From 5f70054c484b794cf823051f3ca9e4caa73e667c Mon Sep 17 00:00:00 2001
From: Alan Agius <17563226+alan-agius4@users.noreply.github.com>
Date: Wed, 25 Feb 2026 11:39:31 +0000
Subject: [PATCH] fix(@angular/build): normalize `allowedHosts` in dev-server

This change ensures that allowed hosts starting with a dot (e.g. '.example.com') are converted to the wildcard format ('*.example.com') required by Angular SSR host validation. This aligns Vite's configuration style with Angular's internal validation logic.
---
 packages/angular/build/src/builders/dev-server/vite/index.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/angular/build/src/builders/dev-server/vite/index.ts b/packages/angular/build/src/builders/dev-server/vite/index.ts
index 009da8a40688..083008f17050 100644
--- a/packages/angular/build/src/builders/dev-server/vite/index.ts
+++ b/packages/angular/build/src/builders/dev-server/vite/index.ts
@@ -97,8 +97,10 @@ export async function* serveWithVite(
     browserOptions.ssr ||= true;
   }
 
+  // Vite allowedHost syntax doesn't allow `*.` but `.` acts as `*.`
+  // Angular SSR supports `*.`.
   const allowedHosts = Array.isArray(serverOptions.allowedHosts)
-    ? [...serverOptions.allowedHosts]
+    ? serverOptions.allowedHosts.map((host) => (host[0] === '.' ? '*' + host : host))
     : [];
 
   // Always allow the dev server host