src: fix ESM path resolution on Windows

Windows has some reserved file names such as "con", "prn",
"nul", etc. Such files can be accessed only if the path is
prefixed with "\\.\"
PR-URL: #29574
Reviewed-By: Guy Bedford <guybedford@gmail.com>

Author: Hakerh400

src/module_wrap.cc

@@ -488,7 +488,12 @@ enum DescriptorType {
 // Nothing for the "null" cache entries.
 inline Maybe<uv_file> OpenDescriptor(const std::string& path) {
 uv_fs_t fs_req;
+#ifdef _WIN32
+ std::string pth = "\\\\.\\" + path;
+ uv_file fd = uv_fs_open(nullptr, &fs_req, pth.c_str(), O_RDONLY, 0, nullptr);
+#else
  uv_file fd = uv_fs_open(nullptr, &fs_req, path.c_str(), O_RDONLY, 0, nullptr);
+#endif
 uv_fs_req_cleanup(&fs_req);
 if (fd < 0) return Nothing<uv_file>();
 returnJust(fd);

test/es-module/test-esm-windows.js

@@ -0,0 +1,49 @@
+'use strict';
+
+// Flags: --experimental-modules
+// This test ensures that JavaScript file that includes
+// a reserved Windows word can be loaded as ESM module
+
+constcommon=require('../common');
+consttmpdir=require('../common/tmpdir');
+constassert=require('assert');
+constfs=require('fs').promises;
+constpath=require('path');
+
+constimp=(file)=>{
+returnimport(path.relative(__dirname,file).replace(/\\/g,'/'));
+};
+
+(async()=>{
+consttmp=tmpdir.path;
+awaitfs.mkdir(tmp).catch(()=>{});
+constrel=(file)=>path.join(tmp,file);
+
+{// Load a single script
+constfile=rel('con.mjs');
+awaitfs.writeFile(file,'export default "ok"');
+assert.strictEqual((awaitimp(file)).default,'ok');
+awaitfs.unlink(file);
+}
+
+{// Load a module
+constentry=rel('entry.mjs');
+constnmDir=rel('node_modules');
+constmDir=rel('node_modules/con');
+constpkg=rel('node_modules/con/package.json');
+constscript=rel('node_modules/con/index.mjs');
+
+awaitfs.writeFile(entry,'export {default} from "con"');
+awaitfs.mkdir(nmDir);
+awaitfs.mkdir(mDir);
+awaitfs.writeFile(pkg,'{"main":"index.mjs"}');
+awaitfs.writeFile(script,'export default "ok"');
+
+assert.strictEqual((awaitimp(entry)).default,'ok');
+awaitfs.unlink(script);
+awaitfs.unlink(pkg);
+awaitfs.rmdir(mDir);
+awaitfs.rmdir(nmDir);
+awaitfs.unlink(entry);
+}
+})().then(common.mustCall());