vm: add modules

Adds vm.Module, which wraps around ModuleWrap to provide an interface
for developers to work with modules in a more reflective manner.

Co-authored-by: Timothy Gu <timothygu99@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/17560
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>

test/parallel/test-vm-module-basic.js

@@ -0,0 +1,54 @@
+'use strict';
+
+// Flags: --experimental-vm-modules
+
+const common = require('../common');
+const assert = require('assert');
+const { Module, createContext } = require('vm');
+
+common.crashOnUnhandledRejection();
+
+(async function test1() {
+  const context = createContext({
+    foo: 'bar',
+    baz: undefined,
+    typeofProcess: undefined,
+  });
+  const m = new Module(
+    'baz = foo; typeofProcess = typeof process; typeof Object;',
+    { context }
+  );
+  assert.strictEqual(m.status, 'uninstantiated');
+  await m.link(common.mustNotCall());
+  m.instantiate();
+  assert.strictEqual(m.status, 'instantiated');
+  const result = await m.evaluate();
+  assert.strictEqual(m.status, 'evaluated');
+  assert.strictEqual(Object.getPrototypeOf(result), null);
+  assert.deepStrictEqual(context, {
+    foo: 'bar',
+    baz: 'bar',
+    typeofProcess: 'undefined'
+  });
+  assert.strictEqual(result.result, 'function');
+}());
+
+(async () => {
+  const m = new Module(
+    'global.vmResult = "foo"; Object.prototype.toString.call(process);'
+  );
+  await m.link(common.mustNotCall());
+  m.instantiate();
+  const { result } = await m.evaluate();
+  assert.strictEqual(global.vmResult, 'foo');
+  assert.strictEqual(result, '[object process]');
+  delete global.vmResult;
+})();
+
+(async () => {
+  const m = new Module('while (true) {}');
+  await m.link(common.mustNotCall());
+  m.instantiate();
+  await m.evaluate({ timeout: 500 })
+    .then(() => assert(false), () => {});
+})();