1 files changed, 34 insertions, 13 deletions

diff --git a/lib/internal/vm/source_text_module.js b/lib/internal/vm/source_text_module.js
index c1c3611d8f..d22db6e914 100644
--- a/lib/internal/vm/source_text_module.js
+++ b/lib/internal/vm/source_text_module.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const { isModuleNamespaceObject } = require('util').types;
 const { URL } = require('internal/url');
 const { isContext } = internalBinding('contextify');
 const {
@@ -9,7 +10,7 @@ const {
   ERR_VM_MODULE_LINKING_ERRORED,
   ERR_VM_MODULE_NOT_LINKED,
   ERR_VM_MODULE_NOT_MODULE,
-  ERR_VM_MODULE_STATUS
+  ERR_VM_MODULE_STATUS,
 } = require('internal/errors').codes;
 const {
   getConstructorOf,
@@ -21,6 +22,7 @@ const { validateInt32, validateUint32 } = require('internal/validators');
 
 const {
   ModuleWrap,
+  callbackMap,
   kUninstantiated,
   kInstantiating,
   kInstantiated,
@@ -43,8 +45,6 @@ const perContextModuleId = new WeakMap();
 const wrapMap = new WeakMap();
 const dependencyCacheMap = new WeakMap();
 const linkingStatusMap = new WeakMap();
-// vm.SourceTextModule -> function
-const initImportMetaMap = new WeakMap();
 // ModuleWrap -> vm.SourceTextModule
 const wrapToModuleMap = new WeakMap();
 const defaultModuleName = 'vm:module';
@@ -63,7 +63,8 @@ class SourceTextModule {
       context,
       lineOffset = 0,
       columnOffset = 0,
-      initializeImportMeta
+      initializeImportMeta,
+      importModuleDynamically,
     } = options;
 
     if (context !== undefined) {
@@ -96,13 +97,16 @@ class SourceTextModule {
     validateInt32(lineOffset, 'options.lineOffset');
     validateInt32(columnOffset, 'options.columnOffset');
 
-    if (initializeImportMeta !== undefined) {
-      if (typeof initializeImportMeta === 'function') {
-        initImportMetaMap.set(this, initializeImportMeta);
-      } else {
-        throw new ERR_INVALID_ARG_TYPE(
-          'options.initializeImportMeta', 'function', initializeImportMeta);
-      }
+    if (initializeImportMeta !== undefined &&
+        typeof initializeImportMeta !== 'function') {
+      throw new ERR_INVALID_ARG_TYPE(
+        'options.initializeImportMeta', 'function', initializeImportMeta);
+    }
+
+    if (importModuleDynamically !== undefined &&
+        typeof importModuleDynamically !== 'function') {
+      throw new ERR_INVALID_ARG_TYPE(
+        'options.importModuleDynamically', 'function', importModuleDynamically);
     }
 
     const wrap = new ModuleWrap(src, url, context, lineOffset, columnOffset);
@@ -110,6 +114,22 @@ class SourceTextModule {
     linkingStatusMap.set(this, 'unlinked');
     wrapToModuleMap.set(wrap, this);
 
+    callbackMap.set(wrap, {
+      initializeImportMeta,
+      importModuleDynamically: importModuleDynamically ? async (...args) => {
+        const m = await importModuleDynamically(...args);
+        if (isModuleNamespaceObject(m)) {
+          return m;
+        }
+        if (!m || !wrapMap.has(m))
+          throw new ERR_VM_MODULE_NOT_MODULE();
+        const childLinkingStatus = linkingStatusMap.get(m);
+        if (childLinkingStatus === 'errored')
+          throw m.error;
+        return m.namespace;
+      } : undefined,
+    });
+
     Object.defineProperties(this, {
       url: { value: url, enumerable: true },
       context: { value: context, enumerable: true },
@@ -245,6 +265,7 @@ class SourceTextModule {
 
 module.exports = {
   SourceTextModule,
-  initImportMetaMap,
-  wrapToModuleMap
+  wrapToModuleMap,
+  wrapMap,
+  linkingStatusMap,
 };