class RelationshipJoinTestBase

abstract class RelationshipJoinTestBase extends PluginKernelTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'system',
        'user',
        'field',
    ];
    
    /**
     * @var \Drupal\user\Entity\User
     */
    protected $rootUser;
    
    /**
     * {@inheritdoc}
     */
    protected function setUpFixtures() {
        $this->installEntitySchema('user');
        $this->installConfig([
            'user',
        ]);
        parent::setUpFixtures();
        // Create a record for uid 1.
        $this->rootUser = User::create([
            'name' => $this->randomMachineName(),
        ]);
        $this->rootUser
            ->save();
        Views::viewsData()->clear();
    }
    
    /**
     * Overrides \Drupal\views\Tests\ViewTestBase::schemaDefinition().
     *
     * Adds a uid column to test the relationships.
     *
     * @internal
     */
    protected function schemaDefinition() {
        $schema = parent::schemaDefinition();
        $schema['views_test_data']['fields']['uid'] = [
            'description' => "The {users_field_data}.uid of the author of the beatle entry.",
            'type' => 'int',
            'unsigned' => TRUE,
            'not null' => TRUE,
            'default' => 0,
        ];
        return $schema;
    }
    
    /**
     * Overrides \Drupal\views\Tests\ViewTestBase::viewsData().
     *
     * Adds a relationship for the uid column.
     */
    protected function viewsData() {
        $data = parent::viewsData();
        $data['views_test_data']['uid'] = [
            'title' => new TranslatableMarkup('UID'),
            'help' => new TranslatableMarkup('The test data UID'),
            'relationship' => [
                'id' => 'standard',
                'base' => 'users_field_data',
                'base field' => 'uid',
            ],
        ];
        return $data;
    }

}