class TaxonomyTermReferenceFieldTest

class TaxonomyTermReferenceFieldTest extends UnitTestCase {
  
  /**
   * @var \Drupal\migrate_drupal\Plugin\MigrateFieldInterface
   */
  protected $plugin;
  
  /**
   * @var \Drupal\migrate\Plugin\MigrationInterface
   */
  protected $migration;
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    $this->plugin = new TaxonomyTermReference([], 'taxonomy', []);
    $migration = $this->prophesize(MigrationInterface::class);
    // The plugin's defineValueProcessPipeline() method will call
    // setProcessOfProperty() and return nothing. So, in order to examine the
    // process pipeline created by the plugin, we need to ensure that
    // getProcess() always returns the last input to setProcessOfProperty().
    $migration->setProcessOfProperty(Argument::type('string'), Argument::type('array'))
      ->will(function ($arguments) use ($migration) {
      $migration->getProcess()
        ->willReturn($arguments[1]);
    });
    $this->migration = $migration->reveal();
  }
  
  /**
   * @covers ::defineValueProcessPipeline
   */
  public function testDefineValueProcessPipeline($method = 'defineValueProcessPipeline') {
    $this->plugin
      ->{$method}($this->migration, 'field_name', []);
    $expected = [
      'plugin' => 'sub_process',
      'source' => 'field_name',
      'process' => [
        'target_id' => 'tid',
      ],
    ];
    $this->assertSame($expected, $this->migration
      ->getProcess());
  }

}