fix: prevent stale dashboard chunks during startup

Author: Fridemn

dashboard/src/app/AppRouter.tsx

@@ -7,6 +7,7 @@ import { NotFoundPage } from '@/routes/NotFoundPage';
 import { BlankLayout } from '@/layouts/blank/BlankLayout';
 import { FullLayout } from '@/layouts/full/FullLayout';
 import { coreRouteModuleLoaders } from '@/app/coreRouteModules';
+import { RouteErrorPage } from '@/app/RouteErrorPage';
 
 const WelcomePage = lazy(() => import('@/routes/welcome/WelcomePage'));
 const AboutPage = lazy(() => import('@/routes/about/AboutPage'));
@@ -94,10 +95,12 @@ function routesForLayout(layout: RouteLayout) {
 const router = createHashRouter([
   {
     element: <BlankLayout />,
+    errorElement: <RouteErrorPage />,
     children: routesForLayout('protected-blank'),
   },
   {
     element: <FullLayout />,
+    errorElement: <RouteErrorPage />,
     children: [...routesForLayout('protected-full'), { path: '*', element: <NotFoundPage /> }],
   },
 ]);

dashboard/src/app/RouteErrorPage.tsx

@@ -0,0 +1,27 @@
+import { useRouteError } from 'react-router-dom';
+
+function errorMessage(error: unknown) {
+  if (error instanceof Error) return error.message;
+  if (typeof error === 'string') return error;
+  return 'An unexpected route error occurred.';
+}
+
+export function RouteErrorPage() {
+  const error = useRouteError();
+
+  const reloadFreshDocument = () => {
+    const url = new URL(window.location.href);
+    url.searchParams.set('_desktop_reload', Date.now().toString());
+    window.location.replace(url.toString());
+  };
+
+  return (
+    <main className="app-error" role="alert">
+      <h1>Dashboard failed to load</h1>
+      <p>{errorMessage(error)}</p>
+      <button type="button" onClick={reloadFreshDocument}>
+        Reload
+      </button>
+    </main>
+  );
+}

src-tauri/src/window/main_window.rs

@@ -1,4 +1,7 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
 use tauri::{AppHandle, Manager};
+use url::Url;
 
 pub fn show_main_window<F>(app_handle: &AppHandle, log: F)
 where
@@ -50,8 +53,13 @@ pub fn navigate_main_window_to_backend(
     app_handle: &AppHandle,
     backend_url: &str,
 ) -> Result<(), String> {
+    let cache_buster = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|duration| duration.as_millis())
+        .unwrap_or_default();
+    let navigation_url = backend_navigation_url(backend_url, cache_buster);
     let backend_url_json =
-        serde_json::to_string(backend_url).unwrap_or_else(|_| "\"/\"".to_string());
+        serde_json::to_string(&navigation_url).unwrap_or_else(|_| "\"/\"".to_string());
     let Some(window) = app_handle.get_webview_window("main") else {
         return Err("Main window is unavailable after backend startup.".to_string());
     };
@@ -61,3 +69,33 @@ pub fn navigate_main_window_to_backend(
         .eval(&js)
         .map_err(|error| format!("Failed to navigate to backend dashboard: {error}"))
 }
+
+fn backend_navigation_url(backend_url: &str, cache_buster: u128) -> String {
+    let Ok(mut url) = Url::parse(backend_url) else {
+        return backend_url.to_string();
+    };
+    url.query_pairs_mut()
+        .append_pair("_desktop_boot", &cache_buster.to_string());
+    url.into()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::backend_navigation_url;
+
+    #[test]
+    fn backend_navigation_adds_a_document_cache_buster() {
+        assert_eq!(
+            backend_navigation_url("http://127.0.0.1:6185", 1234),
+            "http://127.0.0.1:6185/?_desktop_boot=1234"
+        );
+    }
+
+    #[test]
+    fn backend_navigation_preserves_existing_query_parameters() {
+        assert_eq!(
+            backend_navigation_url("http://127.0.0.1:6185/?channel=stable", 1234),
+            "http://127.0.0.1:6185/?channel=stable&_desktop_boot=1234"
+        );
+    }
+}