module: process.exit() should result in exit code 0

lib/internal/modules/esm/handle_process_exit.js

@@ -0,0 +1,10 @@
+'use strict';
+
+function handleProcessExit() {
+  if (process.exitCode === undefined)
+    process.exitCode = 13; 
+}
+
+module.exports = {
+  handleProcessExit,
+}

lib/internal/modules/run_main.js

@@ -8,6 +8,7 @@ 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
@@ -56,15 +57,11 @@ 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 +48,8 @@ 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 +177,8 @@ 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 +80,22 @@ 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 .mjs should return status 0
+  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 +1,10 @@
+import { Worker } from 'worker_threads';
+
+// Do not use isMainThread so that this test itself can be run inside a Worker.
+if (!process.env.HAS_STARTED_WORKER) {
+  process.env.HAS_STARTED_WORKER = 1;
+  new Worker(import.meta.url.slice('file://'.length));
+  await new Promise(() => {});
+} else {
+  process.exit()
+}