[4.x] Show warning when manifest is outdated

resources/views/layout.blade.php

@@ -92,6 +92,12 @@
             </div>
 
             <div class="col-10">
+                @if (! $assetsAreCurrent)
+                    <div class="alert alert-warning">
+                        The published Horizon assets are not up-to-date with the installed version. To update, run:<br/><code>php artisan horizon:publish</code>
+                    </div>
+                @endif
+
                 <router-view></router-view>
             </div>
         </div>

src/Horizon.php

@@ -4,6 +4,8 @@
 
 use Closure;
 use Exception;
+use Illuminate\Support\Facades\File;
+use RuntimeException;
 
 class Horizon
 {
@@ -169,4 +171,22 @@ public static function routeSmsNotificationsTo($number)
 
         return new static;
     }
+
+    /**
+     * Determine if Horizon's published assets are up-to-date.
+     *
+     * @return bool
+     *
+     * @throws \RuntimeException
+     */
+    public static function assetsAreCurrent()
+    {
+        $publishedPath = public_path('vendor/horizon/mix-manifest.json');
+
+        if (! File::exists($publishedPath)) {
+            throw new RuntimeException('Horizon assets are not published. Please run: php artisan horizon:publish');
+        }
+
+        return File::get($publishedPath) === File::get(__DIR__.'/../public/mix-manifest.json');
+    }
 }

src/Http/Controllers/HomeController.php

@@ -9,13 +9,14 @@ class HomeController extends Controller
     /**
      * Single page application catch-all route.
      *
-     * @return \Illuminate\Http\Response
+     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
      */
     public function index()
     {
         return view('horizon::layout', [
             'cssFile' => Horizon::$useDarkTheme ? 'app-dark.css' : 'app.css',
             'horizonScriptVariables' => Horizon::scriptVariables(),
+            'assetsAreCurrent' => Horizon::assetsAreCurrent(),
         ]);
     }
 }