esm: link modules synchronously when no async loader hooks are used

When no async loader hooks are registered, perform the linking as
synchronously as possible to reduce the chance of races from the
the shared module loading cache.

Author: joyeecheung

lib/internal/modules/esm/loader.js

@@ -65,6 +65,8 @@ let debug = require('internal/util/debuglog').debuglog('esm', (fn) => {
   debug = fn;
 });
 
+const { isPromise } = require('internal/util/types');
+
 /**
  * @typedef {import('./hooks.js').HooksProxy} HooksProxy
  * @typedef {import('./module_job.js').ModuleJobBase} ModuleJobBase
@@ -592,14 +594,21 @@ class ModuleLoader {
 
   /**
    * Load a module and translate it into a ModuleWrap for ordinary imported ESM.
-   * This is run asynchronously.
+   * This may be run asynchronously if there are asynchronous module loader hooks registered.
    * @param {string} url URL of the module to be translated.
    * @param {object} loadContext See {@link load}
    * @param {boolean} isMain Whether the module to be translated is the entry point.
-   * @returns {Promise<ModuleWrap>}
+   * @returns {Promise<ModuleWrap>|ModuleWrap}
    */
-  async loadAndTranslate(url, loadContext, isMain) {
-    const { format, source } = await this.load(url, loadContext);
+  loadAndTranslate(url, loadContext, isMain) {
+    const maybePromise = this.load(url, loadContext);
+    if (isPromise(maybePromise)) {
+      return maybePromise.then((loadResult) => {
+        const { format, source } = loadResult;
+        return this.#translate(url, format, source, isMain);
+      });
+    }
+    const { format, source } = maybePromise;
     return this.#translate(url, format, source, isMain);
   }
 

lib/internal/modules/esm/module_job.js

@@ -37,6 +37,7 @@ const {
   },
 } = internalBinding('util');
 const { decorateErrorStack, kEmptyObject } = require('internal/util');
+const { isPromise } = require('internal/util/types');
 const {
   getSourceMapsSupport,
 } = require('internal/source_map/source_map_cache');
@@ -138,12 +139,11 @@ class ModuleJob extends ModuleJobBase {
     this.#loader = loader;
 
     // Expose the promise to the ModuleWrap directly for linking below.
-    if (isForRequireInImportedCJS) {
-      this.module = moduleOrModulePromise;
-      assert(this.module instanceof ModuleWrap);
-      this.modulePromise = PromiseResolve(this.module);
-    } else {
+    if (isPromise(moduleOrModulePromise)) {
       this.modulePromise = moduleOrModulePromise;
+    } else {
+      this.module = moduleOrModulePromise;
+      this.modulePromise = PromiseResolve(moduleOrModulePromise);
     }
 
     if (this.phase === kEvaluationPhase) {