module: experimental modules runMain separation

PR-URL: #21350
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

Author: guybedford

lib/internal/modules/cjs/loader.js

@@ -504,19 +504,6 @@ Module._load = function(request, parent, isMain) {
 debug('Module._load REQUEST %s parent: %s',request,parent.id);
 }
 
-if(experimentalModules&&isMain){
-if(asyncESM===undefined)lazyLoadESM();
-asyncESM.loaderPromise.then((loader)=>{
-returnloader.import(getURLFromFilePath(request).pathname);
-})
-.catch((e)=>{
-decorateErrorStack(e);
-console.error(e);
-process.exit(1);
-});
-return;
-}
-
 varfilename=Module._resolveFilename(request,parent,isMain);
 
 varcachedModule=Module._cache[filename];
@@ -741,7 +728,19 @@ if (experimentalModules) {
 // bootstrap main module.
 Module.runMain=function(){
 // Load the main module--the command line argument.
-Module._load(process.argv[1],null,true);
+if(experimentalModules){
+if(asyncESM===undefined)lazyLoadESM();
+asyncESM.loaderPromise.then((loader)=>{
+returnloader.import(getURLFromFilePath(process.argv[1]).pathname);
+})
+.catch((e)=>{
+decorateErrorStack(e);
+console.error(e);
+process.exit(1);
+});
+}else{
+Module._load(process.argv[1],null,true);
+}
 // Handle any nextTicks added in the first tick of the program
 process._tickCallback();
 };

test/es-module/test-esm-cjs-main.js

@@ -1,6 +1,27 @@
-// Flags: --experimental-modules
 'use strict';
-require('../common');
+
+constcommon=require('../common');
+constfixtures=require('../common/fixtures');
+const{ spawn }=require('child_process');
 constassert=require('assert');
-exports.asdf='asdf';
-assert.strictEqual(require.main.exports.asdf,'asdf');
+
+constentry=fixtures.path('/es-modules/cjs.js');
+
+constchild=spawn(process.execPath,['--experimental-modules',entry]);
+letexperimentalWarning=false;
+letvalidatedExecution=false;
+child.stderr.on('data',(data)=>{
+if(!experimentalWarning){
+experimentalWarning=true;
+return;
+}
+thrownewError(data.toString());
+});
+child.stdout.on('data',(data)=>{
+assert.strictEqual(data.toString(),'executed\n');
+validatedExecution=true;
+});
+child.on('close',common.mustCall((code,stdout)=>{
+assert.strictEqual(validatedExecution,true);
+assert.strictEqual(code,0);
+}));

test/es-module/test-esm-error-cache.js

@@ -7,7 +7,7 @@ const assert = require('assert');
 
 common.crashOnUnhandledRejection();
 
-constfile='../../fixtures/syntax/bad_syntax.js';
+constfile='../fixtures/syntax/bad_syntax.js';
 
 leterror;
 (async()=>{

test/fixtures/es-modules/cjs.js

@@ -0,0 +1,5 @@
+'use strict';
+
+// test we can use commonjs require
+require('path');
+console.log('executed');