class TaxonomyRelationshipTest

class TaxonomyRelationshipTest extends TaxonomyTestBase {
  
  /**
   * Stores the terms used in the tests.
   *
   * @var \Drupal\taxonomy\TermInterface[]
   */
  protected $terms = [];
  
  /**
   * Views used by this test.
   *
   * @var array
   */
  public static $testViews = [
    'test_taxonomy_term_relationship',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected function setUp($import_test_views = TRUE) : void {
    parent::setUp($import_test_views);
    $this->installSchema('node', [
      'node_access',
    ]);
    // Make term2 parent of term1.
    $this->term1
      ->set('parent', $this->term2
      ->id());
    $this->term1
      ->save();
    // Store terms in an array for testing.
    $this->terms[] = $this->term1;
    $this->terms[] = $this->term2;
    // Only set term1 on node1 and term2 on node2 for testing.
    unset($this->nodes[0]->field_views_testing_tags[1]);
    $this->nodes[0]
      ->save();
    unset($this->nodes[1]->field_views_testing_tags[0]);
    $this->nodes[1]
      ->save();
    Views::viewsData()->clear();
  }
  
  /**
   * Tests the taxonomy parent plugin UI.
   */
  public function testTaxonomyRelationships() : void {
    // Check the generated views data of taxonomy_index.
    $views_data = Views::viewsData()->get('taxonomy_index');
    // Check the table join data.
    $this->assertEquals('tid', $views_data['table']['join']['taxonomy_term_field_data']['left_field']);
    $this->assertEquals('tid', $views_data['table']['join']['taxonomy_term_field_data']['field']);
    $this->assertEquals('nid', $views_data['table']['join']['node_field_data']['left_field']);
    $this->assertEquals('nid', $views_data['table']['join']['node_field_data']['field']);
    $this->assertEquals('entity_id', $views_data['table']['join']['taxonomy_term__parent']['left_field']);
    $this->assertEquals('tid', $views_data['table']['join']['taxonomy_term__parent']['field']);
    // Check the generated views data of taxonomy_term__parent.
    $views_data = Views::viewsData()->get('taxonomy_term__parent');
    // Check the table join data.
    $this->assertEquals('entity_id', $views_data['table']['join']['taxonomy_term__parent']['left_field']);
    $this->assertEquals('parent_target_id', $views_data['table']['join']['taxonomy_term__parent']['field']);
    $this->assertEquals('tid', $views_data['table']['join']['taxonomy_term_field_data']['left_field']);
    $this->assertEquals('entity_id', $views_data['table']['join']['taxonomy_term_field_data']['field']);
    // Check the parent relationship data.
    $this->assertEquals('taxonomy_term_field_data', $views_data['parent_target_id']['relationship']['base']);
    $this->assertEquals('tid', $views_data['parent_target_id']['relationship']['base field']);
    $this->assertEquals('Parent', $views_data['parent_target_id']['relationship']['label']);
    $this->assertEquals('standard', $views_data['parent_target_id']['relationship']['id']);
    // Check the parent filter and argument data.
    $this->assertEquals('numeric', $views_data['parent_target_id']['filter']['id']);
    $this->assertEquals('taxonomy', $views_data['parent_target_id']['argument']['id']);
    // Check an actual test view.
    $view = Views::getView('test_taxonomy_term_relationship');
    $this->executeView($view);
    /** @var \Drupal\views\ResultRow $row */
    foreach ($view->result as $index => $row) {
      // Check that the actual ID of the entity is the expected one.
      $this->assertEquals($this->terms[$index]
        ->id(), $row->tid);
      // Also check that we have the correct result entity.
      $this->assertEquals($this->terms[$index]
        ->id(), $row->_entity
        ->id());
      $this->assertInstanceOf(TermInterface::class, $row->_entity);
      if (!$index) {
        $this->assertInstanceOf(TermInterface::class, $row->_relationship_entities['parent']);
        $this->assertEquals($this->term2
          ->id(), $row->_relationship_entities['parent']
          ->id());
        $this->assertEquals($this->term2
          ->id(), $row->taxonomy_term_field_data_taxonomy_term__parent_tid);
      }
      $this->assertInstanceOf(NodeInterface::class, $row->_relationship_entities['nid']);
      $this->assertEquals($this->nodes[$index]
        ->id(), $row->_relationship_entities['nid']
        ->id());
    }
    // Test node fields are available through relationship.
    \Drupal::service('module_installer')->install([
      'views_ui',
    ]);
    $this->setCurrentUser($this->createUser([
      'administer views',
    ]));
    $this->drupalGet('admin/structure/views/view/test_taxonomy_term_relationship');
    $this->getSession()
      ->getPage()
      ->find('css', '#views-add-field')
      ->click();
    $this->assertSession()
      ->pageTextContains('Body');
  }

}