nodejs · devsnek · Jul 30, 2020 · Jul 30, 2020
diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
@@ -32,6 +32,7 @@ const {
   ArrayPrototypeJoin,
   Error,
   JSONParse,
+  Map,
   Number,
   ObjectCreate,
   ObjectDefineProperty,
@@ -112,6 +113,8 @@ const {
 } = require('internal/util/types');
 
 const asyncESM = require('internal/process/esm_loader');
+const ModuleJob = require('internal/modules/esm/module_job');
+const { ModuleWrap, kInstantiated } = internalBinding('module_wrap');
 const {
   encodedSepRegEx,
   packageInternalResolve
@@ -371,7 +374,7 @@ function tryPackage(requestPath, exts, isMain, originalPath) {
 // In order to minimize unnecessary lstat() calls,
 // this cache is a list of known-real paths.
 // Set to an empty Map to reset.
-const realpathCache = new SafeMap();
+const realpathCache = new Map();
 
 // Check if the file exists and is not a directory
 // if using --preserve-symlinks and isMain is false,
@@ -1115,6 +1118,31 @@ Module.prototype.load = function(filename) {
   }
   Module._extensions[extension](this, filename);
   this.loaded = true;
+
+  const ESMLoader = asyncESM.ESMLoader;
+  const url = `${pathToFileURL(filename)}`;
+  const module = ESMLoader.moduleMap.get(url);
+  // Create module entry at load time to snapshot exports correctly
+  const exports = this.exports;
+  // Called from cjs translator
+  if (module !== undefined && module.module !== undefined) {
+    if (module.module.getStatus() >= kInstantiated)
+      module.module.setExport('default', exports);
+  } else {
+    // Preemptively cache
+    // We use a function to defer promise creation for async hooks.
+    ESMLoader.moduleMap.set(
+      url,
+      // Module job creation will start promises.
+      // We make it a function to lazily trigger those promises
+      // for async hooks compatibility.
+      () => new ModuleJob(ESMLoader, url, () =>
+        new ModuleWrap(url, undefined, ['default'], function() {
+          this.setExport('default', exports);
+        })
+      , false /* isMain */, false /* inspectBrk */)
+    );
+  }
 };
 
 
@@ -1234,7 +1262,7 @@ Module.prototype._compile = function(content, filename) {
   const exports = this.exports;
   const thisValue = exports;
   const module = this;
-  if (requireDepth === 0) statCache = new SafeMap();
+  if (requireDepth === 0) statCache = new Map();
   if (inspectorWrapper) {
     result = inspectorWrapper(compiledWrapper, thisValue, exports,
                               require, module, filename, dirname);

diff --git a/lib/internal/modules/esm/loader.js b/lib/internal/modules/esm/loader.js
@@ -5,7 +5,8 @@ require('internal/modules/cjs/loader');
 
 const {
   FunctionPrototypeBind,
-  ObjectSetPrototypeOf
+  ObjectSetPrototypeOf,
+  SafeMap,
 } = primordials;
 
 const {
@@ -45,6 +46,9 @@ class Loader {
     // Registry of loaded modules, akin to `require.cache`
     this.moduleMap = new ModuleMap();
 
+    // Map of already-loaded CJS modules to use
+    this.cjsCache = new SafeMap();
+
     // This hook is called before the first root module is imported. It's a
     // function that returns a piece of code that runs as a sloppy-mode script.
     // The script may evaluate to a function that can be called with a

diff --git a/lib/internal/modules/esm/translators.js b/lib/internal/modules/esm/translators.js
@@ -11,8 +11,6 @@ const {
   StringPrototypeReplace,
 } = primordials;
 
-const assert = require('internal/assert');
-
 let _TYPES = null;
 function lazyTypes() {
   if (_TYPES !== null) return _TYPES;
@@ -134,21 +132,27 @@ const isWindows = process.platform === 'win32';
 const winSepRegEx = /\//g;
 translators.set('commonjs', function commonjsStrategy(url, isMain) {
   debug(`Translating CJSModule ${url}`);
-  let filename = internalURLModule.fileURLToPath(new URL(url));
-  if (isWindows)
-    filename = StringPrototypeReplace(filename, winSepRegEx, '\\');
+  const pathname = internalURLModule.fileURLToPath(new URL(url));
+  const cached = this.cjsCache.get(url);
+  if (cached) {
+    this.cjsCache.delete(url);
+    return cached;
+  }
+  const module = CJSModule._cache[
+    isWindows ? StringPrototypeReplace(pathname, winSepRegEx, '\\') : pathname
+  ];
+  if (module && module.loaded) {
+    const exports = module.exports;
+    return new ModuleWrap(url, undefined, ['default'], function() {
+      this.setExport('default', exports);
+    });
+  }
   return new ModuleWrap(url, undefined, ['default'], function() {
     debug(`Loading CJSModule ${url}`);
-    let module = CJSModule._cache[filename];
-    if (!module || !module.loaded) {
-      module = new CJSModule(filename);
-      module.filename = filename;
-      module.paths = CJSModule._nodeModulePaths(module.path);
-      CJSModule._cache[filename] = module;
-      module.load(filename);
-      assert(module && module.loaded);
-    }
-    this.setExport('default', module.exports);
+    // We don't care about the return val of _load here because Module#load
+    // will handle it for us by checking the loader registry and filling the
+    // exports like above
+    CJSModule._load(pathname, undefined, isMain);
   });
 });
 

diff --git a/test/es-module/test-esm-snapshot.mjs b/test/es-module/test-esm-snapshot.mjs
@@ -3,4 +3,4 @@ import '../fixtures/es-modules/esm-snapshot-mutator.js';
 import one from '../fixtures/es-modules/esm-snapshot.js';
 import assert from 'assert';
 
-assert.strictEqual(one, 2);
+assert.strictEqual(one, 1);