1 files changed, 36 insertions, 30 deletions

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index a8dd3bbaa3..a28383690a 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -69,9 +69,14 @@ const {
   ERR_REQUIRE_ESM
 } = require('internal/errors').codes;
 const { validateString } = require('internal/validators');
+const {
+  resolveMainPath,
+  shouldUseESMLoader,
+  runMainESM
+} = require('internal/bootstrap/pre_execution');
 const pendingDeprecation = getOptionValue('--pending-deprecation');
 
-module.exports = { wrapSafe, Module };
+module.exports = { wrapSafe, Module, toRealPath, readPackageScope };
 
 let asyncESM, ModuleJob, ModuleWrap, kInstantiated;
 
@@ -810,6 +815,10 @@ Module.prototype.load = function(filename) {
   this.paths = Module._nodeModulePaths(path.dirname(filename));
 
   const extension = findLongestRegisteredExtension(filename);
+  // allow .mjs to be overridden
+  if (filename.endsWith('.mjs') && !Module._extensions['.mjs']) {
+    throw new ERR_REQUIRE_ESM(filename);
+  }
   Module._extensions[extension](this, filename);
   this.loaded = true;
 
@@ -823,14 +832,19 @@ Module.prototype.load = function(filename) {
     if (module !== undefined && module.module !== undefined) {
       if (module.module.getStatus() >= kInstantiated)
         module.module.setExport('default', exports);
-    } else { // preemptively cache
+    } else {
+      // Preemptively cache
+      // We use a function to defer promise creation for async hooks.
       ESMLoader.moduleMap.set(
         url,
-        new ModuleJob(ESMLoader, 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 */)
       );
     }
   }
@@ -859,7 +873,7 @@ Module.prototype.require = function(id) {
 var resolvedArgv;
 let hasPausedEntry = false;
 
-function wrapSafe(filename, content) {
+function wrapSafe(filename, content, cjsModuleInstance) {
   if (patched) {
     const wrapper = Module.wrap(content);
     return vm.runInThisContext(wrapper, {
@@ -867,7 +881,7 @@ function wrapSafe(filename, content) {
       lineOffset: 0,
       displayErrors: true,
       importModuleDynamically: experimentalModules ? async (specifier) => {
-        const loader = await asyncESM.loaderPromise;
+        const loader = asyncESM.ESMLoader;
         return loader.import(specifier, normalizeReferrerURL(filename));
       } : undefined,
     });
@@ -892,9 +906,8 @@ function wrapSafe(filename, content) {
       ]
     );
   } catch (err) {
-    if (experimentalModules) {
+    if (experimentalModules && process.mainModule === cjsModuleInstance)
       enrichCJSError(err);
-    }
     throw err;
   }
 
@@ -902,7 +915,7 @@ function wrapSafe(filename, content) {
     const { callbackMap } = internalBinding('module_wrap');
     callbackMap.set(compiled.cacheKey, {
       importModuleDynamically: async (specifier) => {
-        const loader = await asyncESM.loaderPromise;
+        const loader = asyncESM.ESMLoader;
         return loader.import(specifier, normalizeReferrerURL(filename));
       }
     });
@@ -925,7 +938,7 @@ Module.prototype._compile = function(content, filename) {
   }
 
   maybeCacheSourceMap(filename, content, this);
-  const compiledWrapper = wrapSafe(filename, content);
+  const compiledWrapper = wrapSafe(filename, content, this);
 
   var inspectorWrapper = null;
   if (getOptionValue('--inspect-brk') && process._eval == null) {
@@ -981,7 +994,11 @@ Module._extensions['.js'] = function(module, filename) {
           'files in that package scope as ES modules.\nInstead rename ' +
           `${basename} to end in .cjs, change the requiring code to use ` +
           'import(), or remove "type": "module" from ' +
-          `${path.resolve(pkg.path, 'package.json')}.`
+          `${path.resolve(pkg.path, 'package.json')}.`,
+          undefined,
+          undefined,
+          undefined,
+          true
         );
         warnRequireESM = false;
       }
@@ -1024,26 +1041,15 @@ Module._extensions['.node'] = function(module, filename) {
   return process.dlopen(module, path.toNamespacedPath(filename));
 };
 
-Module._extensions['.mjs'] = function(module, filename) {
-  throw new ERR_REQUIRE_ESM(filename);
-};
-
 // Bootstrap main module.
-Module.runMain = function() {
-  // Load the main module--the command line argument.
-  if (experimentalModules) {
-    asyncESM.loaderPromise.then((loader) => {
-      return loader.import(pathToFileURL(process.argv[1]).href);
-    })
-    .catch((e) => {
-      internalBinding('errors').triggerUncaughtException(
-        e,
-        true /* fromPromise */
-      );
-    });
-    return;
+Module.runMain = function(main = process.argv[1]) {
+  const resolvedMain = resolveMainPath(main);
+  const useESMLoader = shouldUseESMLoader(resolvedMain);
+  if (useESMLoader) {
+    runMainESM(resolvedMain || main);
+  } else {
+    Module._load(main, null, true);
   }
-  Module._load(process.argv[1], null, true);
 };
 
 function createRequireFromPath(filename) {
@@ -1164,7 +1170,7 @@ Module.Module = Module;
 
 // We have to load the esm things after module.exports!
 if (experimentalModules) {
-  asyncESM = require('internal/process/esm_loader');
   ModuleJob = require('internal/modules/esm/module_job');
+  asyncESM = require('internal/process/esm_loader');
   ({ ModuleWrap, kInstantiated } = internalBinding('module_wrap'));
 }