From 4990269fa6c79ca9134a1ef8ac38ade0c626619c Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Wed, 19 Apr 2023 06:30:28 +0200
Subject: [PATCH] esm: propagate `process.exit` from the loader thread to the
 main thread

PR-URL: https://github.com/nodejs/node/pull/47548
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
---
 lib/internal/modules/esm/hooks.js        |  4 ++
 lib/internal/modules/esm/worker.js       | 13 +++++++
 test/es-module/test-esm-loader-hooks.mjs | 48 ++++++++++++++++++++++++
 3 files changed, 65 insertions(+)

diff --git a/lib/internal/modules/esm/hooks.js b/lib/internal/modules/esm/hooks.js
index e30ef7e895d1f2..8ab54bdbde9396 100644
--- a/lib/internal/modules/esm/hooks.js
+++ b/lib/internal/modules/esm/hooks.js
@@ -501,6 +501,7 @@ class HooksProxy {
       },
     });
     this.#worker.unref(); // ! Allows the process to eventually exit.
+    this.#worker.on('exit', process.exit);
   }
 
   #waitForWorker() {
@@ -510,6 +511,7 @@ class HooksProxy {
         debug('wait for signal from worker');
         AtomicsWait(this.#lock, WORKER_TO_MAIN_THREAD_NOTIFICATION, 0);
         const response = this.#worker.receiveMessageSync();
+        if (response.message.status === 'exit') { return; }
         const { preloadScripts } = this.#unwrapMessage(response);
         this.#executePreloadScripts(preloadScripts);
       }
@@ -590,6 +592,8 @@ class HooksProxy {
     debug('got sync response from worker', { method, args });
     if (response.message.status === 'never-settle') {
       process.exit(13);
+    } else if (response.message.status === 'exit') {
+      process.exit(response.message.body);
     }
     return this.#unwrapMessage(response);
   }
diff --git a/lib/internal/modules/esm/worker.js b/lib/internal/modules/esm/worker.js
index 8a1ef9add7060f..e343fbe03f1748 100644
--- a/lib/internal/modules/esm/worker.js
+++ b/lib/internal/modules/esm/worker.js
@@ -66,6 +66,19 @@ async function customizedModuleWorker(lock, syncCommPort, errorHandler) {
   let hooks, preloadScripts, initializationError;
   let hasInitializationError = false;
 
+  {
+    // If a custom hook is calling `process.exit`, we should wake up the main thread
+    // so it can detect the exit event.
+    const { exit } = process;
+    process.exit = function(code) {
+      syncCommPort.postMessage(wrapMessage('exit', code ?? process.exitCode));
+      AtomicsAdd(lock, WORKER_TO_MAIN_THREAD_NOTIFICATION, 1);
+      AtomicsNotify(lock, WORKER_TO_MAIN_THREAD_NOTIFICATION);
+      return ReflectApply(exit, this, arguments);
+    };
+  }
+
+
   try {
     initializeESM();
     const initResult = await initializeHooks();
diff --git a/test/es-module/test-esm-loader-hooks.mjs b/test/es-module/test-esm-loader-hooks.mjs
index 63cffdf40daf56..1ddb6f7167d312 100644
--- a/test/es-module/test-esm-loader-hooks.mjs
+++ b/test/es-module/test-esm-loader-hooks.mjs
@@ -143,4 +143,52 @@ describe('Loader hooks', { concurrency: true }, () => {
     assert.strictEqual(code, 0);
     assert.strictEqual(signal, null);
   });
+
+  it('should be fine to call `process.exit` from a custom async hook', async () => {
+    const { code, signal, stdout, stderr } = await spawnPromisified(execPath, [
+      '--no-warnings',
+      '--experimental-import-meta-resolve',
+      '--experimental-loader',
+      'data:text/javascript,export function load(a,b,next){if(a==="data:exit")process.exit(42);return next(a,b)}',
+      '--input-type=module',
+      '--eval',
+      'import "data:exit"',
+    ]);
+
+    assert.strictEqual(stderr, '');
+    assert.strictEqual(stdout, '');
+    assert.strictEqual(code, 42);
+    assert.strictEqual(signal, null);
+  });
+
+  it('should be fine to call `process.exit` from a custom sync hook', async () => {
+    const { code, signal, stdout, stderr } = await spawnPromisified(execPath, [
+      '--no-warnings',
+      '--experimental-import-meta-resolve',
+      '--experimental-loader',
+      'data:text/javascript,export function resolve(a,b,next){if(a==="exit:")process.exit(42);return next(a,b)}',
+      '--input-type=module',
+      '--eval',
+      'import "data:text/javascript,import.meta.resolve(%22exit:%22)"',
+    ]);
+
+    assert.strictEqual(stderr, '');
+    assert.strictEqual(stdout, '');
+    assert.strictEqual(code, 42);
+    assert.strictEqual(signal, null);
+  });
+
+  it('should be fine to call `process.exit` from the loader thread top-level', async () => {
+    const { code, signal, stdout, stderr } = await spawnPromisified(execPath, [
+      '--no-warnings',
+      '--experimental-loader',
+      'data:text/javascript,process.exit(42)',
+      fixtures.path('empty.js'),
+    ]);
+
+    assert.strictEqual(stderr, '');
+    assert.strictEqual(stdout, '');
+    assert.strictEqual(code, 42);
+    assert.strictEqual(signal, null);
+  });
 });