ++++
 test/unit.js | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/metavm.js b/metavm.js
index 45c990b..5ccbc12 100644
--- a/metavm.js
+++ b/metavm.js
@@ -19,6 +19,7 @@ const CONTEXT_OPTIONS = {
 const MODULE_TYPE = {
   METARHIA: 1,
   COMMONJS: 2,
+  ECMA: 3,
 };
 
 const DEFAULT = {
@@ -87,6 +88,9 @@ const internalRequire = require;
 
 class MetaScript {
   constructor(name, src, options = {}) {
+    if (options.type === MODULE_TYPE.ECMA) {
+      throw new Error('ECMAScript modules is not supported');
+    }
     this.name = name;
     this.dirname = options.dirname || process.cwd();
     this.relative = options.relative || '.';
diff --git a/test/unit.js b/test/unit.js
index ab2da8b..22055e5 100644
--- a/test/unit.js
+++ b/test/unit.js
@@ -455,3 +455,21 @@ test('Check native fetch', async () => {
   assert.ok(proto);
   assert.strictEqual(proto.constructor.name, 'AsyncFunction');
 });
+
+test('ECMAScript modules', async () => {
+  const sandbox = {};
+  sandbox.global = sandbox;
+  const src = `const fn = x => x;
+export { fn };
+`;
+  try {
+    const ms = metavm.createScript('Example', src, {
+      context: metavm.createContext(sandbox),
+      dirname: __dirname,
+      type: metavm.MODULE_TYPE.ECMA,
+    });
+    test.fail(ms);
+  } catch (err) {
+    assert.ok(err);
+  }
+});