esm: propagate process.exit from the loader thread to the main thread

PR-URL: #47548
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Jacob Smith <jacob@frende.me>

Author: aduh95

lib/internal/modules/esm/hooks.js

@@ -504,6 +504,7 @@ class HooksProxy {
 },
 });
 this.#worker.unref();// ! Allows the process to eventually exit.
+this.#worker.on('exit',process.exit);
 }
 
  #waitForWorker(){
@@ -513,6 +514,7 @@ class HooksProxy {
 debug('wait for signal from worker');
 AtomicsWait(this.#lock,WORKER_TO_MAIN_THREAD_NOTIFICATION,0);
 constresponse=this.#worker.receiveMessageSync();
+if(response.message.status==='exit'){return;}
 const{ preloadScripts }=this.#unwrapMessage(response);
 this.#executePreloadScripts(preloadScripts);
 }
@@ -593,6 +595,8 @@ class HooksProxy {
 debug('got sync response from worker',{ method, args });
 if(response.message.status==='never-settle'){
 process.exit(kUnfinishedTopLevelAwait);
+}elseif(response.message.status==='exit'){
+process.exit(response.message.body);
 }
 returnthis.#unwrapMessage(response);
 }

lib/internal/modules/esm/worker.js

@@ -66,6 +66,19 @@ async function customizedModuleWorker(lock, syncCommPort, errorHandler) {
 lethooks,preloadScripts,initializationError;
 lethasInitializationError=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);
+returnReflectApply(exit,this,arguments);
+};
+}
+
+
 try{
 initializeESM();
 constinitResult=awaitinitializeHooks();

test/es-module/test-esm-loader-hooks.mjs

@@ -195,4 +195,52 @@ 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 }=awaitspawnPromisified(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 }=awaitspawnPromisified(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 }=awaitspawnPromisified(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);
+});
 });