unify generating webpack asset url

app/Services/Webpack.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Services;
 
 use Illuminate\Filesystem\Filesystem;
+use Illuminate\Routing\UrlGenerator;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Str;
 
@@ -15,14 +16,20 @@ class Webpack
     /** @var Option */
     protected $options;
 
-    public function __construct(Filesystem $filesystem, Option $options)
-    {
+    protected $urlGenerator;
+
+    public function __construct(
+        Filesystem $filesystem,
+        Option $options,
+        UrlGenerator $urlGenerator
+    ) {
         $path = public_path('app/manifest.json');
         if ($filesystem->exists($path)) {
             $this->manifest = json_decode($filesystem->get($path), true);
         }
 
         $this->options = $options;
+        $this->urlGenerator = $urlGenerator;
     }
 
     public function __get(string $path)
@@ -33,14 +40,14 @@ class Webpack
     public function url(string $path): string
     {
         if (Str::startsWith(config('app.asset.env'), 'dev')) {
-            $base = config('app.asset.url');
+            $root = config('app.asset.url').':8080';
 
-            return "$base:8080/$path";
+            return $this->urlGenerator->assetFrom($root, $path);
         } else {
             $path = $this->$path;
             $cdn = $this->options->get('cdn_address');
 
-            return $cdn ? "$cdn/app/$path" : url("/app/$path");
+            return $this->urlGenerator->assetFrom($cdn, "/app/$path");
         }
     }
 }

tests/ServicesTest/WebpackTest.php

@@ -43,7 +43,7 @@ class WebpackTest extends TestCase
 
         $this->app->forgetInstance(Webpack::class);
         $webpack = $this->app->make(Webpack::class);
-        $this->assertEquals('http://localhost/app/b', $webpack->url('a'));
+        $this->assertEquals('/app/b', $webpack->url('a'));
 
         $this->mock(\App\Services\Option::class, function ($mock) {
             $mock->shouldReceive('get')