Issue #3248929: List update that will be applied on the UpdateReady form

package_manager/tests/modules/package_manager_bypass/src/Stager.php

@@ -4,17 +4,56 @@ namespace Drupal\package_manager_bypass;
 
 use PhpTuf\ComposerStager\Domain\Process\OutputCallbackInterface;
 use PhpTuf\ComposerStager\Domain\StagerInterface;
+use Symfony\Component\Filesystem\Filesystem;
 
 /**
  * Defines an update stager which doesn't actually do anything.
  */
 class Stager extends InvocationRecorderBase implements StagerInterface {
 
+  /**
+   * The fixtures state key.
+   *
+   * @var string
+   */
+  protected const FIXTURES_STATE_KEY = 'package_manager_bypass_stager_fixtures_path';
+
+  /**
+   * The fixtures state key.
+   *
+   * @var string
+   */
+  protected const DIRECTORIES_CREATED_STATE_KEY = 'package_manager_bypass_stager_directories_created';
+
   /**
    * {@inheritdoc}
    */
   public function stage(array $composerCommand, string $stagingDir, ?OutputCallbackInterface $callback = NULL, ?int $timeout = 120): void {
+    $fixturesDirectoryPath = \Drupal::state()->get(static::FIXTURES_STATE_KEY);
+    if ($fixturesDirectoryPath) {
+      if (!file_exists($stagingDir)) {
+        mkdir($stagingDir);
+        $directories_created = \Drupal::state()->get(static::DIRECTORIES_CREATED_STATE_KEY, []);
+        $directories_created[] = $stagingDir;
+        \Drupal::state()->set(static::DIRECTORIES_CREATED_STATE_KEY, $directories_created);
+      }
+      $fileSystem = new Filesystem();
+      $fileSystem->mirror($fixturesDirectoryPath, $stagingDir);
+    }
     $this->saveInvocationArguments($composerCommand, $stagingDir);
   }
 
+  /**
+   * @param string $activeDir
+   * @param string $stagingDir
+   */
+  public function setTestFixtureDirectory(string $fixturesDirectoryPath):void {
+    \Drupal::state()->set(static::FIXTURES_STATE_KEY, $fixturesDirectoryPath);
+  }
+
+  public function deleteStagedDirectories():void {
+    $directories_created = \Drupal::state()->get(static::DIRECTORIES_CREATED_STATE_KEY);
+    $fileSystem = new Filesystem();
+    $fileSystem->remove($directories_created);
+  }
 }