add getIteratorMock

Closes #3520128

core/tests/Drupal/Tests/Core/Entity/EntityViewBuilderTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\Core\Entity;
+
+use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
+use Drupal\Core\Entity\EntityViewBuilder;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Entity\EntityViewBuilder
+ * @group Entity
+ */
+class EntityViewBuilderTest extends UnitTestCase {
+
+  const string ENTITY_TYPE_ID = 'test_entity_type';
+
+  /**
+   * The entity view builder under test.
+   *
+   * @var \Drupal\Core\Entity\EntityViewBuilder
+   */
+  protected EntityViewBuilder $viewBuilder;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->viewBuilder = new class() extends EntityViewBuilder {
+
+      public function __construct() {
+        $this->entityTypeId = EntityViewBuilderTest::ENTITY_TYPE_ID;
+      }
+
+    };
+  }
+
+  /**
+   * Tests build components using a mocked Iterator.
+   */
+  public function testBuildComponents(): void {
+    $field_name = $this->randomMachineName();
+    $bundle = $this->randomMachineName();
+    $entity_id = mt_rand(20, 30);
+    $field_item_list = $this->createStub(FieldItemListInterface::class);
+    $item = new \stdClass();
+    $this->setupMockIterator($field_item_list, [$item]);
+    $entity = $this->createConfiguredStub(FieldableEntityInterface::class, [
+      'bundle' => $bundle,
+      'hasField' => TRUE,
+      'get' => $field_item_list,
+    ]);
+    $formatter_result = [
+      $entity_id => ['#' . $this->randomMachineName() => $this->randomString()],
+    ];
+    $display = $this->createConfiguredStub(EntityViewDisplayInterface::class, [
+      'getComponents' => [$field_name => []],
+      'buildMultiple' => $formatter_result,
+    ]);
+    $entities = [$entity_id => $entity];
+    $displays = [$bundle => $display];
+    $build = [$entity_id => []];
+    $view_mode = $this->randomMachineName();
+    // Assert the hook is invoked.
+    $module_handler = $this->createMock(ModuleHandlerInterface::class);
+    $module_handler->expects($this->once())
+      ->method('invokeAll')
+      ->with('entity_prepare_view', [self::ENTITY_TYPE_ID, $entities, $displays, $view_mode]);
+    $this->viewBuilder->setModuleHandler($module_handler);
+    $this->viewBuilder->buildComponents($build, $entities, $displays, $view_mode);
+    $this->assertSame([], $item->_attributes);
+    $this->assertSame($formatter_result, $build);
+  }
+
+}