Issue #3252097: Remove PathLocator::getStageDirectory()

tests/src/Functional/FileSystemOperationsTest.php

@@ -59,7 +59,7 @@ class FileSystemOperationsTest extends AutomaticUpdatesFunctionalTestBase {
     $locator->getProjectRoot()->willReturn($drupal_root);
     $locator->getWebRoot()->willReturn('');
 
-    $this->updater = new Updater(
+    $this->updater = new class(
       $locator->reveal(),
       $this->container->get('package_manager.beginner'),
       $this->container->get('package_manager.stager'),
@@ -67,7 +67,24 @@ class FileSystemOperationsTest extends AutomaticUpdatesFunctionalTestBase {
       $this->container->get('file_system'),
       $this->container->get('event_dispatcher'),
       $this->container->get('tempstore.shared')
-    );
+    ) extends Updater {
+
+      /**
+       * The directory where staging areas will be created.
+       *
+       * @var string
+       */
+      public static $stagingRoot;
+
+      /**
+       * {@inheritdoc}
+       */
+      protected static function getStagingRoot(): string {
+        return static::$stagingRoot;
+      }
+
+    };
+    $this->updater::$stagingRoot = $this->stageDir;
 
     // Use the public and private files directories in the fake site fixture.
     $settings = Settings::getAll();