esm: refactor test-esm-loader-resolve-type

PR-URL: nodejs#49493
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

test/es-module/test-esm-loader-resolve-type.mjs

@@ -16,7 +16,7 @@ try {
     { recursive: true }
   );
 
-  deepStrictEqual(await spawnPromisified(
+  const output = await spawnPromisified(
     execPath,
     [
       '--no-warnings',
@@ -29,15 +29,17 @@ try {
       console.log(JSON.stringify({ before, after }));`,
     ],
     { cwd: base },
-  ), {
+  );
+
+  deepStrictEqual(output, {
+    code: 0,
+    signal: null,
     stderr: '',
     stdout: JSON.stringify({
       before: { importedESM: 0, importedCJS: 0 },
       // Dynamic import in the eval script should increment ESM counter but not CJS counter
       after: { importedESM: 1, importedCJS: 0 },
     }) + '\n',
-    code: 0,
-    signal: null,
   });
 } finally {
   await rm(base, { recursive: true, force: true });

test/fixtures/es-module-loaders/hook-resolve-type-loader.mjs

@@ -0,0 +1,18 @@
+/** @type {MessagePort} */
+let port;
+export function initialize(data) {
+  port = data.port;
+}
+
+export async function resolve(specifier, context, next) {
+  const nextResult = await next(specifier, context);
+  const { format } = nextResult;
+
+  if (format === 'module' || specifier.endsWith('.mjs')) {
+    port.postMessage({ type: 'module' });
+  } else if (format == null || format === 'commonjs') {
+    port.postMessage({ type: 'commonjs' });
+  }
+
+  return nextResult;
+}

test/fixtures/es-module-loaders/hook-resolve-type.mjs

@@ -1,44 +1,30 @@
+import * as fixtures from '../../common/fixtures.mjs';
+import { register } from 'node:module';
+import { MessageChannel } from 'node:worker_threads';
+
 let importedESM = 0;
 let importedCJS = 0;
+export function getModuleTypeStats() {
+  return { importedESM, importedCJS };
+};
 
-export function globalPreload({ port }) {
-  port.on('message', (int32) => {
-    port.postMessage({ importedESM, importedCJS });
-    Atomics.store(int32, 0, 1);
-    Atomics.notify(int32, 0);
-  });
-  port.unref();
-  return `
-    const { receiveMessageOnPort } = getBuiltin('worker_threads');
-    global.getModuleTypeStats = async function getModuleTypeStats() {
-      const sab = new SharedArrayBuffer(4);
-      const int32 = new Int32Array(sab);
-      port.postMessage(int32);
-      // Artificial timeout to keep the event loop alive.
-      // https://bugs.chromium.org/p/v8/issues/detail?id=13238
-      // TODO(targos) Remove when V8 issue is resolved.
-      const timeout = setTimeout(() => { throw new Error('timeout'); }, 1_000);
-      await Atomics.waitAsync(int32, 0, 0).value;
-      clearTimeout(timeout);
-      return receiveMessageOnPort(port).message;
-    };
-  `;
-}
-
-export async function load(url, context, next) {
-  return next(url);
-}
+const { port1, port2 } = new MessageChannel();
 
-export async function resolve(specifier, context, next) {
-  const nextResult = await next(specifier, context);
-  const { format } = nextResult;
+register(fixtures.fileURL('es-module-loaders/hook-resolve-type-loader.mjs'), {
+  data: { port: port2 },
+  transferList: [port2],
+});
 
-  if (format === 'module' || specifier.endsWith('.mjs')) {
-    importedESM++;
-  } else if (format == null || format === 'commonjs') {
-    importedCJS++;
+port1.on('message', ({ type }) => {
+  switch (type) {
+    case 'module':
+      importedESM++;
+      break;
+    case 'commonjs':
+      importedCJS++;
+      break;
   }
+});
 
-  return nextResult;
-}
-
+port1.unref();
+port2.unref();