Use synchronous import.meta.resolve

Gulpfile.mjs

@@ -763,7 +763,7 @@ gulp.task("build-babel", () => buildBabel(true, /* exclude */ libBundles));
 
 gulp.task("build-vendor", async () => {
   const input = fileURLToPath(
-    await importMetaResolve("import-meta-resolve", import.meta.url)
+    importMetaResolve("import-meta-resolve", import.meta.url)
   );
   const output = "./packages/babel-core/src/vendor/import-meta-resolve.js";
 

babel.config.js

@@ -182,7 +182,6 @@ module.exports = function (api) {
       ["@babel/proposal-object-rest-spread", { useBuiltIns: true }],
 
       convertESM ? "@babel/proposal-export-namespace-from" : null,
-      convertESM ? pluginImportMetaUrl : null,
 
       pluginPackageJsonMacro,
 
@@ -276,6 +275,12 @@ module.exports = function (api) {
           ],
         ],
       },
+      convertESM && {
+        exclude: [
+          "./packages/babel-core/src/config/files/import-meta-resolve.ts",
+        ].map(normalize),
+        plugins: [pluginImportMetaUrl],
+      },
       {
         test: sources.map(source => normalize(source.replace("/src", "/test"))),
         plugins: [

package.json

@@ -58,7 +58,7 @@
     "gulp-filter": "^7.0.0",
     "gulp-plumber": "^1.2.1",
     "husky": "^7.0.4",
-    "import-meta-resolve": "^1.1.1",
+    "import-meta-resolve": "^3.0.0",
     "jest": "^29.0.1",
     "jest-light-runner": "^0.4.0",
     "jest-worker": "^29.0.1",

packages/babel-core/src/config/files/import-meta-resolve.ts

@@ -1,48 +1,28 @@
-import { createRequire } from "module";
 import { resolve as polyfill } from "../../vendor/import-meta-resolve";
 
-const require = createRequire(import.meta.url);
+declare const USE_ESM: boolean;
 
-let import_;
-try {
-  // Node < 13.3 doesn't support import() syntax.
-  import_ = require("./import.cjs");
-} catch {}
+let importMetaResolve: ImportMeta["resolve"];
 
-// import.meta.resolve is only available in ESM, but this file is compiled to CJS.
-// We can extract it using dynamic import.
-const importMetaResolveP: Promise<ImportMeta["resolve"]> =
-  import_ &&
-  // Due to a Node.js/V8 bug (https://github.com/nodejs/node/issues/35889), we cannot
-  // use always dynamic import because it segfaults when running in a Node.js `vm` context,
-  // which is used by the default Jest environment and by webpack-cli.
-  //
-  // However, import.meta.resolve is experimental and only enabled when Node.js is run
-  // with the `--experimental-import-meta-resolve` flag: we can avoid calling import()
-  // when that flag is not enabled, so that the default behavior never segfaults.
-  //
-  // Hopefully, before Node.js unflags import.meta.resolve, either:
-  // - we will move to ESM, so that we have direct access to import.meta.resolve, or
-  // - the V8 bug will be fixed so that we can safely use dynamic import by default.
-  //
-  // I (@nicolo-ribaudo) am really annoyed by this bug, because there is no known
-  // work-around other than "don't use dynamic import if you are running in a `vm` context",
-  // but there is no reliable way to detect it (you cannot try/catch segfaults).
-  //
-  // This is the only place where we *need* to use dynamic import because we need to access
-  // an ES module. All the other places will first try using require() and *then*, if
-  // it throws because it's a module, will fallback to import().
-  process.execArgv.includes("--experimental-import-meta-resolve")
-    ? import_("data:text/javascript,export default import.meta.resolve").then(
-        (m: { default: ImportMeta["resolve"] | undefined }) =>
-          m.default || polyfill,
-        () => polyfill,
-      )
-    : Promise.resolve(polyfill);
+if (USE_ESM) {
+  // Node.js < 20, when using the `--experimental-import-meta-resolve` flag,
+  // have an asynchronous implementation of import.meta.resolve.
+  if (
+    typeof import.meta.resolve === "function" &&
+    typeof import.meta.resolve(import.meta.url) === "string"
+  ) {
+    importMetaResolve = import.meta.resolve;
+  } else {
+    importMetaResolve = polyfill;
+  }
+} else {
+  importMetaResolve = polyfill;
+}
 
-export default async function resolve(
-  specifier: Parameters<ImportMeta["resolve"]>[0],
-  parent?: Parameters<ImportMeta["resolve"]>[1],
-): ReturnType<ImportMeta["resolve"]> {
-  return (await importMetaResolveP)(specifier, parent);
+export default function resolve(
+  specifier: string,
+  parent?: string | URL,
+): string {
+  // @ts-expect-error: TS defines import.meta.resolve as returning a promises
+  return importMetaResolve(specifier, parent);
 }

packages/babel-core/src/config/files/index.ts

@@ -21,10 +21,9 @@ export type {
   RelativeConfig,
   FilePackageData,
 } from "./types";
-export { loadPlugin, loadPreset } from "./plugins";
-
-import gensync from "gensync";
-import * as plugins from "./plugins";
-
-export const resolvePlugin = gensync(plugins.resolvePlugin).sync;
-export const resolvePreset = gensync(plugins.resolvePreset).sync;
+export {
+  loadPlugin,
+  loadPreset,
+  resolvePlugin,
+  resolvePreset,
+} from "./plugins";

packages/babel-core/src/config/files/plugins.ts

@@ -4,7 +4,7 @@
 
 import buildDebug from "debug";
 import path from "path";
-import gensync, { type Handler } from "gensync";
+import type { Handler } from "gensync";
 import { isAsync } from "../../gensync-utils/async";
 import loadCodeDefault, { supportsESM } from "./module-types";
 import { fileURLToPath, pathToFileURL } from "url";
@@ -27,21 +27,14 @@ const OTHER_PRESET_ORG_RE =
   /^(@(?!babel\/)[^/]+\/)(?![^/]*babel-preset(?:-|\/|$)|[^/]+\/)/;
 const OTHER_ORG_DEFAULT_RE = /^(@(?!babel$)[^/]+)$/;
 
-export function* resolvePlugin(name: string, dirname: string): Handler<string> {
-  // eslint-disable-next-line @typescript-eslint/no-use-before-define
-  return yield* resolveStandardizedName("plugin", name, dirname);
-}
-
-export function* resolvePreset(name: string, dirname: string): Handler<string> {
-  // eslint-disable-next-line @typescript-eslint/no-use-before-define
-  return yield* resolveStandardizedName("preset", name, dirname);
-}
+export const resolvePlugin = resolveStandardizedName.bind(null, "plugin");
+export const resolvePreset = resolveStandardizedName.bind(null, "preset");
 
 export function* loadPlugin(
   name: string,
   dirname: string,
 ): Handler<{ filepath: string; value: unknown }> {
-  const filepath = yield* resolvePlugin(name, dirname);
+  const filepath = resolvePlugin(name, dirname, yield* isAsync());
 
   const value = yield* requireModule("plugin", filepath);
   debug("Loaded plugin %o from %o.", name, dirname);
@@ -53,7 +46,7 @@ export function* loadPreset(
   name: string,
   dirname: string,
 ): Handler<{ filepath: string; value: unknown }> {
-  const filepath = yield* resolvePreset(name, dirname);
+  const filepath = resolvePreset(name, dirname, yield* isAsync());
 
   const value = yield* requireModule("preset", filepath);
 
@@ -122,22 +115,26 @@ function* resolveAlternativesHelper(
 }
 
 function tryRequireResolve(
-  id: Parameters<RequireResolve>[0],
-  { paths: [dirname] }: Parameters<RequireResolve>[1],
+  id: string,
+  dirname: string | undefined,
 ): Result<string> {
   try {
-    return { error: null, value: require.resolve(id, { paths: [dirname] }) };
+    if (dirname) {
+      return { error: null, value: require.resolve(id, { paths: [dirname] }) };
+    } else {
+      return { error: null, value: require.resolve(id) };
+    }
   } catch (error) {
     return { error, value: null };
   }
 }
 
-async function tryImportMetaResolve(
+function tryImportMetaResolve(
   id: Parameters<ImportMeta["resolve"]>[0],
   options: Parameters<ImportMeta["resolve"]>[1],
-): Promise<Result<string>> {
+): Result<string> {
   try {
-    return { error: null, value: await importMetaResolve(id, options) };
+    return { error: null, value: importMetaResolve(id, options) };
   } catch (error) {
     return { error, value: null };
   }
@@ -151,11 +148,11 @@ function resolveStandardizedNameForRequire(
   const it = resolveAlternativesHelper(type, name);
   let res = it.next();
   while (!res.done) {
-    res = it.next(tryRequireResolve(res.value, { paths: [dirname] }));
+    res = it.next(tryRequireResolve(res.value, dirname));
   }
   return res.value;
 }
-async function resolveStandardizedNameForImport(
+function resolveStandardizedNameForImport(
   type: "plugin" | "preset",
   name: string,
   dirname: string,
@@ -167,36 +164,33 @@ async function resolveStandardizedNameForImport(
   const it = resolveAlternativesHelper(type, name);
   let res = it.next();
   while (!res.done) {
-    res = it.next(await tryImportMetaResolve(res.value, parentUrl));
+    res = it.next(tryImportMetaResolve(res.value, parentUrl));
   }
   return fileURLToPath(res.value);
 }
 
-const resolveStandardizedName = gensync<
-  [type: "plugin" | "preset", name: string, dirname?: string],
-  string
->({
-  sync(type, name, dirname = process.cwd()) {
+function resolveStandardizedName(
+  type: "plugin" | "preset",
+  name: string,
+  dirname: string,
+  resolveESM: boolean,
+) {
+  if (!supportsESM || !resolveESM) {
     return resolveStandardizedNameForRequire(type, name, dirname);
-  },
-  async async(type, name, dirname = process.cwd()) {
-    if (!supportsESM) {
-      return resolveStandardizedNameForRequire(type, name, dirname);
-    }
+  }
 
+  try {
+    return resolveStandardizedNameForImport(type, name, dirname);
+  } catch (e) {
     try {
-      return await resolveStandardizedNameForImport(type, name, dirname);
-    } catch (e) {
-      try {
-        return resolveStandardizedNameForRequire(type, name, dirname);
-      } catch (e2) {
-        if (e.type === "MODULE_NOT_FOUND") throw e;
-        if (e2.type === "MODULE_NOT_FOUND") throw e2;
-        throw e;
-      }
+      return resolveStandardizedNameForRequire(type, name, dirname);
+    } catch (e2) {
+      if (e.type === "MODULE_NOT_FOUND") throw e;
+      if (e2.type === "MODULE_NOT_FOUND") throw e2;
+      throw e;
     }
-  },
-});
+  }
+}
 
 if (!process.env.BABEL_8_BREAKING) {
   // eslint-disable-next-line no-var

yarn.lock

@@ -6087,7 +6087,7 @@ __metadata:
     gulp-filter: ^7.0.0
     gulp-plumber: ^1.2.1
     husky: ^7.0.4
-    import-meta-resolve: ^1.1.1
+    import-meta-resolve: ^3.0.0
     jest: ^29.0.1
     jest-light-runner: ^0.4.0
     jest-worker: ^29.0.1
@@ -6506,15 +6506,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"builtins@npm:^4.0.0":
-  version: 4.0.0
-  resolution: "builtins@npm:4.0.0"
-  dependencies:
-    semver: ^7.0.0
-  checksum: 3c8b3b96ed88dd8e21286a3590292862ad62a59085bbcd77a4470848fed0f59fcd67f366afdf9ca8d7e77abce7ccf336bf662c12ead949294aa03bc563a57a1c
-  languageName: node
-  linkType: hard
-
 "c8@npm:^7.12.0":
   version: 7.12.0
   resolution: "c8@npm:7.12.0"
@@ -9606,12 +9597,10 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"import-meta-resolve@npm:^1.1.1":
-  version: 1.1.1
-  resolution: "import-meta-resolve@npm:1.1.1"
-  dependencies:
-    builtins: ^4.0.0
-  checksum: 2024161e169c45ed25a9f51d984a432a9cc342c35737f9410266bab237ca2f756c1f80c15e2297df83c92f585743d5105291f2ad24094a513f804c6023ea1472
+"import-meta-resolve@npm:^3.0.0":
+  version: 3.0.0
+  resolution: "import-meta-resolve@npm:3.0.0"
+  checksum: d0428cd14915ee0093b995dc5bbc70bd01cc668822f52b62af98f728e5d6a08724f07e6aa9f5fae002d5eecbf6ec2cdcd379bf4869dd1b353bd080693f91e394
   languageName: node
   linkType: hard
 
@@ -13611,7 +13600,7 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"semver@npm:^7.0.0, semver@npm:^7.3.2, semver@npm:^7.3.5, semver@npm:^7.3.7":
+"semver@npm:^7.3.2, semver@npm:^7.3.5, semver@npm:^7.3.7":
   version: 7.3.7
   resolution: "semver@npm:7.3.7"
   dependencies: