From 90b634a5a5bd1b4131b297fedc366777f174a091 Mon Sep 17 00:00:00 2001
From: Jacob Smith <3012099+JakobJingleheimer@users.noreply.github.com>
Date: Sat, 18 Jun 2022 19:22:57 +0200
Subject: [PATCH] esm: convert `resolve` hook to synchronous

PR-URL: https://github.com/nodejs/node/pull/43363
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
---
 doc/api/esm.md                                | 29 ++++--
 .../modules/esm/initialize_import_meta.js     | 26 ++---
 lib/internal/modules/esm/loader.js            | 95 +++++++++++++------
 lib/internal/modules/esm/resolve.js           |  6 +-
 .../test-esm-import-meta-resolve.mjs          | 70 ++++++++------
 test/es-module/test-esm-loader-chaining.mjs   | 26 +++++
 test/es-module/test-esm-loader-search.js      |  4 +-
 test/es-module/test-esm-resolve-type.js       | 16 ++--
 .../builtin-named-exports-loader.mjs          |  4 +-
 .../es-module-loaders/hook-resolve-type.mjs   |  4 +-
 .../loader-invalid-format.mjs                 |  2 +-
 .../es-module-loaders/loader-invalid-url.mjs  |  4 +-
 .../es-module-loaders/loader-resolve-42.mjs   |  2 +-
 .../loader-resolve-async-fn.mjs               |  3 +
 .../loader-resolve-bad-next-context.mjs       |  2 +-
 .../loader-resolve-bad-next-specifier.mjs     |  2 +-
 .../es-module-loaders/loader-resolve-foo.mjs  |  2 +-
 .../loader-resolve-incomplete.mjs             |  2 +-
 .../loader-resolve-multiple-next-calls.mjs    |  6 +-
 .../loader-resolve-next-modified.mjs          |  4 +-
 ...oader-resolve-passing-modified-context.mjs |  2 +-
 .../loader-resolve-passthru.mjs               |  2 +-
 ...der-resolve-receiving-modified-context.mjs |  2 +-
 .../loader-resolve-shortcircuit.mjs           |  2 +-
 .../es-module-loaders/loader-shared-dep.mjs   |  4 +-
 .../loader-with-custom-condition.mjs          |  4 +-
 .../es-module-loaders/loader-with-dep.mjs     |  4 +-
 .../missing-dynamic-instantiate-hook.mjs      |  4 +-
 .../es-module-loaders/mock-loader.mjs         |  4 +-
 .../not-found-assert-loader.mjs               |  6 +-
 30 files changed, 216 insertions(+), 127 deletions(-)
 create mode 100644 test/fixtures/es-module-loaders/loader-resolve-async-fn.mjs

diff --git a/doc/api/esm.md b/doc/api/esm.md
index 9f80dcb094e607..c5ef7eb863f6b7 100644
--- a/doc/api/esm.md
+++ b/doc/api/esm.md
@@ -324,6 +324,9 @@ added:
   - v13.9.0
   - v12.16.2
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/43363
+    description: Convert from asynchronous to synchronous.
   - version:
       - v16.2.0
       - v14.18.0
@@ -339,15 +342,19 @@ command flag enabled.
 * `specifier` {string} The module specifier to resolve relative to `parent`.
 * `parent` {string|URL} The absolute parent module URL to resolve from. If none
   is specified, the value of `import.meta.url` is used as the default.
-* Returns: {Promise}
+* Returns: {string}
 
 Provides a module-relative resolution function scoped to each module, returning
-the URL string.
+the URL string. In alignment with browser behavior, this now returns
+synchronously.
+
+> **Caveat** This can result in synchronous file-system operations, which
+> can impact performance similarly to `require.resolve`.
 
 <!-- eslint-skip -->
 
 ```js
-const dependencyAsset = await import.meta.resolve('component-lib/asset.css');
+const dependencyAsset = import.meta.resolve('component-lib/asset.css');
 ```
 
 `import.meta.resolve` also accepts a second argument which is the parent module
@@ -356,11 +363,11 @@ from which to resolve from:
 <!-- eslint-skip -->
 
 ```js
-await import.meta.resolve('./dep', import.meta.url);
+import.meta.resolve('./dep', import.meta.url);
 ```
 
-This function is asynchronous because the ES module resolver in Node.js is
-allowed to be asynchronous.
+This function is synchronous because the ES module resolver in Node.js is
+synchronous.
 
 ## Interoperability with CommonJS
 
@@ -731,6 +738,9 @@ prevent unintentional breaks in the chain.
 
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/43363
+    description: Convert hook from asynchronous to synchronous.
   - version: REPLACEME
     pr-url: https://github.com/nodejs/node/pull/42623
     description: Add support for chaining resolve hooks. Each hook must either
@@ -764,6 +774,9 @@ changes:
     terminate the chain of `resolve` hooks. **Default:** `false`
   * `url` {string} The absolute URL to which this input resolves
 
+> **Caveat** A resolve hook can contain synchronous file-system operations
+> (as `defaultResolveHook()` does), which can impact performance.
+
 The `resolve` hook chain is responsible for resolving file URL for a given
 module specifier and parent URL, and optionally its format (such as `'module'`)
 as a hint to the `load` hook. If a format is specified, the `load` hook is
@@ -790,7 +803,7 @@ Node.js module specifier resolution behavior_ when calling `defaultResolve`, the
 `context.conditions` array originally passed into the `resolve` hook.
 
 ```js
-export async function resolve(specifier, context, nextResolve) {
+export function resolve(specifier, context, nextResolve) {
   const { parentURL = null } = context;
 
   if (Math.random() > 0.5) { // Some condition.
@@ -1089,7 +1102,7 @@ const baseURL = pathToFileURL(`${cwd()}/`).href;
 // CoffeeScript files end in .coffee, .litcoffee, or .coffee.md.
 const extensionsRegex = /\.coffee$|\.litcoffee$|\.coffee\.md$/;
 
-export async function resolve(specifier, context, nextResolve) {
+export function resolve(specifier, context, nextResolve) {
   if (extensionsRegex.test(specifier)) {
     const { parentURL = baseURL } = context;
 
diff --git a/lib/internal/modules/esm/initialize_import_meta.js b/lib/internal/modules/esm/initialize_import_meta.js
index d6be06f23e1493..d8e8fe587c413e 100644
--- a/lib/internal/modules/esm/initialize_import_meta.js
+++ b/lib/internal/modules/esm/initialize_import_meta.js
@@ -3,21 +3,23 @@
 const { getOptionValue } = require('internal/options');
 const experimentalImportMetaResolve =
   getOptionValue('--experimental-import-meta-resolve');
-const {
-  PromisePrototypeThen,
-  PromiseReject,
-} = primordials;
 const asyncESM = require('internal/process/esm_loader');
 
 function createImportMetaResolve(defaultParentUrl) {
-  return async function resolve(specifier, parentUrl = defaultParentUrl) {
-    return PromisePrototypeThen(
-      asyncESM.esmLoader.resolve(specifier, parentUrl),
-      ({ url }) => url,
-      (error) => (
-        error.code === 'ERR_UNSUPPORTED_DIR_IMPORT' ?
-          error.url : PromiseReject(error))
-    );
+  return function resolve(specifier, parentUrl = defaultParentUrl) {
+    let url;
+
+    try {
+      ({ url } = asyncESM.esmLoader.resolve(specifier, parentUrl));
+    } catch (error) {
+      if (error.code === 'ERR_UNSUPPORTED_DIR_IMPORT') {
+        ({ url } = error);
+      } else {
+        throw error;
+      }
+    }
+
+    return url;
   };
 }
 
diff --git a/lib/internal/modules/esm/loader.js b/lib/internal/modules/esm/loader.js
index f81ffa8e31cf22..ef9b32f4deb8ed 100644
--- a/lib/internal/modules/esm/loader.js
+++ b/lib/internal/modules/esm/loader.js
@@ -15,6 +15,8 @@ const {
   ObjectDefineProperty,
   ObjectSetPrototypeOf,
   PromiseAll,
+  PromiseResolve,
+  PromisePrototypeThen,
   ReflectApply,
   RegExpPrototypeExec,
   SafeArrayIterator,
@@ -109,12 +111,14 @@ let emittedSpecifierResolutionWarning = false;
  * position in the hook chain.
  * @param {string} meta.hookName The kind of hook the chain is (ex 'resolve')
  * @param {boolean} meta.shortCircuited Whether a hook signaled a short-circuit.
- * @param {(hookErrIdentifier, hookArgs) => void} validate A wrapper function
+ * @param {object} validators A wrapper function
  *  containing all validation of a custom loader hook's intermediary output. Any
  *  validation within MUST throw.
+ * @param {(hookErrIdentifier, hookArgs) => void} validators.validateArgs
+ * @param {(hookErrIdentifier, output) => void} validators.validateOutput
  * @returns {function next<HookName>(...hookArgs)} The next hook in the chain.
  */
-function nextHookFactory(chain, meta, validate) {
+function nextHookFactory(chain, meta, { validateArgs, validateOutput }) {
   // First, prepare the current
   const { hookName } = meta;
   const {
@@ -137,7 +141,7 @@ function nextHookFactory(chain, meta, validate) {
     // factory generates the next link in the chain.
     meta.hookIndex--;
 
-    nextNextHook = nextHookFactory(chain, meta, validate);
+    nextNextHook = nextHookFactory(chain, meta, { validateArgs, validateOutput });
   } else {
     // eslint-disable-next-line func-name-matching
     nextNextHook = function chainAdvancedTooFar() {
@@ -148,21 +152,36 @@ function nextHookFactory(chain, meta, validate) {
   }
 
   return ObjectDefineProperty(
-    async (...args) => {
+    (...args) => {
       // Update only when hook is invoked to avoid fingering the wrong filePath
       meta.hookErrIdentifier = `${hookFilePath} '${hookName}'`;
 
-      validate(`${meta.hookErrIdentifier} hook's ${nextHookName}()`, args);
+      validateArgs(`${meta.hookErrIdentifier} hook's ${nextHookName}()`, args);
+
+      const outputErrIdentifier = `${chain[generatedHookIndex].url} '${hookName}' hook's ${nextHookName}()`;
 
       // Set when next<HookName> is actually called, not just generated.
       if (generatedHookIndex === 0) { meta.chainFinished = true; }
 
       ArrayPrototypePush(args, nextNextHook);
-      const output = await ReflectApply(hook, undefined, args);
+      const output = ReflectApply(hook, undefined, args);
+
+      validateOutput(outputErrIdentifier, output);
 
-      if (output?.shortCircuit === true) { meta.shortCircuited = true; }
-      return output;
+      function checkShortCircuited(output) {
+        if (output?.shortCircuit === true) { meta.shortCircuited = true; }
+
+        return output;
+      }
+
+      if (meta.isChainAsync) {
+        return PromisePrototypeThen(
+          PromiseResolve(output),
+          checkShortCircuited,
+        );
+      }
 
+      return checkShortCircuited(output);
     },
     'name',
     { __proto__: null, value: nextHookName },
@@ -421,8 +440,11 @@ class ESMLoader {
       );
     }
 
-    const { format, url } =
-      await this.resolve(specifier, parentURL, importAssertionsForResolve);
+    const { format, url } = this.resolve(
+      specifier,
+      parentURL,
+      importAssertionsForResolve,
+    );
 
     let job = this.moduleMap.get(url, importAssertions.type);
 
@@ -557,10 +579,11 @@ class ESMLoader {
       hookErrIdentifier: '',
       hookIndex: chain.length - 1,
       hookName: 'load',
+      isChainAsync: true,
       shortCircuited: false,
     };
 
-    const validate = (hookErrIdentifier, { 0: nextUrl, 1: ctx }) => {
+    const validateArgs = (hookErrIdentifier, { 0: nextUrl, 1: ctx }) => {
       if (typeof nextUrl !== 'string') {
         // non-strings can be coerced to a url string
         // validateString() throws a less-specific error
@@ -586,19 +609,22 @@ class ESMLoader {
 
       validateObject(ctx, `${hookErrIdentifier} context`);
     };
+    const validateOutput = (hookErrIdentifier, output) => {
+      if (typeof output !== 'object') { // [2]
+        throw new ERR_INVALID_RETURN_VALUE(
+          'an object',
+          hookErrIdentifier,
+          output,
+        );
+      }
+    };
 
-    const nextLoad = nextHookFactory(chain, meta, validate);
+    const nextLoad = nextHookFactory(chain, meta, { validateArgs, validateOutput });
 
     const loaded = await nextLoad(url, context);
     const { hookErrIdentifier } = meta; // Retrieve the value after all settled
 
-    if (typeof loaded !== 'object') { // [2]
-      throw new ERR_INVALID_RETURN_VALUE(
-        'an object',
-        hookErrIdentifier,
-        loaded,
-      );
-    }
+    validateOutput(hookErrIdentifier, loaded);
 
     if (loaded?.shortCircuit === true) { meta.shortCircuited = true; }
 
@@ -778,7 +804,7 @@ class ESMLoader {
    *                                              statement or expression.
    * @returns {{ format: string, url: URL['href'] }}
    */
-  async resolve(
+  resolve(
     originalSpecifier,
     parentURL,
     importAssertions = ObjectCreate(null)
@@ -802,16 +828,16 @@ class ESMLoader {
       hookErrIdentifier: '',
       hookIndex: chain.length - 1,
       hookName: 'resolve',
+      isChainAsync: false,
       shortCircuited: false,
     };
-
     const context = {
       conditions: DEFAULT_CONDITIONS,
       importAssertions,
       parentURL,
     };
-    const validate = (hookErrIdentifier, { 0: suppliedSpecifier, 1: ctx }) => {
 
+    const validateArgs = (hookErrIdentifier, { 0: suppliedSpecifier, 1: ctx }) => {
       validateString(
         suppliedSpecifier,
         `${hookErrIdentifier} specifier`,
@@ -819,19 +845,26 @@ class ESMLoader {
 
       validateObject(ctx, `${hookErrIdentifier} context`);
     };
+    const validateOutput = (hookErrIdentifier, output) => {
+      if (
+        typeof output !== 'object' || // [2]
+        output === null ||
+        (output.url == null && typeof output.then === 'function')
+      ) {
+        throw new ERR_INVALID_RETURN_VALUE(
+          'an object',
+          hookErrIdentifier,
+          output,
+        );
+      }
+    };
 
-    const nextResolve = nextHookFactory(chain, meta, validate);
+    const nextResolve = nextHookFactory(chain, meta, { validateArgs, validateOutput });
 
-    const resolution = await nextResolve(originalSpecifier, context);
+    const resolution = nextResolve(originalSpecifier, context);
     const { hookErrIdentifier } = meta; // Retrieve the value after all settled
 
-    if (typeof resolution !== 'object') { // [2]
-      throw new ERR_INVALID_RETURN_VALUE(
-        'an object',
-        hookErrIdentifier,
-        resolution,
-      );
-    }
+    validateOutput(hookErrIdentifier, resolution);
 
     if (resolution?.shortCircuit === true) { meta.shortCircuited = true; }
 
diff --git a/lib/internal/modules/esm/resolve.js b/lib/internal/modules/esm/resolve.js
index 79ea42233b66a0..1aacfb60753258 100644
--- a/lib/internal/modules/esm/resolve.js
+++ b/lib/internal/modules/esm/resolve.js
@@ -1081,7 +1081,7 @@ function throwIfUnsupportedURLScheme(parsed, experimentalNetworkImports) {
   }
 }
 
-async function defaultResolve(specifier, context = {}) {
+function defaultResolve(specifier, context = {}) {
   let { parentURL, conditions } = context;
   if (parentURL && policy?.manifest) {
     const redirects = policy.manifest.getDependencyMapper(parentURL);
@@ -1227,11 +1227,11 @@ const {
 
 if (policy) {
   const $defaultResolve = defaultResolve;
-  module.exports.defaultResolve = async function defaultResolve(
+  module.exports.defaultResolve = function defaultResolve(
     specifier,
     context
   ) {
-    const ret = await $defaultResolve(specifier, context, $defaultResolve);
+    const ret = $defaultResolve(specifier, context);
     // This is a preflight check to avoid data exfiltration by query params etc.
     policy.manifest.mightAllow(ret.url, () =>
       new ERR_MANIFEST_DEPENDENCY_MISSING(
diff --git a/test/es-module/test-esm-import-meta-resolve.mjs b/test/es-module/test-esm-import-meta-resolve.mjs
index 1fac362172ae34..70abe272ca0421 100644
--- a/test/es-module/test-esm-import-meta-resolve.mjs
+++ b/test/es-module/test-esm-import-meta-resolve.mjs
@@ -1,37 +1,49 @@
 // Flags: --experimental-import-meta-resolve
-import { mustCall } from '../common/index.mjs';
+import '../common/index.mjs';
 import assert from 'assert';
 
 const dirname = import.meta.url.slice(0, import.meta.url.lastIndexOf('/') + 1);
 const fixtures = dirname.slice(0, dirname.lastIndexOf('/', dirname.length - 2) +
     1) + 'fixtures/';
 
-(async () => {
-  assert.strictEqual(await import.meta.resolve('./test-esm-import-meta.mjs'),
-                     dirname + 'test-esm-import-meta.mjs');
-  try {
-    await import.meta.resolve('./notfound.mjs');
-    assert.fail();
-  } catch (e) {
-    assert.strictEqual(e.code, 'ERR_MODULE_NOT_FOUND');
-  }
-  assert.strictEqual(
-    await import.meta.resolve('../fixtures/empty-with-bom.txt'),
-    fixtures + 'empty-with-bom.txt');
-  assert.strictEqual(await import.meta.resolve('../fixtures/'), fixtures);
-  assert.strictEqual(
-    await import.meta.resolve('../fixtures/', import.meta.url),
-    fixtures);
-  assert.strictEqual(
-    await import.meta.resolve('../fixtures/', new URL(import.meta.url)),
-    fixtures);
-  await Promise.all(
-    [[], {}, Symbol(), 0, 1, 1n, 1.1, () => {}, true, false].map((arg) =>
-      assert.rejects(import.meta.resolve('../fixtures/', arg), {
-        code: 'ERR_INVALID_ARG_TYPE',
-      })
-    )
+assert.strictEqual(
+  import.meta.resolve('./test-esm-import-meta.mjs'),
+  dirname + 'test-esm-import-meta.mjs',
+);
+
+assert.throws(
+  () => import.meta.resolve('./notfound.mjs'),
+  { code: 'ERR_MODULE_NOT_FOUND' },
+);
+
+assert.strictEqual(
+  import.meta.resolve('../fixtures/empty-with-bom.txt'),
+  fixtures + 'empty-with-bom.txt',
+);
+
+assert.strictEqual(
+  import.meta.resolve('../fixtures/'),
+  fixtures,
+);
+
+assert.strictEqual(
+  import.meta.resolve('../fixtures/', import.meta.url),
+  fixtures,
+);
+
+assert.strictEqual(
+  import.meta.resolve('../fixtures/', new URL(import.meta.url)),
+  fixtures,
+);
+
+[[], {}, Symbol(), 0, 1, 1n, 1.1, () => {}, true, false].forEach((arg) => {
+  assert.throws(
+    () => import.meta.resolve('../fixtures/', arg),
+    { code: 'ERR_INVALID_ARG_TYPE' },
   );
-  assert.strictEqual(await import.meta.resolve('baz/', fixtures),
-                     fixtures + 'node_modules/baz/');
-})().then(mustCall());
+});
+
+assert.strictEqual(
+  import.meta.resolve('baz/', fixtures),
+  fixtures + 'node_modules/baz/',
+);
diff --git a/test/es-module/test-esm-loader-chaining.mjs b/test/es-module/test-esm-loader-chaining.mjs
index 977c20dbbbab37..7bfe00f5ede842 100644
--- a/test/es-module/test-esm-loader-chaining.mjs
+++ b/test/es-module/test-esm-loader-chaining.mjs
@@ -165,6 +165,32 @@ const commonArgs = [
   assert.strictEqual(status, 0);
 }
 
+{ // Verify error thrown for an async resolve hook
+  const { status, stderr } = spawnSync(
+    process.execPath,
+    [
+      '--loader',
+      fixtures.fileURL('es-module-loaders', 'loader-resolve-shortcircuit.mjs'),
+      '--loader',
+      fixtures.fileURL('es-module-loaders', 'loader-resolve-42.mjs'),
+      '--loader',
+      fixtures.fileURL('es-module-loaders', 'loader-resolve-async-fn.mjs'),
+      '--loader',
+      fixtures.fileURL('es-module-loaders', 'loader-load-foo-or-42.mjs'),
+      ...commonArgs,
+    ],
+    { encoding: 'utf8' },
+  );
+
+  assert.match(stderr, /ERR_INVALID_RETURN_VALUE/);
+  assert.match(stderr, /Promise/);
+  assert.match(stderr, /loader-resolve-async-fn\.mjs/);
+  assert.match(stderr, /'resolve'/);
+  // Cannot expect stdout to be empty because detecting whether a hook has
+  // returned a promise requires the hook to be executed
+  assert.strictEqual(status, 1);
+}
+
 { // Verify error thrown for incomplete resolve chain, citing errant loader & hook
   const { status, stderr, stdout } = spawnSync(
     process.execPath,
diff --git a/test/es-module/test-esm-loader-search.js b/test/es-module/test-esm-loader-search.js
index 0440d3d7775cff..3c451409b356db 100644
--- a/test/es-module/test-esm-loader-search.js
+++ b/test/es-module/test-esm-loader-search.js
@@ -10,8 +10,8 @@ const {
   defaultResolve: resolve
 } = require('internal/modules/esm/resolve');
 
-assert.rejects(
-  resolve('target'),
+assert.throws(
+  () => resolve('target'),
   {
     code: 'ERR_MODULE_NOT_FOUND',
     name: 'Error',
diff --git a/test/es-module/test-esm-resolve-type.js b/test/es-module/test-esm-resolve-type.js
index 05e908cd32fc34..bf3b77c34f7769 100644
--- a/test/es-module/test-esm-resolve-type.js
+++ b/test/es-module/test-esm-resolve-type.js
@@ -41,10 +41,10 @@ try {
     [ '/es-modules/package-type-commonjs/index.js', 'commonjs' ],
     [ '/es-modules/package-without-type/index.js', 'commonjs' ],
     [ '/es-modules/package-without-pjson/index.js', 'commonjs' ],
-  ].forEach(async (testVariant) => {
+  ].forEach((testVariant) => {
     const [ testScript, expectedType ] = testVariant;
     const resolvedPath = path.resolve(fixtures.path(testScript));
-    const resolveResult = await resolve(url.pathToFileURL(resolvedPath));
+    const resolveResult = resolve(url.pathToFileURL(resolvedPath));
     assert.strictEqual(resolveResult.format, expectedType);
   });
 
@@ -59,7 +59,7 @@ try {
     [ 'test-module-mainmjs', 'mjs', 'module', 'module'],
     [ 'test-module-cjs', 'js', 'commonjs', 'commonjs'],
     [ 'test-module-ne', 'js', undefined, 'commonjs'],
-  ].forEach(async (testVariant) => {
+  ].forEach((testVariant) => {
     const [ moduleName,
             moduleExtenstion,
             moduleType,
@@ -89,7 +89,7 @@ try {
     fs.writeFileSync(script,
                      'export function esm-resolve-tester() {return 42}');
 
-    const resolveResult = await resolve(`${moduleName}`);
+    const resolveResult = resolve(`${moduleName}`);
     assert.strictEqual(resolveResult.format, expectedResolvedType);
 
     fs.rmSync(nmDir, { recursive: true, force: true });
@@ -102,7 +102,7 @@ try {
     }
   };
 
-  async function testDualPackageWithJsMainScriptAndModuleType() {
+  function testDualPackageWithJsMainScriptAndModuleType() {
     // Create a dummy dual package
     //
     /**
@@ -172,7 +172,7 @@ try {
     );
 
     // test the resolve
-    const resolveResult = await resolve(`${moduleName}`);
+    const resolveResult = resolve(`${moduleName}`);
     assert.strictEqual(resolveResult.format, 'module');
     assert.ok(resolveResult.url.includes('my-dual-package/es/index.js'));
   }
@@ -192,7 +192,7 @@ try {
     [ 'hmod', 'index.js', 'imp.js', 'commonjs', 'module', 'module', '#Key'],
     [ 'qhmod', 'index.js', 'imp.js', 'commonjs', 'module', 'module', '?k=v#h'],
     [ 'ts-mod-com', 'index.js', 'imp.ts', 'module', 'commonjs', undefined],
-  ].forEach(async (testVariant) => {
+  ].forEach((testVariant) => {
     const [
       moduleName,
       mainRequireScript,
@@ -240,7 +240,7 @@ try {
     );
 
     // test the resolve
-    const resolveResult = await resolve(`${moduleName}`);
+    const resolveResult = resolve(`${moduleName}`);
     assert.strictEqual(resolveResult.format, expectedResolvedFormat);
     assert.ok(resolveResult.url.endsWith(`${moduleName}/subdir/${mainImportScript}${mainSuffix}`));
   });
diff --git a/test/fixtures/es-module-loaders/builtin-named-exports-loader.mjs b/test/fixtures/es-module-loaders/builtin-named-exports-loader.mjs
index e303ec196f6c6d..ab113341582b42 100644
--- a/test/fixtures/es-module-loaders/builtin-named-exports-loader.mjs
+++ b/test/fixtures/es-module-loaders/builtin-named-exports-loader.mjs
@@ -13,8 +13,8 @@ export function globalPreload() {
 `;
 }
 
-export async function resolve(specifier, context, next) {
-  const def = await next(specifier, context);
+export function resolve(specifier, context, next) {
+  const def = next(specifier, context);
 
   if (def.url.startsWith('node:')) {
     return {
diff --git a/test/fixtures/es-module-loaders/hook-resolve-type.mjs b/test/fixtures/es-module-loaders/hook-resolve-type.mjs
index 5068d6265c57b2..86e2bffe650002 100644
--- a/test/fixtures/es-module-loaders/hook-resolve-type.mjs
+++ b/test/fixtures/es-module-loaders/hook-resolve-type.mjs
@@ -6,8 +6,8 @@ export async function load(url, context, next) {
   return next(url, context, next);
 }
 
-export async function resolve(specifier, context, next) {
-  const nextResult = await next(specifier, context);
+export function resolve(specifier, context, next) {
+  const nextResult = next(specifier, context);
   const { format } = nextResult;
 
   if (format === 'module' || specifier.endsWith('.mjs')) {
diff --git a/test/fixtures/es-module-loaders/loader-invalid-format.mjs b/test/fixtures/es-module-loaders/loader-invalid-format.mjs
index 438d50dacba433..1521e447c5d0d5 100644
--- a/test/fixtures/es-module-loaders/loader-invalid-format.mjs
+++ b/test/fixtures/es-module-loaders/loader-invalid-format.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
+export function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
   if (parentURL && specifier === '../fixtures/es-modules/test-esm-ok.mjs') {
     return {
       shortCircuit: true,
diff --git a/test/fixtures/es-module-loaders/loader-invalid-url.mjs b/test/fixtures/es-module-loaders/loader-invalid-url.mjs
index 87d1a6a564b461..f89d0eb23de510 100644
--- a/test/fixtures/es-module-loaders/loader-invalid-url.mjs
+++ b/test/fixtures/es-module-loaders/loader-invalid-url.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
+export function resolve(specifier, { parentURL, importAssertions }, nextResolve) {
   if (parentURL && specifier === '../fixtures/es-modules/test-esm-ok.mjs') {
     return {
       shortCircuit: true,
@@ -6,5 +6,5 @@ export async function resolve(specifier, { parentURL, importAssertions }, defaul
       importAssertions,
     };
   }
-  return defaultResolve(specifier, {parentURL, importAssertions}, defaultResolve);
+  return nextResolve(specifier, {parentURL, importAssertions});
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-42.mjs b/test/fixtures/es-module-loaders/loader-resolve-42.mjs
index 5c90bceed2b07e..23650893048835 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-42.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-42.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   console.log('resolve 42'); // This log is deliberate
   console.log('next<HookName>:', next.name); // This log is deliberate
 
diff --git a/test/fixtures/es-module-loaders/loader-resolve-async-fn.mjs b/test/fixtures/es-module-loaders/loader-resolve-async-fn.mjs
new file mode 100644
index 00000000000000..6cf60d403bbfb7
--- /dev/null
+++ b/test/fixtures/es-module-loaders/loader-resolve-async-fn.mjs
@@ -0,0 +1,3 @@
+export async function resolve(specifier, context, next) {
+  return next(specifier, context);
+}
diff --git a/test/fixtures/es-module-loaders/loader-resolve-bad-next-context.mjs b/test/fixtures/es-module-loaders/loader-resolve-bad-next-context.mjs
index 881f5875dd0206..1e42a6d6ddf665 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-bad-next-context.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-bad-next-context.mjs
@@ -1,3 +1,3 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   return next(specifier, []);
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-bad-next-specifier.mjs b/test/fixtures/es-module-loaders/loader-resolve-bad-next-specifier.mjs
index a23785d3d956db..a01d40ad31f1c3 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-bad-next-specifier.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-bad-next-specifier.mjs
@@ -1,3 +1,3 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   return next([], context);
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-foo.mjs b/test/fixtures/es-module-loaders/loader-resolve-foo.mjs
index 595385e12a0cf7..d19e9c271b293f 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-foo.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-foo.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   console.log('resolve foo'); // This log is deliberate
   return next('file:///foo.mjs', context);
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-incomplete.mjs b/test/fixtures/es-module-loaders/loader-resolve-incomplete.mjs
index 9eb1617f30130e..d71dc48249c9d8 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-incomplete.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-incomplete.mjs
@@ -1,4 +1,4 @@
-export async function resolve() {
+export function resolve() {
   return {
     url: 'file:///incomplete-resolve-chain.js',
   };
diff --git a/test/fixtures/es-module-loaders/loader-resolve-multiple-next-calls.mjs b/test/fixtures/es-module-loaders/loader-resolve-multiple-next-calls.mjs
index 88d333c2404a3c..7bbc9ea08fffcf 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-multiple-next-calls.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-multiple-next-calls.mjs
@@ -1,6 +1,6 @@
-export async function resolve(specifier, context, next) {
-  const { url: first } = await next(specifier, context);
-  const { url: second } = await next(specifier, context);
+export function resolve(specifier, context, next) {
+  const { url: first } = next(specifier, context);
+  const { url: second } = next(specifier, context);
 
   return {
     format: 'module',
diff --git a/test/fixtures/es-module-loaders/loader-resolve-next-modified.mjs b/test/fixtures/es-module-loaders/loader-resolve-next-modified.mjs
index a973345a82ff21..8b0d24016b3fe7 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-next-modified.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-next-modified.mjs
@@ -1,8 +1,8 @@
-export async function resolve(url, context, next) {
+export function resolve(url, context, next) {
   const {
     format,
     url: nextUrl,
-  } = await next(url, context);
+  } = next(url, context);
 
   return {
     format,
diff --git a/test/fixtures/es-module-loaders/loader-resolve-passing-modified-context.mjs b/test/fixtures/es-module-loaders/loader-resolve-passing-modified-context.mjs
index 6a92a6cd8f6a8e..1a8a7768ebccc7 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-passing-modified-context.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-passing-modified-context.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   return next(specifier, {
     ...context,
     foo: 'bar',
diff --git a/test/fixtures/es-module-loaders/loader-resolve-passthru.mjs b/test/fixtures/es-module-loaders/loader-resolve-passthru.mjs
index 1a373bab90ba57..0ce3fdf2eef941 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-passthru.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-passthru.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   console.log('resolve passthru'); // This log is deliberate
   return next(specifier, context);
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-receiving-modified-context.mjs b/test/fixtures/es-module-loaders/loader-resolve-receiving-modified-context.mjs
index 83aa83104e96e4..cf651eb57d2ac7 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-receiving-modified-context.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-receiving-modified-context.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier, context, next) {
+export function resolve(specifier, context, next) {
   console.log(context.foo); // This log is deliberate
   return next(specifier, context);
 }
diff --git a/test/fixtures/es-module-loaders/loader-resolve-shortcircuit.mjs b/test/fixtures/es-module-loaders/loader-resolve-shortcircuit.mjs
index d886b3dfcbf237..ff0346a34c2e37 100644
--- a/test/fixtures/es-module-loaders/loader-resolve-shortcircuit.mjs
+++ b/test/fixtures/es-module-loaders/loader-resolve-shortcircuit.mjs
@@ -1,4 +1,4 @@
-export async function resolve(specifier) {
+export function resolve(specifier) {
   return {
     shortCircuit: true,
     url: specifier,
diff --git a/test/fixtures/es-module-loaders/loader-shared-dep.mjs b/test/fixtures/es-module-loaders/loader-shared-dep.mjs
index 387575794c00dc..4a893686302bfb 100644
--- a/test/fixtures/es-module-loaders/loader-shared-dep.mjs
+++ b/test/fixtures/es-module-loaders/loader-shared-dep.mjs
@@ -5,7 +5,7 @@ import { createRequire } from '../../common/index.mjs';
 const require = createRequire(import.meta.url);
 const dep = require('./loader-dep.js');
 
-export function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
+export function resolve(specifier, { parentURL, importAssertions }, nextResolve) {
   assert.strictEqual(dep.format, 'module');
-  return defaultResolve(specifier, { parentURL, importAssertions }, defaultResolve);
+  return nextResolve(specifier, { parentURL, importAssertions });
 }
diff --git a/test/fixtures/es-module-loaders/loader-with-custom-condition.mjs b/test/fixtures/es-module-loaders/loader-with-custom-condition.mjs
index 3aefed51d57d3e..e8d1c638b26eff 100644
--- a/test/fixtures/es-module-loaders/loader-with-custom-condition.mjs
+++ b/test/fixtures/es-module-loaders/loader-with-custom-condition.mjs
@@ -1,6 +1,6 @@
 import { ok, deepStrictEqual } from 'assert';
 
-export async function resolve(specifier, context, defaultResolve) {
+export function resolve(specifier, context, nextResolve) {
   ok(Array.isArray(context.conditions), 'loader receives conditions array');
 
   deepStrictEqual([...context.conditions].sort(), [
@@ -9,7 +9,7 @@ export async function resolve(specifier, context, defaultResolve) {
     'node-addons',
   ]);
 
-  return defaultResolve(specifier, {
+  return nextResolve(specifier, {
     ...context,
     conditions: ['custom-condition', ...context.conditions],
   });
diff --git a/test/fixtures/es-module-loaders/loader-with-dep.mjs b/test/fixtures/es-module-loaders/loader-with-dep.mjs
index 1b5fd6c3c1642a..8a0d57e907b2ae 100644
--- a/test/fixtures/es-module-loaders/loader-with-dep.mjs
+++ b/test/fixtures/es-module-loaders/loader-with-dep.mjs
@@ -3,9 +3,9 @@ import {createRequire} from '../../common/index.mjs';
 const require = createRequire(import.meta.url);
 const dep = require('./loader-dep.js');
 
-export async function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
+export function resolve(specifier, { parentURL, importAssertions }, nextResolve) {
   return {
-    url: (await defaultResolve(specifier, { parentURL, importAssertions }, defaultResolve)).url,
+    url: (nextResolve(specifier, { parentURL, importAssertions })).url,
     format: dep.format
   };
 }
diff --git a/test/fixtures/es-module-loaders/missing-dynamic-instantiate-hook.mjs b/test/fixtures/es-module-loaders/missing-dynamic-instantiate-hook.mjs
index ec15eb0bb8fc24..b0e41dd3e5f433 100644
--- a/test/fixtures/es-module-loaders/missing-dynamic-instantiate-hook.mjs
+++ b/test/fixtures/es-module-loaders/missing-dynamic-instantiate-hook.mjs
@@ -1,10 +1,10 @@
-export function resolve(specifier, { parentURL }, defaultResolve) {
+export function resolve(specifier, { parentURL }, nextResolve) {
   if (specifier === 'test') {
     return {
       url: 'file://'
     };
   }
-  return defaultResolve(specifier, {parentURL}, defaultResolve);
+  return nextResolve(specifier, {parentURL});
 }
 
 export function getFormat(url, context, defaultGetFormat) {
diff --git a/test/fixtures/es-module-loaders/mock-loader.mjs b/test/fixtures/es-module-loaders/mock-loader.mjs
index 062be39603e851..f0b1fdf9103c92 100644
--- a/test/fixtures/es-module-loaders/mock-loader.mjs
+++ b/test/fixtures/es-module-loaders/mock-loader.mjs
@@ -168,7 +168,7 @@ export function globalPreload({port}) {
 
 
 // Rewrites node: loading to mock-facade: so that it can be intercepted
-export async function resolve(specifier, context, defaultResolve) {
+export function resolve(specifier, context, nextResolve) {
   if (specifier === 'node:mock') {
     return {
       shortCircuit: true,
@@ -176,7 +176,7 @@ export async function resolve(specifier, context, defaultResolve) {
     };
   }
   doDrainPort();
-  const def = await defaultResolve(specifier, context);
+  const def = nextResolve(specifier, context);
   if (context.parentURL?.startsWith('mock-facade:')) {
     // Do nothing, let it get the "real" module
   } else if (mockedModuleExports.has(def.url)) {
diff --git a/test/fixtures/es-module-loaders/not-found-assert-loader.mjs b/test/fixtures/es-module-loaders/not-found-assert-loader.mjs
index 5213ddedb34e8d..611354fadc3aba 100644
--- a/test/fixtures/es-module-loaders/not-found-assert-loader.mjs
+++ b/test/fixtures/es-module-loaders/not-found-assert-loader.mjs
@@ -3,13 +3,13 @@ import assert from 'assert';
 // a loader that asserts that the defaultResolve will throw "not found"
 // (skipping the top-level main of course)
 let mainLoad = true;
-export async function resolve(specifier, { parentURL, importAssertions }, defaultResolve) {
+export function resolve(specifier, { parentURL, importAssertions }, nextResolve) {
   if (mainLoad) {
     mainLoad = false;
-    return defaultResolve(specifier, {parentURL, importAssertions}, defaultResolve);
+    return nextResolve(specifier, {parentURL, importAssertions});
   }
   try {
-    await defaultResolve(specifier, {parentURL, importAssertions}, defaultResolve);
+    nextResolve(specifier, {parentURL, importAssertions});
   }
   catch (e) {
     assert.strictEqual(e.code, 'ERR_MODULE_NOT_FOUND');