url: return backslashes from fileURLToPath on win

PR-URL: https://github.com/nodejs/node/pull/25349
Fixes: https://github.com/nodejs/node/issues/25265
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/internal/url.js b/lib/internal/url.js
index 45ed236511..6ad7122b86 100644
--- a/lib/internal/url.js
+++ b/lib/internal/url.js
@@ -1275,6 +1275,8 @@ function urlToOptions(url) {
   return options;
 }
 
+const forwardSlashRegEx = /\//g;
+
 function getPathFromURLWin32(url) {
   var hostname = url.hostname;
   var pathname = url.pathname;
@@ -1289,6 +1291,7 @@ function getPathFromURLWin32(url) {
       }
     }
   }
+  pathname = pathname.replace(forwardSlashRegEx, '\\');
   pathname = decodeURIComponent(pathname);
   if (hostname !== '') {
     // If hostname is set, then we have a UNC path
@@ -1297,7 +1300,7 @@ function getPathFromURLWin32(url) {
     // about percent encoding because the URL parser will have
     // already taken care of that for us. Note that this only
     // causes IDNs with an appropriate `xn--` prefix to be decoded.
-    return `//${domainToUnicode(hostname)}${pathname}`;
+    return `\\\\${domainToUnicode(hostname)}${pathname}`;
   } else {
     // Otherwise, it's a local path that requires a drive letter
     var letter = pathname.codePointAt(1) | 0x20;