Issue #3035274 by claudiu.cristea, naveenvalecha, Berdir: Deprecate...

Issue #3035274 by claudiu.cristea, naveenvalecha, Berdir: Deprecate drupal_classloader_register() & system_register()

core/includes/bootstrap.inc

@@ -811,8 +811,21 @@ function drupal_get_profile() {
  *   The namespace component to register; e.g., 'node'.
  * @param string $path
  *   The relative path to the Drupal component in the filesystem.
+ *
+ * @deprecated in Drupal 8.8.0, will be removed before Drupal 9.0.0. Use the
+ *   class loader as injected service instance to register the namespace:
+ *   @code
+ *   $this->classLoader->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . $path . '/src');
+ *   @endcode
+ *   or the following code if the service cannot be injected:
+ *   @code
+ *   \Drupal::service('class_loader')->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . $path . '/src');
+ *   @endcode
+ *
+ * @see https://www.drupal.org/node/3035275
  */
 function drupal_classloader_register($name, $path) {
+  @trigger_error('drupal_classloader_register() is deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. Use the method ::addPsr4() of the class_loader service to register the namespace. See https://www.drupal.org/node/3035275.', E_USER_DEPRECATED);
   $loader = \Drupal::service('class_loader');
   $loader->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . $path . '/src');
 }

core/includes/install.inc

@@ -986,7 +986,7 @@ function drupal_check_profile($profile) {
         require_once $install_file;
       }
 
-      drupal_classloader_register($module, $module_path);
+      \Drupal::service('class_loader')->addPsr4('Drupal\\' . $module . '\\', \Drupal::root() . "/$module_path/src");
 
       if (function_exists($function)) {
         $requirements = array_merge($requirements, $function('install'));

core/includes/module.inc

@@ -69,10 +69,18 @@ function system_list_reset() {
  * @param string $uri
  *   The relative URI of the primary extension file; e.g.,
  *   'core/modules/node/node.module'.
+ *
+ * @deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. There is
+ *   no replacement for this function. Use the following sequence of code to
+ *   achieve the same functionality:
+ *   @code
+ *   $path = \Drupal::service("extension.list.$type")->getPath($name);
+ *   \Drupal::service('class_loader')->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . $path . '/src');
+ *   @endcode
  */
 function system_register($type, $name, $uri) {
-  drupal_get_filename($type, $name, $uri);
-  drupal_classloader_register($name, dirname($uri));
+  @trigger_error('system_register() is deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. There is no replacement for this function. To achieve the same functionality use this snippet: $path = \Drupal::service("extension.list.$type")->getPath($name); ' . "\\Drupal::service('class_loader')->addPsr4('Drupal\\\\' . \$name . '\\\\', \\Drupal::root() . '/' . \$path . '/src'); See https://www.drupal.org/node/3035275.", E_USER_DEPRECATED);
+  \Drupal::service('class_loader')->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . dirname($uri) . '/src');
 }
 
 /**

core/tests/Drupal/Tests/Core/ClassLoader/ClassLoaderTest.php

+<?php
+
+namespace Drupal\Tests\Core\ClassLoader;
+
+use Composer\Autoload\ClassLoader;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @group ClassLoader
+ * @group legacy
+ */
+class ClassLoaderTest extends UnitTestCase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $container = new ContainerBuilder();
+    $container->set('app.root', $this->root);
+    $class_loader = $this->prophesize(ClassLoader::class);
+    $class_loader->addPsr4('Drupal\\foo\\', $this->root . '/modules/bar/src')->shouldBeCalled();
+    $container->set('class_loader', $class_loader->reveal());
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @expectedDeprecation drupal_classloader_register() is deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. Use the method ::addPsr4() of the class_loader service to register the namespace. See https://www.drupal.org/node/3035275.
+   * @see drupal_classloader_register()
+   */
+  public function testDrupalClassloadeRegisterDeprecation() {
+    include_once $this->root . '/core/includes/bootstrap.inc';
+    drupal_classloader_register('foo', 'modules/bar');
+  }
+
+  /**
+   * @expectedDeprecation system_register() is deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. There is no replacement for this function. To achieve the same functionality use this snippet: $path = \Drupal::service("extension.list.$type")->getPath($name); \Drupal::service('class_loader')->addPsr4('Drupal\\' . $name . '\\', \Drupal::root() . '/' . $path . '/src'); See https://www.drupal.org/node/3035275.
+   * @see system_register()
+   */
+  public function testSystemRegisterDeprecation() {
+    include_once $this->root . '/core/includes/module.inc';
+    system_register('module', 'foo', 'modules/bar/foo.module');
+  }
+
+}