symfony
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md‎
Lines changed: 1 addition & 0 deletions b/‎src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php‎
Lines changed: 2 additions & 2 deletions b/‎src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php‎
Lines changed: 2 additions & 2 deletions
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php‎
Lines changed: 1 addition & 2 deletions b/‎src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php‎
Lines changed: 1 addition & 2 deletions
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php‎
Lines changed: 2 additions & 2 deletions b/‎src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php‎
Lines changed: 2 additions & 2 deletions
diff --git a/‎src/Symfony/Component/AssetMapper/CHANGELOG.md‎
Lines changed: 1 addition & 0 deletions b/‎src/Symfony/Component/AssetMapper/CHANGELOG.md‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎src/Symfony/Component/AssetMapper/ImportMap/ImportMapManager.php‎
Lines changed: 0 additions & 1 deletion b/‎src/Symfony/Component/AssetMapper/ImportMap/ImportMapManager.php‎
Lines changed: 0 additions & 1 deletion
diff --git a/‎src/Symfony/Component/AssetMapper/ImportMap/ImportMapRenderer.php‎
Lines changed: 21 additions & 3 deletions b/‎src/Symfony/Component/AssetMapper/ImportMap/ImportMapRenderer.php‎
Lines changed: 21 additions & 3 deletions
diff --git a/‎src/Symfony/Component/AssetMapper/Tests/ImportMap/ImportMapRendererTest.php‎
Lines changed: 31 additions & 3 deletions b/‎src/Symfony/Component/AssetMapper/Tests/ImportMap/ImportMapRendererTest.php‎
Lines changed: 31 additions & 3 deletions
@@ -31,6 +31,7 @@ CHANGELOG
  * Deprecate the `framework.asset_mapper.provider` config option
  * Add `--exclude` option to the `cache:pool:clear` command
  * Add parameters deprecations to the output of `debug:container` command
+ * Change `framework.asset_mapper.importmap_polyfill` from a URL to the name of an item in the importmap
 
 6.3
 ---
 
@@ -924,8 +924,8 @@ private function addAssetMapperSection(ArrayNodeDefinition $rootNode
10BC0
, callable $
                             ->defaultValue('%kernel.project_dir%/importmap.php')
                         ->end()
                         ->scalarNode('importmap_polyfill')
-                            ->info('URL of the ES Module Polyfill to use, false to disable. Defaults to using a CDN URL.')
-                            ->defaultValue(null)
+                            ->info('The importmap name that will be used to load the polyfill. Set to false to disable.')
+                            ->defaultValue('es-module-shims')
                         ->end()
                         ->arrayNode('importmap_script_attributes')
                             ->info('Key-value pair of attributes to add to script tags output for the importmap.')
 
@@ -33,7 +33,6 @@
 use Symfony\Component\Asset\PackageInterface;
 use Symfony\Component\AssetMapper\AssetMapper;
 use Symfony\Component\AssetMapper\Compiler\AssetCompilerInterface;
-use Symfony\Component\AssetMapper\ImportMap\ImportMapManager;
 use Symfony\Component\BrowserKit\AbstractBrowser;
 use Symfony\Component\Cache\Adapter\AdapterInterface;
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
@@ -1378,7 +1377,7 @@ private function registerAssetMapperConfiguration(array $config, ContainerBuilde
 
         $container
             ->getDefinition('asset_mapper.importmap.renderer')
-            ->replaceArgument(3, $config['importmap_polyfill'] ?? ImportMapManager::POLYFILL_URL)
+            ->replaceArgument(3, $config['importmap_polyfill'])
             ->replaceArgument(4, $config['importmap_script_attributes'])
         ;
     }
 
@@ -132,7 +132,7 @@ public function testAssetMapperCanBeEnabled()
             'missing_import_mode' => 'warn',
             'extensions' => [],
             'importmap_path' => '%kernel.project_dir%/importmap.php',
-            'importmap_polyfill' => null,
+            'importmap_polyfill' => 'es-module-shims',
             'vendor_dir' => '%kernel.project_dir%/assets/vendor',
             'importmap_script_attributes' => [],
         ];
@@ -668,7 +668,7 @@ protected static function getBundleDefaultConfig()
                 'missing_import_mode' => 'warn',
                 'extensions' => [],
                 'importmap_path' => '%kernel.project_dir%/importmap.php',
-                'importmap_polyfill' => null,
+                'importmap_polyfill' => 'es-module-shims',
                 'vendor_dir' => '%kernel.project_dir%/assets/vendor',
                 'importmap_script_attributes' => [],
             ],
 
@@ -17,6 +17,7 @@ CHANGELOG
  * Allow specifying packages to update for the `importmap:update` command
  * Add a `importmap:audit` command to check for security vulnerability advisories in dependencies
  * Add a `importmap:outdated` command to check for outdated packages
+ * Change the polyfill used for the importmap renderer from a URL to an entry in the importmap
 
 6.3
 ---
 
@@ -24,7 +24,6 @@
  */
 class ImportMapManager
 {
-    public const POLYFILL_URL = 'https://ga.jspm.io/npm:es-module-shims@1.7.2/dist/es-module-shims.js';
     public const IMPORT_MAP_CACHE_FILENAME = 'importmap.json';
     public const ENTRYPOINT_CACHE_FILENAME_PATTERN = 'entrypoint.%s.json';
 
 
@@ -27,11 +27,13 @@
  */
 class ImportMapRenderer
 {
+    private const DEFAULT_ES_MODULE_SHIMS_POLYFILL_URL = 'https://ga.jspm.io/npm:es-module-shims@1.8.0/dist/es-module-shims.js';
+
     public function __construct(
         private readonly ImportMapManager $importMapManager,
         private readonly ?Packages $assetPackages = null,
         private readonly string $charset = 'UTF-8',
-        private readonly string|false $polyfillUrl = ImportMapManager::POLYFILL_URL,
+        private readonly string|false $polyfillImportName = false,
         private readonly array $scriptAttributes = [],
         private readonly ?RequestStack $requestStack = null,
     ) {
@@ -45,6 +47,7 @@ public function render(string|array $entryPoint, array $attributes = []): string
         $importMap = [];
         $modulePreloads = [];
         $cssLinks = [];
+        $polyFillPath = null;
         foreach ($importMapData as $importName => $data) {
             $path = $data['path'];
 
@@ -53,6 +56,12 @@ public function render(string|array $entryPoint, array $attributes = []): string
                 $path = $this->assetPackages->getUrl(ltrim($path, '/'));
             }
 
+            // if this represents the polyfill, hide it from the import map
+            if ($importName === $this->polyfillImportName) {
+                $polyFillPath = $path;
+                continue;
+            }
+
             $preload = $data['preload'] ?? false;
             if ('css' !== $data['type']) {
                 $importMap[$importName] = $path;
@@ -87,8 +96,17 @@ public function render(string|array $entryPoint, array $attributes = []): string
             </script>
             HTML;
 
-        if ($this->polyfillUrl) {
-            $url = $this->escapeAttributeValue($this->polyfillUrl);
+        if (false !== $this->polyfillImportName && null === $polyFillPath) {
+            if ('es-module-shims' !== $this->polyfillImportName) {
+                throw new \InvalidArgumentException(sprintf('The JavaScript module polyfill was not found in your import map. Either disable the polyfill or run "php bin/console importmap:require "%s"" to install it.', $this->polyfillImportName));
+            }
+
+            // a fallback for the default polyfill in case it's not in the importmap
+            $polyFillPath = self::DEFAULT_ES_MODULE_SHIMS_POLYFILL_URL;
+        }
+
+        if ($polyFillPath) {
+            $url = $this->escapeAttributeValue($polyFillPath);
 
             $output .= <<<HTML
 
 
@@ -50,6 +50,10 @@ public function testBasicRender()
                     'path' => 'https://cdn.example.com/assets/remote-d1g35t.js',
                     'type' => 'js',
                 ],
+                'es-module-shim' => [
+                    'path' => 'https://ga.jspm.io/npm:es-module-shims',
+                    'type' => 'js',
+                ],
             ]);
 
         $assetPackages = $this->createMock(Packages::class);
@@ -64,11 +68,14 @@ public function testBasicRender()
                 return '/subdirectory/'.$path;
             });
 
-        $renderer = new ImportMapRenderer($importMapManager, $assetPackages);
+        $renderer = new ImportMapRenderer($importMapManager, $assetPackages, polyfillImportName: 'es-module-shim');
         $html = $renderer->render(['app']);
 
         $this->assertStringContainsString('<script type="importmap">', $html);
-        $this->assertStringContainsString('https://ga.jspm.io/npm:es-module-shims', $html);
+        // polyfill is rendered as a normal script tag
+        $this->assertStringContainsString('<script async src="https://ga.jspm.io/npm:es-module-shims"></script>', $html);
+        // and is hidden from the import map
+        $this->assertStringNotContainsString('"es-module-shim"', $html);
         $this->assertStringContainsString('import \'app\';', $html);
 
         // preloaded js file
@@ -93,9 +100,26 @@ public function testNoPolyfill()
         $this->assertStringNotContainsString('https://ga.jspm.io/npm:es-module-shims', $renderer->render([]));
     }
 
+    public function testDefaultPolyfillUsedIfNotInImportmap()
+    {
+        $importMapManager = $this->createMock(ImportMapManager::class);
+        $importMapManager->expects($this->once())
+            ->method('getImportMapData')
+            ->with(['app'])
+            ->willReturn([]);
+
+        $renderer = new ImportMapRenderer(
+            $importMapManager,
+            $this->createMock(Packages::class),
+            polyfillImportName: 'es-module-shims',
+        );
+        $html = $renderer->render(['app']);
+        $this->assertStringContainsString('<script async src="https://ga.jspm.io/npm:es-module-shims@', $html);
+    }
+
     public function testCustomScriptAttributes()
     {
-        $renderer = new ImportMapRenderer($this->createBasicImportMapManager(), null, 'UTF-8', 'https://polyfillUrl.example', [
+        $renderer = new ImportMapRenderer($this->createBasicImportMapManager(), null, 'UTF-8', 'es-module-shims', [
             'something' => true,
             'data-turbo-track' => 'reload',
         ]);
@@ -128,6 +152,10 @@ private function createBasicImportMapManager(): ImportMapManager
                     'path' => 'app.js',
                     'type' => 'js',
                 ],
+                'es-module-shims' => [
+                    'path' => 'https://polyfillUrl.example',
+                    'type' => 'js',
+                ],
             ])
         ;