module: fix --preserve-symlinks-main

Fixes resolving main module when the `argv[1]` was pointing to a symlink without its file extension. PR-URL: #51312Fixes: #41000 Reviewed-By: Antoine du Hamel <[email protected]>

Author: per4uk

lib/internal/modules/cjs/loader.js

@@ -470,15 +470,15 @@ function tryPackage(requestPath, exts, isMain, originalPath){
 }
 
 /**
- * Check if the file exists and is not a directory if using `--preserve-symlinks` and `isMain` is false, keep symlinks
- * intact, otherwise resolve to the absolute realpath.
+ * Check if the file exists and is not a directory if using `--preserve-symlinks` and `isMain` is false or
+ * `--preserve-symlinks-main` and `isMain` is true , keep symlinks intact, otherwise resolve to the absolute realpath.
  * @param{string} requestPath The path to the file to load.
  * @param{boolean} isMain Whether the file is the main module.
  */
 functiontryFile(requestPath,isMain){
 constrc=_stat(requestPath);
 if(rc!==0){return;}
-if(getOptionValue('--preserve-symlinks')&&!isMain){
+if(getOptionValue(isMain ? '--preserve-symlinks-main' : '--preserve-symlinks')){
 returnpath.resolve(requestPath);
 }
 returntoRealPath(requestPath);

test/es-module/test-esm-preserve-symlinks-main.js

@@ -1,20 +1,27 @@
 'use strict';
 
-constcommon=require('../common');
-const{ spawn }=require('child_process');
-constassert=require('assert');
-constpath=require('path');
-constfs=require('fs');
-
+const{ spawnPromisified, skip }=require('../common');
 consttmpdir=require('../common/tmpdir');
+
+// Invoke the main file via a symlink. In this case --preserve-symlinks-main
+// dictates that it'll resolve relative imports in the main file relative to
+// the symlink, and not relative to the symlink target; the file structure set
+// up below requires this to not crash when loading ./submodule_link.js
+
+constassert=require('node:assert');
+constfs=require('node:fs');
+constpath=require('node:path');
+const{ execPath }=require('node:process');
+const{ describe, it }=require('node:test');
+
 tmpdir.refresh();
 consttmpDir=tmpdir.path;
 
 fs.mkdirSync(path.join(tmpDir,'nested'));
 fs.mkdirSync(path.join(tmpDir,'nested2'));
 
 constentry=path.join(tmpDir,'nested','entry.js');
-constentry_link_absolute_path=path.join(tmpDir,'link.js');
+constentry_link_absolute_path=path.join(tmpDir,'index.js');
 constsubmodule=path.join(tmpDir,'nested2','submodule.js');
 constsubmodule_link_absolute_path=path.join(tmpDir,'submodule_link.js');
 
@@ -31,27 +38,39 @@ try{
 fs.symlinkSync(submodule,submodule_link_absolute_path);
 }catch(err){
 if(err.code!=='EPERM')throwerr;
-common.skip('insufficient privileges for symlinks');
+skip('insufficient privileges for symlinks');
 }
 
-functiondoTest(flags,done){
-// Invoke the main file via a symlink. In this case --preserve-symlinks-main
-// dictates that it'll resolve relative imports in the main file relative to
-// the symlink, and not relative to the symlink target; the file structure set
-// up above requires this to not crash when loading ./submodule_link.js
-spawn(process.execPath,[
-'--preserve-symlinks',
-'--preserve-symlinks-main',
-entry_link_absolute_path,
-],{stdio: 'inherit'})
-.on('exit',(code)=>{
-assert.strictEqual(code,0);
-done();
-});
-}
+describe('Invoke the main file via a symlink.',{concurrency: true},()=>{
+it('should resolve relative imports in the main file',async()=>{
+const{ code }=awaitspawnPromisified(execPath,[
+'--preserve-symlinks',
+'--preserve-symlinks-main',
+entry_link_absolute_path,
+]);
+
+assert.strictEqual(code,0);
+});
+
+it('should resolve relative imports in the main file when file extension is omitted',async()=>{
+constentry_link_absolute_path_without_ext=path.join(tmpDir,'index');
+
+const{ code }=awaitspawnPromisified(execPath,[
+'--preserve-symlinks',
+'--preserve-symlinks-main',
+entry_link_absolute_path_without_ext,
+]);
+
+assert.strictEqual(code,0);
+});
+
+it('should resolve relative imports in the main file when filename(index.js) is omitted',async()=>{
+const{ code }=awaitspawnPromisified(execPath,[
+'--preserve-symlinks',
+'--preserve-symlinks-main',
+tmpDir,
+]);
 
-// First test the commonjs module loader
-doTest([],()=>{
-// Now test the new loader
-doTest([],()=>{});
+assert.strictEqual(code,0);
+});
 });