esm: make process.exit() default to exit code 0

Due to a bug in top-level await implementation, it used to default to
exit code 13.

PR-URL: nodejs#41388
Fixes: nodejs#40808
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>

lib/internal/modules/esm/handle_process_exit.js

@@ -0,0 +1,12 @@
+'use strict';
+
+// Handle a Promise from running code that potentially does Top-Level Await.
+// In that case, it makes sense to set the exit code to a specific non-zero
+// value if the main code never finishes running.
+function handleProcessExit() {
+  process.exitCode ??= 13;
+}
+
+module.exports = {
+  handleProcessExit,
+};

lib/internal/modules/run_main.js

@@ -8,6 +8,9 @@ const CJSLoader = require('internal/modules/cjs/loader');
 const { Module, toRealPath, readPackageScope } = CJSLoader;
 const { getOptionValue } = require('internal/options');
 const path = require('path');
+const {
+  handleProcessExit,
+} = require('internal/modules/esm/handle_process_exit');
 
 function resolveMainPath(main) {
   // Note extension resolution for the main entry point can be deprecated in a
@@ -53,18 +56,11 @@ function runMainESM(mainPath) {
 }
 
 async function handleMainPromise(promise) {
-  // Handle a Promise from running code that potentially does Top-Level Await.
-  // In that case, it makes sense to set the exit code to a specific non-zero
-  // value if the main code never finishes running.
-  function handler() {
-    if (process.exitCode === undefined)
-      process.exitCode = 13;
-  }
-  process.on('exit', handler);
+  process.on('exit', handleProcessExit);
   try {
     return await promise;
   } finally {
-    process.off('exit', handler);
+    process.off('exit', handleProcessExit);
   }
 }
 

lib/internal/process/per_thread.js

@@ -48,6 +48,10 @@ const {
 } = require('internal/validators');
 const constants = internalBinding('constants').os.signals;
 
+const {
+  handleProcessExit,
+} = require('internal/modules/esm/handle_process_exit');
+
 const kInternal = Symbol('internal properties');
 
 function assert(x, msg) {
@@ -175,6 +179,8 @@ function wrapProcessMethods(binding) {
   memoryUsage.rss = rss;
 
   function exit(code) {
+    process.off('exit', handleProcessExit);
+
     if (code || code === 0)
       process.exitCode = code;
 

test/es-module/test-esm-tla-unfinished.mjs

@@ -80,3 +80,21 @@ import fixtures from '../common/fixtures.js';
   assert.deepStrictEqual([status, stdout], [1, '']);
   assert.match(stderr, /Error: Xyz/);
 }
+
+{
+  // Calling process.exit() in .mjs should return status 0
+  const { status, stdout, stderr } = child_process.spawnSync(
+    process.execPath,
+    [fixtures.path('es-modules/tla/process-exit.mjs')],
+    { encoding: 'utf8' });
+  assert.deepStrictEqual([status, stdout, stderr], [0, '', '']);
+}
+
+{
+  // Calling process.exit() in worker thread shouldn't influence main thread
+  const { status, stdout, stderr } = child_process.spawnSync(
+    process.execPath,
+    [fixtures.path('es-modules/tla/unresolved-with-worker-process-exit.mjs')],
+    { encoding: 'utf8' });
+  assert.deepStrictEqual([status, stdout, stderr], [13, '', '']);
+}

test/fixtures/es-modules/tla/process-exit.mjs

@@ -0,0 +1 @@
+process.exit();

test/fixtures/es-modules/tla/unresolved-with-worker-process-exit.mjs

@@ -0,0 +1,8 @@
+import { Worker, isMainThread } from 'worker_threads';
+
+if (isMainThread) {
+  new Worker(new URL(import.meta.url));
+  await new Promise(() => {});
+} else {
+  process.exit();
+}

test/parallel/test-bootstrap-modules.js

@@ -79,6 +79,7 @@ const expectedModules = new Set([
   'NativeModule internal/modules/esm/resolve',
   'NativeModule internal/modules/esm/initialize_import_meta',
   'NativeModule internal/modules/esm/translators',
+  'NativeModule internal/modules/esm/handle_process_exit',
   'NativeModule internal/process/esm_loader',
   'NativeModule internal/options',
   'NativeModule internal/perf/event_loop_delay',