feat: reload the page with a flash when an htmx request fails

tests/Security/LoginEntryPointTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Security;
+
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+
+class LoginEntryPointTest extends WebTestCase
+{
+    /**
+     * A plain 302 would be followed invisibly and the login page swapped into the click's target.
+     *
+     * The status stays 403 -- Symfony's firewall keeps the access-denied status on this path --
+     * and that is fine: htmx 2.0.10 acts on HX-Redirect before it looks at the status at all
+     * (handleAjaxResponse), so it navigates rather than raising htmx:responseError.
+     */
+    public function testAnExpiredSessionOnAnHtmxRequestNavigatesToTheLoginPage(): void
+    {
+        $client = self::createClient();
+
+        $client->request('GET', '/book/desk', server: ['HTTP_HX-Request' => 'true']);
+
+        self::assertSame('/login', $client->getResponse()->headers->get('HX-Redirect'));
+    }
+
+    public function testAnExpiredSessionOnAnOrdinaryRequestStillRedirects(): void
+    {
+        $client = self::createClient();
+
+        $client->request('GET', '/book/desk');
+
+        self::assertResponseRedirects('/login');
+    }
+}