From 2af6157265c16a1852df491c9436c21dc5ce339f Mon Sep 17 00:00:00 2001
From: lebaudantoine <lebaud.antoine131@gmail.com>
Date: Wed, 12 Aug 2026 19:36:52 +0200
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8(frontend)=20recover=20from=20stale=20?=
 =?UTF-8?q?lazy-loaded=20chunks=20after=20a=20deploy?=
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Route components are code-split with content-hashed filenames. A
user who loaded the app before a deployment (typically someone
sitting in a call) still holds an `index.html` referencing old chunk
names. When they navigate after the deploy — e.g. to `/feedback` on
leaving a room — the old chunk is gone and the dynamic import fails
with "TypeError: error loading dynamically imported module".

Reload the page on that failure to fetch a fresh `index.html` with
the current hashes, which transparently fixes the stale-deploy case.

Guard against infinite reload loops with a `RELOAD_COOLDOWN_MS`: if
the import fails again right after a reload, the cause is not a
stale deploy (ad blocker, proxy, outage) and reloading further would
loop forever. In that case, let the error propagate so it reaches
monitoring.

Inspired by https://vite.dev/guide/build#load-error-handling
---
 CHANGELOG.md              |  4 ++++
 src/frontend/src/main.tsx | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 404e8084..3caf157b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+- ✨(frontend) recover from stale lazy-loaded chunks after a deploy
+
 ## [1.26.0] - 2026-08-12
 
 ### Added
diff --git a/src/frontend/src/main.tsx b/src/frontend/src/main.tsx
index ed319314..75661d2d 100644
--- a/src/frontend/src/main.tsx
+++ b/src/frontend/src/main.tsx
@@ -2,6 +2,26 @@ import React from 'react'
 import ReactDOM from 'react-dom/client'
 import App from './App.tsx'
 
+const CHUNK_RELOAD_KEY = 'vite-preload-error-reload-at'
+const RELOAD_COOLDOWN_MS = 30_000
+
+window.addEventListener('vite:preloadError', (event) => {
+  try {
+    const lastReloadAt = Number(sessionStorage.getItem(CHUNK_RELOAD_KEY)) || 0
+    if (Date.now() - lastReloadAt <= RELOAD_COOLDOWN_MS) {
+      // Recent reload didn't help: not a stale deploy, surface the error.
+      return
+    }
+    sessionStorage.setItem(CHUNK_RELOAD_KEY, String(Date.now()))
+  } catch {
+    // Without sessionStorage we cannot guard against a reload loop:
+    // don't auto-reload, let the error propagate.
+    return
+  }
+  event.preventDefault()
+  window.location.reload()
+})
+
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <App />