Issue #3269154 by longwave: Remove BC layers from the theme system

core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php

@@ -108,7 +108,7 @@ class HtmlRenderer implements MainContentRendererInterface {
    * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
    *   The theme manager.
    */
-  public function __construct(TitleResolverInterface $title_resolver, PluginManagerInterface $display_variant_manager, EventDispatcherInterface $event_dispatcher, ModuleHandlerInterface $module_handler, RendererInterface $renderer, RenderCacheInterface $render_cache, array $renderer_config, ThemeManagerInterface $theme_manager = NULL) {
+  public function __construct(TitleResolverInterface $title_resolver, PluginManagerInterface $display_variant_manager, EventDispatcherInterface $event_dispatcher, ModuleHandlerInterface $module_handler, RendererInterface $renderer, RenderCacheInterface $render_cache, array $renderer_config, ThemeManagerInterface $theme_manager) {
     $this->titleResolver = $title_resolver;
     $this->displayVariantManager = $display_variant_manager;
     $this->eventDispatcher = $event_dispatcher;
@@ -116,10 +116,6 @@ class HtmlRenderer implements MainContentRendererInterface {
     $this->renderer = $renderer;
     $this->renderCache = $render_cache;
     $this->rendererConfig = $renderer_config;
-    if ($theme_manager === NULL) {
-      @trigger_error('Calling ' . __METHOD__ . ' without the $theme_manager argument is deprecated in drupal:9.1.0 and will be required in drupal:10.0.0. See https://www.drupal.org/node/3159762', E_USER_DEPRECATED);
-      $theme_manager = \Drupal::service('theme.manager');
-    }
     $this->themeManager = $theme_manager;
   }
 

core/lib/Drupal/Core/Theme/Registry.php

@@ -812,22 +812,4 @@ class Registry implements DestructableInterface {
     return $grouped_functions;
   }
 
-  /**
-   * Wraps drupal_get_path().
-   *
-   * @param string $module
-   *   The name of the item for which the path is requested.
-   *
-   * @return string
-   *
-   * @deprecated in drupal:9.3.0 and is removed from drupal:10.0.0. Use
-   *   \Drupal\Core\Extension\ExtensionList::getPath() instead.
-   *
-   * @see https://www.drupal.org/node/2940438
-   */
-  protected function getPath($module) {
-    @trigger_error(__METHOD__ . ' is deprecated in drupal:9.3.0 and is removed from drupal:10.0.0. Use \Drupal\Core\Extension\ExtensionList::getPath() instead. See https://www.drupal.org/node/2940438', E_USER_DEPRECATED);
-    return $this->moduleList->getPath($module);
-  }
-
 }

core/lib/Drupal/Core/Theme/ThemeInitialization.php

@@ -138,20 +138,10 @@ class ThemeInitialization implements ThemeInitializationInterface {
     if ($theme_engine = $active_theme->getEngine()) {
       // Include the engine.
       include_once $this->root . '/' . $active_theme->getOwner();
-
-      if (function_exists($theme_engine . '_init')) {
-        @trigger_error('THEME_ENGINE_init() is deprecated in drupal:9.3.0 and removed in drupal:10.0.0. There is no replacement. See https://www.drupal.org/node/3246978', E_USER_DEPRECATED);
-        foreach ($active_theme->getBaseThemeExtensions() as $base) {
-          call_user_func($theme_engine . '_init', $base);
-        }
-        call_user_func($theme_engine . '_init', $active_theme->getExtension());
-      }
-      else {
-        foreach ($active_theme->getBaseThemeExtensions() as $base) {
-          $base->load();
-        }
-        $active_theme->getExtension()->load();
+      foreach ($active_theme->getBaseThemeExtensions() as $base) {
+        $base->load();
       }
+      $active_theme->getExtension()->load();
     }
     else {
       // include non-engine theme files

core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php

@@ -30,15 +30,8 @@ class EngineNyanCatTest extends BrowserTestBase {
 
   /**
    * Ensures a theme's template is overridable based on the 'template' filename.
-   *
-   * @group legacy
-   *
-   * @todo https://www.drupal.org/project/drupal/issues/3246981 Remove
-   *   nyan_cat_init() and the legacy group and expected deprecation from this
-   *   test.
    */
   public function testTemplateOverride() {
-    $this->expectDeprecation('THEME_ENGINE_init() is deprecated in drupal:9.3.0 and removed in drupal:10.0.0. There is no replacement. See https://www.drupal.org/node/3246978');
     $this->config('system.theme')
       ->set('default', 'test_theme_nyan_cat_engine')
       ->save();

core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine

@@ -7,16 +7,6 @@
 
 use Drupal\Core\Extension\Extension;
 
-/**
- * Includes .theme file from themes.
- *
- * @param \Drupal\Core\Extension\Extension $theme
- *   The theme extension object.
- */
-function nyan_cat_init(Extension $theme) {
-  $theme->load();
-}
-
 /**
  * Implements hook_theme().
  */

core/tests/Drupal/Tests/Core/Theme/RegistryTest.php

@@ -89,7 +89,8 @@ class RegistryTest extends UnitTestCase {
     $this->themeInitialization = $this->createMock('Drupal\Core\Theme\ThemeInitializationInterface');
     $this->themeManager = $this->createMock('Drupal\Core\Theme\ThemeManagerInterface');
     $this->moduleList = $this->createMock(ModuleExtensionList::class);
-    $this->setupTheme();
+    $this->registry = new Registry($this->root, $this->cache, $this->lock, $this->moduleHandler, $this->themeHandler, $this->themeInitialization, NULL, NULL, $this->moduleList);
+    $this->registry->setThemeManager($this->themeManager);
   }
 
   /**
@@ -484,21 +485,6 @@ class RegistryTest extends UnitTestCase {
     return $data;
   }
 
-  protected function setupTheme() {
-    $this->registry = $this->getMockBuilder(Registry::class)
-      ->onlyMethods(['getPath'])
-      ->setConstructorArgs([$this->root, $this->cache, $this->lock, $this->moduleHandler, $this->themeHandler, $this->themeInitialization, NULL, NULL, $this->moduleList])
-      ->getMock();
-    $this->registry->expects($this->any())
-      ->method('getPath')
-      ->willReturnCallback(function ($module) {
-        if ($module == 'theme_test') {
-          return 'core/modules/system/tests/modules/theme_test';
-        }
-      });
-    $this->registry->setThemeManager($this->themeManager);
-  }
-
 }
 
 namespace Drupal\Core\Theme;