module: execute --import sequentially

PR-URL: https://github.com/nodejs/node/pull/50474
Fixes: https://github.com/nodejs/node/issues/50427
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>

doc/api/cli.md

@@ -1007,7 +1007,9 @@ added:
 
 > Stability: 1 - Experimental
 
-Preload the specified module at startup.
+Preload the specified module at startup. If the flag is provided several times,
+each module will be executed sequentially in the order they appear, starting
+with the ones provided in [`NODE_OPTIONS`][].
 
 Follows [ECMAScript module][] resolution rules.
 Use [`--require`][] to load a [CommonJS module][].

lib/internal/process/esm_loader.js

@@ -1,9 +1,5 @@
 'use strict';
 
-const {
-  SafePromiseAllReturnVoid,
-} = primordials;
-
 const { createModuleLoader } = require('internal/modules/esm/loader');
 const { getOptionValue } = require('internal/options');
 const {
@@ -23,11 +19,9 @@ module.exports = {
       const userImports = getOptionValue('--import');
       if (userImports.length > 0) {
         const parentURL = getCWDURL().href;
-        await SafePromiseAllReturnVoid(userImports, (specifier) => esmLoader.import(
+        for (let i = 0; i < userImports.length; i++) {
-          specifier,
+          await esmLoader.import(userImports[i], parentURL, kEmptyObject);
-          parentURL,
+        }
-          kEmptyObject,
-        ));
       } else {
         esmLoader.forceLoadHooks();
       }

test/es-module/test-esm-import-flag.mjs

@@ -182,4 +182,37 @@ describe('import modules using --import', { concurrency: true }, () => {
     assert.strictEqual(code, 0);
     assert.strictEqual(signal, null);
   });
+
+  it('should import files sequentially', async () => {
+    const { code, signal, stderr, stdout } = await spawnPromisified(
+      execPath,
+      [
+        '--import', fixtures.fileURL('es-modules', 'esm-top-level-await.mjs'),
+        '--import', fixtures.fileURL('es-modules', 'print-3.mjs'),
+        fixtures.path('empty.js'),
+      ]
+    );
+
+    assert.strictEqual(stderr, '');
+    assert.match(stdout, /^1\r?\n2\r?\n3\r?\n$/);
+    assert.strictEqual(code, 0);
+    assert.strictEqual(signal, null);
+  });
+
+  it('should import files from the env before ones from the CLI', async () => {
+    const { code, signal, stderr, stdout } = await spawnPromisified(
+      execPath,
+      [
+        '--import', fixtures.fileURL('es-modules', 'print-3.mjs'),
+        fixtures.path('empty.js'),
+      ],
+      { env: { ...process.env, NODE_OPTIONS: `--import ${JSON.stringify(fixtures.fileURL('es-modules', 'esm-top-level-await.mjs'))}` } }
+    );
+
+    assert.strictEqual(stderr, '');
+    assert.match(stdout, /^1\r?\n2\r?\n3\r?\n$/);
+    assert.strictEqual(code, 0);
+    assert.strictEqual(signal, null);
+
+  });
 });

test/fixtures/es-modules/esm-top-level-await.mjs

@@ -1,5 +1,7 @@
-import { setImmediate } from 'node:timers/promises';
+import { setTimeout } from 'node:timers/promises';
 
-await setImmediate();
+// Waiting some arbitrary amount of time to make sure other tasks won't start
+// executing in the mean time.
+await setTimeout(9);
 console.log(1);
 console.log(2);