Issue #3343670 by tim-diels, shalini_jha, jecet4, mschudders, graber, enaznin,...

Issue #3343670 by tim-diels, shalini_jha, jecet4, mschudders, graber, enaznin, smustgrave: Allow to merge AjaxCommands inside of AjaxResponse

core/lib/Drupal/Core/Ajax/AjaxResponse.php

@@ -55,6 +55,23 @@ public function addCommand(CommandInterface $command, $prepend = FALSE) {
     return $this;
   }
 
+  /**
+   * Merges other ajax response with this one.
+   *
+   * Adds commands and merges attachments from the other ajax response.
+   *
+   * @param \Drupal\Core\Ajax\AjaxResponse $other
+   *   An AJAX response to merge.
+   *
+   * @return $this
+   *   Returns this after merging.
+   */
+  public function mergeWith(AjaxResponse $other): AjaxResponse {
+    $this->commands = array_merge($this->getCommands(), $other->getCommands());
+    $this->attachments = BubbleableMetadata::mergeAttachments($this->getAttachments(), $other->getAttachments());
+    return $this;
+  }
+
   /**
    * Gets all AJAX commands.
    *

core/tests/Drupal/Tests/Core/Ajax/AjaxResponseTest.php

@@ -5,6 +5,7 @@
 namespace Drupal\Tests\Core\Ajax;
 
 use Drupal\Core\Ajax\AjaxResponse;
+use Drupal\Core\Ajax\CommandInterface;
 use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\HttpFoundation\Request;
@@ -98,4 +99,95 @@ public function testPrepareResponseForIeFormRequestsWithFileUpload(): void {
     $this->assertEquals('<textarea>[]</textarea>', $response->getContent());
   }
 
+  /**
+   * Tests the mergeWith() method.
+   *
+   * @see \Drupal\Core\Ajax\AjaxResponse::mergeWith()
+   *
+   * @throws \PHPUnit\Framework\MockObject\Exception
+   */
+  public function testMergeWithOtherAjaxResponse(): void {
+    $response = new AjaxResponse([]);
+
+    $command_one = $this->createCommandMock('one');
+
+    $command_two = $this->createCommandMockWithSettingsAndLibrariesAttachments(
+      'Drupal\Core\Ajax\HtmlCommand', [
+        'setting1' => 'value1',
+        'setting2' => 'value2',
+      ], ['jquery', 'drupal'], 'two');
+    $command_three = $this->createCommandMockWithSettingsAndLibrariesAttachments(
+      'Drupal\Core\Ajax\InsertCommand', [
+        'setting1' => 'overridden',
+        'setting3' => 'value3',
+      ], ['jquery', 'ajax'], 'three');
+
+    $response->addCommand($command_one);
+    $response->addCommand($command_two);
+
+    $response2 = new AjaxResponse([]);
+    $response2->addCommand($command_three);
+
+    $response->mergeWith($response2);
+    self::assertEquals([
+      'library' => ['jquery', 'drupal', 'jquery', 'ajax'],
+      'drupalSettings' => [
+        'setting1' => 'overridden',
+        'setting2' => 'value2',
+        'setting3' => 'value3',
+      ],
+    ], $response->getAttachments());
+    self::assertEquals([['command' => 'one'], ['command' => 'two'], ['command' => 'three']], $response->getCommands());
+  }
+
+  /**
+   * Creates a mock of a provided subclass of CommandInterface.
+   *
+   * Adds given settings and libraries to assets mock
+   * that is attached to the command mock.
+   *
+   * @param string $command_class_name
+   *   The command class name to create the mock for.
+   * @param array|null $settings
+   *   The settings to attach.
+   * @param array|null $libraries
+   *   The libraries to attach.
+   * @param string $command_name
+   *   The command name to pass to the mock.
+   */
+  private function createCommandMockWithSettingsAndLibrariesAttachments(
+    string $command_class_name,
+    array|null $settings,
+    array|null $libraries,
+    string $command_name,
+  ): CommandInterface {
+    $command = $this->createMock($command_class_name);
+    $command->expects($this->once())
+      ->method('render')
+      ->willReturn(['command' => $command_name]);
+
+    $assets = $this->createMock('Drupal\Core\Asset\AttachedAssetsInterface');
+    $assets->expects($this->once())->method('getLibraries')->willReturn($libraries);
+    $assets->expects($this->once())->method('getSettings')->willReturn($settings);
+
+    $command->expects($this->once())->method('getAttachedAssets')->willReturn($assets);
+
+    return $command;
+  }
+
+  /**
+   * Creates a mock of the Drupal\Core\Ajax\CommandInterface.
+   *
+   * @param string $command_name
+   *   The command name to pass to the mock.
+   */
+  private function createCommandMock(string $command_name): CommandInterface {
+    $command = $this->createMock('Drupal\Core\Ajax\CommandInterface');
+    $command->expects($this->once())
+      ->method('render')
+      ->willReturn(['command' => $command_name]);
+
+    return $command;
+  }
+
 }