Fix localhost redirect loops in proxy middleware using nextUrl.clone() and trustHost

auth.ts

@@ -3,6 +3,7 @@ import Credentials from "next-auth/providers/credentials";
 import { authenticateUser } from "@/lib/users";
 
 export const { handlers, signIn, signOut, auth } = NextAuth({
+  trustHost: true,
   providers: [
     Credentials({
       credentials: {

proxy.ts

@@ -7,11 +7,15 @@ export default auth((req) => {
   const isLoginPage = nextUrl.pathname === "/login";
 
   if (!isLoggedIn && !isLoginPage) {
-    return NextResponse.redirect(new URL("/login", req.url));
+    const url = nextUrl.clone();
+    url.pathname = "/login";
+    return NextResponse.redirect(url);
   }
 
   if (isLoggedIn && isLoginPage) {
-    return NextResponse.redirect(new URL("/dashboard", req.url));
+    const url = nextUrl.clone();
+    url.pathname = "/dashboard";
+    return NextResponse.redirect(url);
   }
 
   return NextResponse.next();