feat: maintenance mode indicator for whitelisted ips

tests/Twig/MaintenanceModeTest.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Twig;
+
+use App\Twig\AppRuntime;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+class MaintenanceModeTest extends KernelTestCase
+{
+    private RequestStack $requestStack;
+    private AppRuntime $appRuntime;
+
+    protected function setUp(): void
+    {
+        self::bootKernel();
+
+        $this->requestStack = self::getContainer()->get(RequestStack::class);
+        $this->appRuntime = self::getContainer()->get(AppRuntime::class);
+    }
+
+    public function testMaintenanceModeIsReportedWhenTheListenerMarkedTheRequest(): void
+    {
+        $request = Request::create('/administrative/assignment');
+        $request->attributes->set('_maintenance_mode_allowed', true);
+        $this->requestStack->push($request);
+
+        self::assertTrue($this->appRuntime->isMaintenanceMode());
+    }
+
+    public function testNoMaintenanceModeOnAnUnmarkedRequest(): void
+    {
+        $this->requestStack->push(Request::create('/administrative/assignment'));
+
+        self::assertFalse($this->appRuntime->isMaintenanceMode());
+    }
+
+    /**
+     * Rendering outside a request, an email or a console command, must not blow up.
+     */
+    public function testNoMaintenanceModeWithoutARequest(): void
+    {
+        self::assertFalse($this->appRuntime->isMaintenanceMode());
+    }
+}