From 1b387700d39aa00210a7deace0bee40e66f3c175 Mon Sep 17 00:00:00 2001
From: robot <robot@hermes.local>
Date: Sun, 9 Aug 2026 01:13:50 +0000
Subject: [PATCH] fix(ssr): prefer index.csr.html over prerendered index.html
 for CSR users
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The browserIndexPath() function was resolving index.html first, which is
the prerendered output with stale build-time content baked into <app-root>.
Even with window.__STATION_CONFIG injection, the prerendered innerHTML
still shows old content on the first paint until Angular re-renders.

By preferring index.csr.html (the pure CSR shell with empty <app-root>),
regular users get a clean first paint — no stale prerendered DOM to flash.
---
 server.ts | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/server.ts b/server.ts
index 2d5c3f3..6bfa6e3 100644
--- a/server.ts
+++ b/server.ts
@@ -72,7 +72,17 @@ const COLOR_MAP: ReadonlyArray<{ field: keyof StationConfig; prop: string }> = [
 ];
 
 /**
- * Resolve the static browser index.html path.
+ * Resolve the static CSR shell path (index.csr.html).
+ *
+ * IMPORTANT: We MUST prefer index.csr.html over index.html.
+ * The Angular build with prerender config produces both:
+ * - index.html: prerendered at build time with stale DEFAULT_CONFIG baked in
+ * - index.csr.html: pure CSR shell with empty <app-root> — Angular hydrates client-side
+ *
+ * Serving index.html to regular users causes the flash: the prerendered DOM
+ * shows stale build-time content until Angular re-renders with fresh data.
+ * Even with window.__STATION_CONFIG injection, the prerendered innerHTML inside
+ * <app-root> still shows old content on the first paint.
  *
  * Production (Docker): browser files are copied to /usr/share/nginx/html/
  * Local dev (ng build): browser files live in dist/radio-station/browser/
@@ -80,9 +90,11 @@ const COLOR_MAP: ReadonlyArray<{ field: keyof StationConfig; prop: string }> = [
  */
 function browserIndexPath(): string {
   // Production path — Dockerfile copies browser output here
+  // CSR shell first — avoid prerendered index.html with stale content
   const productionPaths = [
-    '/usr/share/nginx/html/index.html',
     '/usr/share/nginx/html/index.csr.html',
+    '/usr/share/nginx/html/index.html',
+    '/var/www/html/index.csr.html',
     '/var/www/html/index.html',
   ];