Issue #2528292 by Fabianx, dawehner: Decouple Error testing from relying on a cached on disk-container that is created by a different Kernel

core/lib/Drupal/Core/DrupalKernel.php

@@ -52,8 +52,6 @@ use Symfony\Component\Routing\Route;
  */
 class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
 
-  const CONTAINER_BASE_CLASS = '\Drupal\Core\DependencyInjection\Container';
-
   /**
    * Holds the container instance.
    *
@@ -815,7 +813,8 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
     \Drupal::setContainer($this->container);
 
     // If needs dumping flag was set, dump the container.
-    if ($this->containerNeedsDumping && !$this->dumpDrupalContainer($this->container, static::CONTAINER_BASE_CLASS)) {
+    $base_class = Settings::get('container_base_class', '\Drupal\Core\DependencyInjection\Container');
+    if ($this->containerNeedsDumping && !$this->dumpDrupalContainer($this->container, $base_class)) {
       $this->container->get('logger.factory')->get('DrupalKernel')->notice('Container cannot be written to disk');
     }
 

core/modules/system/src/Tests/System/ErrorContainerRebuildKernel.php

@@ -1,22 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\system\Tests\System\ErrorContainerRebuildKernel.
- */
-
-namespace Drupal\system\Tests\System;
-
-use Drupal\Core\DrupalKernel;
-
-/**
- * A kernel which produces a container which triggers an error.
- */
-class ErrorContainerRebuildKernel extends DrupalKernel {
-
-  /**
-   * {@inheritdoc}
-   */
-  const CONTAINER_BASE_CLASS = '\Drupal\system\Tests\Bootstrap\ErrorContainer';
-
-}

core/modules/system/src/Tests/System/ExceptionContainerRebuildKernel.php

@@ -1,22 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\system\Tests\System\ExceptionContainerRebuildKernel.
- */
-
-namespace Drupal\system\Tests\System;
-
-use Drupal\Core\DrupalKernel;
-
-/**
- * A kernel which produces a container which triggers an exception.
- */
-class ExceptionContainerRebuildKernel extends DrupalKernel {
-
-  /**
-   * {@inheritdoc}
-   */
-  const CONTAINER_BASE_CLASS = '\Drupal\system\Tests\Bootstrap\ExceptionContainer';
-
-}

core/modules/system/src/Tests/System/UncaughtExceptionTest.php

@@ -108,10 +108,17 @@ class UncaughtExceptionTest extends WebTestBase {
    * Tests a container which has an error.
    */
   public function testErrorContainer() {
-    $kernel = ErrorContainerRebuildKernel::createFromRequest($this->prepareRequestForGenerator(), $this->classLoader, 'prod', TRUE);
+    $settings = [];
-    $kernel->rebuildContainer();
+    $settings['settings']['container_base_class'] = (object) [
+      'value' => '\Drupal\system\Tests\Bootstrap\ErrorContainer',
+      'required' => TRUE,
+    ];
+    $this->writeSettings($settings);
+
+    // Need to rebuild the container, so the dumped container can be tested
+    // and not the container builder.
+    \Drupal::service('kernel')->rebuildContainer();
 
-    $this->prepareRequestForGenerator();
     // Ensure that we don't use the now broken generated container on the test
     // process.
     \Drupal::setContainer($this->container);
@@ -137,10 +144,17 @@ class UncaughtExceptionTest extends WebTestBase {
    * Tests a container which has an exception really early.
    */
   public function testExceptionContainer() {
-    $kernel = ExceptionContainerRebuildKernel::createFromRequest($this->prepareRequestForGenerator(), $this->classLoader, 'prod', TRUE);
+    $settings = [];
-    $kernel->rebuildContainer();
+    $settings['settings']['container_base_class'] = (object) [
+      'value' => '\Drupal\system\Tests\Bootstrap\ExceptionContainer',
+      'required' => TRUE,
+    ];
+    $this->writeSettings($settings);
+
+    // Need to rebuild the container, so the dumped container can be tested
+    // and not the container builder.
+    \Drupal::service('kernel')->rebuildContainer();
 
-    $this->prepareRequestForGenerator();
     // Ensure that we don't use the now broken generated container on the test
     // process.
     \Drupal::setContainer($this->container);

sites/default/default.settings.php

@@ -632,6 +632,15 @@ if ($settings['hash_salt']) {
  */
 $settings['container_yamls'][] = __DIR__ . '/services.yml';
 
+/**
+ * Override the default service container class.
+ *
+ * This is useful for example to trace the service container for performance
+ * tracking purposes, for testing a service container with an error condition or
+ * to test a service container that throws an exception.
+ */
+# $settings['container_base_class'] = '\Drupal\Core\DependencyInjection\Container';
+
 /**
  * Trusted host configuration.
  *