diff --git a/core/includes/batch.inc b/core/includes/batch.inc
index 3a835e5..c8db02a 100644
--- a/core/includes/batch.inc
+++ b/core/includes/batch.inc
@@ -100,7 +100,7 @@ function _batch_do() {
   // Perform actual processing.
   /** @var \Drupal\Core\Batch\BatchProcessorInterface */
   $batch_processor = \Drupal::service('batch.processor');
-  list($percentage, $message, $label) = $batch_processor->process();
+  list($percentage, $message, $label) = $batch_processor->processBatchSet();
 
   return new JsonResponse(array('status' => TRUE, 'percentage' => $percentage, 'message' => $message, 'label' => $label));
 }
@@ -151,7 +151,7 @@ function _batch_progress_page() {
     print $fallback;
 
     // Perform actual processing.
-    list($percentage, $message, $label) = $batch_processor->process($batch);
+    list($percentage, $message, $label) = $batch_processor->processBatchSet($batch);
     if ($percentage == 100) {
       $new_op = 'finished';
     }
diff --git a/core/includes/form.inc b/core/includes/form.inc
index 8f381ae..945f2b4 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -795,9 +795,91 @@ function batch_set($batch_definition) {
  *   A redirect response if the batch is progressive. No return value otherwise.
  */
 function batch_process($redirect = NULL, Url $url = NULL, $redirect_callback = NULL) {
-  /** @var \Drupal\Core\Batch\BatchProcessorInterface */
-  $batch_processor = \Drupal::service('batch.processor');
-  return $batch_processor->process($redirect, $url, $redirect_callback);
+  $batch =& batch_get();
+
+  if (isset($batch)) {
+    // Add process information
+    $process_info = array(
+      'current_set' => 0,
+      'progressive' => TRUE,
+      'url' => isset($url) ? $url : Url::fromRoute('system.batch_page.html'),
+      'source_url' => Url::fromRouteMatch(\Drupal::routeMatch()),
+      'batch_redirect' => $redirect,
+      'theme' => \Drupal::theme()->getActiveTheme()->getName(),
+      'redirect_callback' => $redirect_callback,
+    );
+    $batch += $process_info;
+
+    // The batch is now completely built. Allow other modules to make changes
+    // to the batch so that it is easier to reuse batch processes in other
+    // environments.
+    \Drupal::moduleHandler()->alter('batch', $batch);
+
+    // Assign an arbitrary id: don't rely on a serial column in the 'batch'
+    // table, since non-progressive batches skip database storage completely.
+    $batch['id'] = db_next_id();
+
+    // Move operations to a job queue. Non-progressive batches will use a
+    // memory-based queue.
+    foreach ($batch['sets'] as $key => $batch_set) {
+      _batch_populate_queue($batch, $key);
+    }
+
+    // Initiate processing.
+    if ($batch['progressive']) {
+      // Now that we have a batch id, we can generate the redirection link in
+      // the generic error message.
+      /** @var \Drupal\Core\Url $batch_url */
+      $batch_url = $batch['url'];
+      /** @var \Drupal\Core\Url $error_url */
+      $error_url = clone $batch_url;
+      $query_options = $error_url->getOption('query');
+      $query_options['id'] = $batch['id'];
+      $query_options['op'] = 'finished';
+      $error_url->setOption('query', $query_options);
+
+      $batch['error_message'] = t('Please continue to <a href="@error_url">the error page</a>', array('@error_url' => $error_url->toString(TRUE)->getGeneratedUrl()));
+
+      // Clear the way for the redirection to the batch processing page, by
+      // saving and unsetting the 'destination', if there is any.
+      $request = \Drupal::request();
+      if ($request->query->has('destination')) {
+        $batch['destination'] = $request->query->get('destination');
+        $request->query->remove('destination');
+      }
+
+      // Store safe strings.
+      // @todo Ensure we are not storing an excessively large string list in:
+      //   https://www.drupal.org/node/2295823
+      $batch['safe_strings'] = SafeMarkup::getAll();
+
+      // Store the batch.
+      \Drupal::service('batch.storage')->create($batch);
+
+      // Set the batch number in the session to guarantee that it will stay alive.
+      $_SESSION['batches'][$batch['id']] = TRUE;
+
+      // Redirect for processing.
+      $query_options = $error_url->getOption('query');
+      $query_options['op'] = 'start';
+      $query_options['id'] = $batch['id'];
+      $batch_url->setOption('query', $query_options);
+      if (($function = $batch['redirect_callback']) && function_exists($function)) {
+        $function($batch_url->toString(), ['query' => $query_options]);
+      }
+      else {
+        return new RedirectResponse($batch_url->setAbsolute()->toString(TRUE)->getGeneratedUrl());
+      }
+    }
+    else {
+      // Non-progressive execution: bypass the whole progressbar workflow
+      // and execute the batch in one pass.
+      require_once __DIR__ . '/batch.inc';
+      /** @var \Drupal\Core\Batch\BatchProcessorInterface $batch_processor */
+      $batch_processor = \Drupal::service('batch.processor');
+      $batch_processor->processBatchSet();
+    }
+  }
 }
 
 /**
diff --git a/core/lib/Drupal/Core/Batch/BatchProcessor.php b/core/lib/Drupal/Core/Batch/BatchProcessor.php
index e1507ba..29319cb 100644
--- a/core/lib/Drupal/Core/Batch/BatchProcessor.php
+++ b/core/lib/Drupal/Core/Batch/BatchProcessor.php
@@ -10,9 +10,14 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Component\Utility\Timer;
 use Drupal\Component\Utility\UrlHelper;
+use Drupal\Core\Database\Database;
 use Drupal\Core\Datetime\DateFormatter;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\FormState;
 use Drupal\Core\Form\FormSubmitterInterface;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Drupal\Core\Theme\ThemeManagerInterface;
 use Drupal\Core\Url;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\RequestStack;
@@ -22,6 +27,8 @@
  */
 class BatchProcessor implements BatchProcessorInterface {
 
+  use StringTranslationTrait;
+
   /**
    * The set of batches.
    *
@@ -98,115 +105,6 @@ public function __construct($root, BatchQueueHandlerInterface $batch_queue, Date
   }
 
   /**
-   * Processes the batch.
-   *
-   * This function is generally not needed in form submit handlers;
-   * Form API takes care of batches that were set during form submission.
-   *
-   * @param \Drupal\Core\Url|string $redirect
-   *   (optional) Either path or Url object to redirect to when the batch has
-   *   finished processing. Note that to simply force a batch to (conditionally)
-   *   redirect to a custom location after it is finished processing but to
-   *   otherwise allow the standard form API batch handling to occur, it is not
-   *   necessary to call batch_process() and use this parameter. Instead, make
-   *   the batch 'finished' callback return an instance of
-   *   \Symfony\Component\HttpFoundation\RedirectResponse, which will be used
-   *   automatically by the standard batch processing pipeline (and which takes
-   *   precedence over this parameter).
-   * @param \Drupal\Core\Url $url
-   *   (optional - should only be used for separate scripts like update.php)
-   *   URL of the batch processing page.
-   * @param $redirect_callback
-   *   (optional) Specify a function to be called to redirect to the progressive
-   *   processing page.
-   *
-   * @return \Symfony\Component\HttpFoundation\RedirectResponse|null
-   *   A redirect response if the batch is progressive. No return value otherwise.
-   */
-  public function process($redirect = NULL, Url $url = NULL, $redirect_callback = NULL) {
-    if (isset($this->batch)) {
-      // Add process information
-      $process_info = array(
-        'current_set' => 0,
-        'progressive' => TRUE,
-        'url' => isset($url) ? $url : Url::fromRoute('system.batch_page.html'),
-        'source_url' => Url::fromRouteMatch(\Drupal::routeMatch() ),
-        'batch_redirect' => $redirect,
-        'theme' => \Drupal::theme()->getActiveTheme()->getName(),
-        'redirect_callback' => $redirect_callback,
-      );
-      $this->batch += $process_info;
-
-      // The batch is now completely built. Allow other modules to make changes
-      // to the batch so that it is easier to reuse batch processes in other
-      // environments.
-      \Drupal::moduleHandler()->alter('batch', $this->batch);
-
-      // Assign an arbitrary id: don't rely on a serial column in the 'batch'
-      // table, since non-progressive batches skip database storage completely.
-      $this->batch['id'] = db_next_id();
-
-      // Move operations to a job queue. Non-progressive batches will use a
-      // memory-based queue.
-      foreach ($this->batch['sets'] as $key => $batch_set) {
-        _batch_populate_queue($this->batch, $key);
-      }
-
-      // Initiate processing.
-      if ($this->batch['progressive']) {
-        // Now that we have a batch id, we can generate the redirection link in
-        // the generic error message.
-        /** @var \Drupal\Core\Url $batch_url */
-        $batch_url = $this->batch['url'];
-        /** @var \Drupal\Core\Url $error_url */
-        $error_url = clone $batch_url;
-        $query_options = $error_url->getOption('query');
-        $query_options['id'] = $this->batch['id'];
-        $query_options['op'] = 'finished';
-        $error_url->setOption('query', $query_options);
-
-        $this->batch['error_message'] = t('Please continue to <a href="@error_url">the error page</a>', array('@error_url' => $error_url->toString(TRUE)->getGeneratedUrl()));
-
-        // Clear the way for the redirection to the batch processing page, by
-        // saving and unsetting the 'destination', if there is any.
-        $request = \Drupal::request();
-        if ($request->query->has('destination')) {
-          $this->batch['destination'] = $request->query->get('destination');
-          $request->query->remove('destination');
-        }
-
-        // Store safe strings.
-        // @todo Ensure we are not storing an excessively large string list in:
-        //   https://www.drupal.org/node/2295823
-        $this->batch['safe_strings'] = SafeMarkup::getAll();
-
-        // Store the batch.
-        $this->batchStorage->create($this->batch);
-
-        // Set the batch number in the session to guarantee that it will stay alive.
-        $_SESSION['batches'][$this->batch['id']] = TRUE;
-
-        // Redirect for processing.
-        $query_options = $error_url->getOption('query');
-        $query_options['op'] = 'start';
-        $query_options['id'] = $this->batch['id'];
-        $batch_url->setOption('query', $query_options);
-        if (($function = $this->batch['redirect_callback']) && function_exists($function)) {
-          $function($batch_url->toString(), ['query' => $query_options]);
-        }
-        else {
-          return new RedirectResponse($batch_url->setAbsolute()->toString(TRUE)->getGeneratedUrl());
-        }
-      }
-      else {
-        // Non-progressive execution: bypass the whole progressbar workflow
-        // and execute the batch in one pass.
-        $this->processBatchSet();
-      }
-    }
-  }
-
-  /**
    * {@inheritdoc}
    */
   public function processBatchSet() {
@@ -340,14 +238,13 @@ public function processBatchSet() {
    * {@inheritdoc}
    */
   public function currentSet() {
-    $this->batch = &batch_get();
     return $this->batch['sets'][$this->batch['current_set']];
   }
 
   /**
    * @return array
    */
-  public function getBatch() {
+  public function &getBatch() {
     return $this->batch;
   }
 
@@ -472,5 +369,23 @@ public function finished() {
     }
   }
 
+  /**
+   * @return mixed
+   */
+  protected function getBatchId() {
+    return Database::getConnection()->nextId();
+  }
+
+  /**
+   * @param $error_url
+   * @return string
+   */
+  protected function getErrorMessage(Url $error_url) {
+    return $this->t('Please continue to <a href="@error_url">the error page</a>', array(
+      '@error_url' => $error_url->toString(TRUE)
+        ->getGeneratedUrl()
+    ));
+  }
+
 
 }
diff --git a/core/tests/Drupal/Tests/Core/Batch/BatchProcessorTest.php b/core/tests/Drupal/Tests/Core/Batch/BatchProcessorTest.php
index c4af0be..cd992de 100644
--- a/core/tests/Drupal/Tests/Core/Batch/BatchProcessorTest.php
+++ b/core/tests/Drupal/Tests/Core/Batch/BatchProcessorTest.php
@@ -11,9 +11,22 @@
 use Drupal\Core\Batch\BatchQueueHandlerInterface;
 use Drupal\Core\Batch\BatchStorageInterface;
 use Drupal\Core\Datetime\DateFormatter;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\FormSubmitterInterface;
+use Drupal\Core\GeneratedUrl;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Routing\UrlGeneratorInterface;
+use Drupal\Core\Theme\ActiveTheme;
+use Drupal\Core\Theme\ThemeManagerInterface;
+use Drupal\Core\Url;
 use Drupal\Tests\UnitTestCase;
+use Prophecy\Argument;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\HttpFoundation\ParameterBag;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\Routing\Route;
 
 /**
  * @coversDefaultClass \Drupal\Core\Batch\BatchProcessor
@@ -71,6 +84,38 @@ protected function setupBatchProcessor() {
     return new BatchProcessor('core', $this->batchQueue->reveal(), $this->dateFormatter->reveal(), $this->formSubmitter->reveal(), $this->batchStorage->reveal(), $this->requestStack);
   }
 
+  protected function setupThemeManager() {
+    $this->themeManager->getActiveTheme()->willReturn(new ActiveTheme(['name' => 'example']));
+  }
+
+  protected function setupRouteMatch() {
+    $this->routeMatch->getRouteObject()->willReturn(new Route('/test'));
+    $this->routeMatch->getRouteName()->willReturn('test');
+    $this->routeMatch->getRawParameters()->willReturn(new ParameterBag());
+  }
+
+  protected function setupRequest() {
+    $request = Request::create('/test');
+    $this->requestStack->push($request);
+  }
+
+  protected function setupBasicBatch() {
+    $batch = [
+      'current_set' => 0,
+      'progressive' => TRUE,
+      'url' => Url::fromRoute('system.batch_page.html'),
+      'source_url' => Url::fromRoute('<front>'),
+      'theme' => 'example_theme',
+      'sets' => [],
+    ];
+    return $batch;
+  }
+
+  protected function setBatchWithOneSet() {
+    $batch = $this->setupBasicBatch();
+    $batch['sets'][0] =
+  }
+
   /**
    * @covers ::getBatch
    */
@@ -80,4 +125,24 @@ public function testGetEmptyBatch() {
     $this->assertEquals(['sets' => []], $batch->getBatch());
   }
 
+// @todo Throws an assertion ATM.
+//  public function testProcessBatchSetWithNoCurrentSet() {
+//    $batch = $this->setupBatchProcessor();
+//
+//    $batch->processBatchSet();
+//  }
+
+  public function testProcessBatchSetWithInitialSet() {
+    $this->batchStorage->load()->willReturn($this->setupBasicBatch());
+
+    $batch_processor = $this->setupBatchProcessor();
+
+    $batch = &$batch_processor->getBatch();
+    $batch = $this->setupBasicBatch();
+
+    $result = $batch_processor->processBatchSet();
+    print_r($result);
+  }
+
 }
+