lib: simplify IPv6 checks in isLoopback()

pckrishnadas88 · targos · commit 9a12f71ad933 · 2025-08-21T19:00:57.000+02:00
The checks for '[::1]' and '[0:0:0:0:0:0:0:1]' in isLoopback were using startsWith, which is unnecessary as these are canonical loopback addresses with no valid prefixes. Switching to strict equality improves clarity and improves performance. PR-URL: #59375 Reviewed-By: Tim Perry <pimterry@gmail.com> Reviewed-By: theanarkh <theratliter@gmail.com> Reviewed-By: Ethan Arrowood <ethan@arrowood.dev> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Stefan Stojanovic <stefan.stojanovic@janeasystems.com>
diff --git a/lib/internal/net.js b/lib/internal/net.js
@@ -93,8 +93,8 @@ function isLoopback(host) {
   return (
     hostLower === 'localhost' ||
     hostLower.startsWith('127.') ||
-    hostLower.startsWith('[::1]') ||
-    hostLower.startsWith('[0:0:0:0:0:0:0:1]')
+    hostLower === '[::1]' ||
+    hostLower === '[0:0:0:0:0:0:0:1]'
   );
 }
 
