loader: fix esm resolve for symlink file

Fix: #42195
PR-URL: #42197Fixes: #42195
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>

Author: meixg

lib/internal/modules/esm/resolve.js

@@ -374,18 +374,24 @@ function finalizeResolution(resolved, base, preserveSymlinks) {
 resolved.pathname,'must not include encoded "/" or "\\" characters',
 fileURLToPath(base));
 
-constpath=fileURLToPath(resolved);
+letpath=fileURLToPath(resolved);
 if(getOptionValue('--experimental-specifier-resolution')==='node'){
 letfile=resolveExtensionsWithTryExactName(resolved);
-if(file!==undefined)returnfile;
-if(!StringPrototypeEndsWith(path,'/')){
-file=resolveDirectoryEntry(newURL(`${resolved}/`));
-if(file!==undefined)returnfile;
-}else{
-returnresolveDirectoryEntry(resolved)||resolved;
+
+// Directory
+if(file===undefined){
+file=StringPrototypeEndsWith(path,'/') ?
+(resolveDirectoryEntry(resolved)||resolved) : resolveDirectoryEntry(newURL(`${resolved}/`));
+
+if(file===resolved)returnfile;
+
+if(file===undefined){
+thrownewERR_MODULE_NOT_FOUND(
+resolved.pathname,fileURLToPath(base),'module');
+}
 }
-thrownewERR_MODULE_NOT_FOUND(
-resolved.pathname,fileURLToPath(base),'module');
+
+path=file;
 }
 
 conststats=tryStatSync(StringPrototypeEndsWith(path,'/') ?

test/es-module/test-esm-specifiers-symlink.mjs

@@ -0,0 +1,40 @@
+import*ascommonfrom'../common/index.mjs';
+importpathfrom'path';
+importfsfrom'fs/promises';
+importtmpdirfrom'../common/tmpdir.js';
+import{spawn}from'child_process';
+importassertfrom'assert';
+
+tmpdir.refresh();
+consttmpDir=tmpdir.path;
+
+// Create the following file structure:
+// ├── index.mjs
+// ├── subfolder
+// │ ├── index.mjs
+// │ └── node_modules
+// │ └── package-a
+// │ └── index.mjs
+// └── symlink.mjs -> ./subfolder/index.mjs
+constentry=path.join(tmpDir,'index.mjs');
+constsymlink=path.join(tmpDir,'symlink.mjs');
+constreal=path.join(tmpDir,'subfolder','index.mjs');
+constpackageDir=path.join(tmpDir,'subfolder','node_modules','package-a');
+constpackageEntry=path.join(packageDir,'index.mjs');
+try{
+awaitfs.symlink(real,symlink);
+}catch(err){
+if(err.code!=='EPERM')throwerr;
+common.skip('insufficient privileges for symlinks');
+}
+awaitfs.mkdir(packageDir,{recursive: true});
+awaitPromise.all([
+fs.writeFile(entry,'import "./symlink.mjs";'),
+fs.writeFile(real,'export { a } from "package-a/index.mjs"'),
+fs.writeFile(packageEntry,'export const a = 1;'),
+]);
+
+spawn(process.execPath,['--experimental-specifier-resolution=node',entry],
+{stdio: 'inherit'}).on('exit',common.mustCall((code)=>{
+assert.strictEqual(code,0);
+}));