class MigrateSourceTestBase

abstract class MigrateSourceTestBase extends KernelTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'migrate',
  ];
  
  /**
   * The mocked migration.
   *
   * @var \Drupal\migrate\Plugin\MigrationInterface|\Prophecy\Prophecy\ObjectProphecy
   */
  protected $migration;
  
  /**
   * The source plugin under test.
   *
   * @var \Drupal\migrate\Plugin\MigrateSourceInterface
   */
  protected $plugin;
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    // Create a mock migration. This will be injected into the source plugin
    // under test.
    $this->migration = $this->prophesize(MigrationInterface::class);
    $this->migration
      ->id()
      ->willReturn($this->randomMachineName(16));
    // Prophesize a useless ID map plugin and an empty set of destination IDs.
    // Calling code can override these prophecies later and set up different
    // behaviors.
    $this->migration
      ->getIdMap()
      ->willReturn($this->prophesize(MigrateIdMapInterface::class)
      ->reveal());
    $this->migration
      ->getDestinationIds()
      ->willReturn([]);
  }
  
  /**
   * Determines the plugin to be tested.
   *
   * This is identified by the first #[CoverClass] attribute set on the
   * concrete test class.
   *
   * @return string
   *   The fully qualified class name of the plugin to be tested.
   */
  protected function getPluginClass() {
    $coversClass = $this->valueObjectForEvents()
      ->metadata()
      ->isCoversClass()
      ->isClassLevel()
      ->asArray();
    if (isset($coversClass[0])) {
      return $coversClass[0]->className();
    }
    $covers = $this->valueObjectForEvents()
      ->metadata()
      ->isCovers()
      ->isClassLevel()
      ->asArray();
    if (isset($covers[0])) {
      return $covers[0]->target();
    }
    $this->fail('No plugin class was specified');
  }
  
  /**
   * Instantiates the source plugin under test.
   *
   * @param array $configuration
   *   The source plugin configuration.
   *
   * @return \Drupal\migrate\Plugin\MigrateSourceInterface|object
   *   The fully configured source plugin.
   */
  protected function getPlugin(array $configuration) {
    // Only create the plugin once per test.
    if ($this->plugin) {
      return $this->plugin;
    }
    $class = ltrim($this->getPluginClass(), '\\');
    /** @var \Drupal\migrate\Plugin\MigratePluginManager $plugin_manager */
    $plugin_manager = $this->container
      ->get('plugin.manager.migrate.source');
    foreach ($plugin_manager->getDefinitions() as $id => $definition) {
      if (ltrim($definition['class'], '\\') == $class) {
        $this->plugin = $plugin_manager->createInstance($id, $configuration, $this->migration
          ->reveal());
        $this->migration
          ->getSourcePlugin()
          ->willReturn($this->plugin);
        return $this->plugin;
      }
    }
    $this->fail('No plugin found for class ' . $class);
  }
  
  /**
   * Tests the source plugin against a particular data set.
   *
   * @param array $source_data
   *   The source data that the source plugin will read.
   * @param array $expected_data
   *   The result rows the source plugin is expected to return.
   * @param mixed $expected_count
   *   (optional) How many rows the source plugin is expected to return.
   *   Defaults to count($expected_data). If set to a non-null, non-numeric
   *   value (like FALSE or 'nope'), the source plugin will not be counted.
   * @param array $configuration
   *   (optional) Configuration for the source plugin.
   * @param mixed $high_water
   *   (optional) The value of the high water field.
   *
   * @see ::migratePrepareRow()
   */
  public function testSource(array $source_data, array $expected_data, $expected_count = NULL, array $configuration = [], $high_water = NULL) : void {
    $plugin = $this->getPlugin($configuration);
    $clone_plugin = clone $plugin;
    // All source plugins must define IDs.
    $this->assertNotEmpty($plugin->getIds());
    // If there is a high water mark, set it in the high water storage.
    if (isset($high_water)) {
      $this->container
        ->get('keyvalue')
        ->get('migrate:high_water')
        ->set($this->migration
        ->reveal()
        ->id(), $high_water);
    }
    if (is_null($expected_count)) {
      $expected_count = count($expected_data);
    }
    // If an expected count was given, assert it only if the plugin is
    // countable.
    if (is_numeric($expected_count)) {
      $this->assertInstanceOf('\\Countable', $plugin);
      $this->assertCount($expected_count, $plugin);
    }
    $i = 0;
    /** @var \Drupal\migrate\Row $row */
    foreach ($plugin as $row) {
      $this->assertInstanceOf(Row::class, $row);
      $expected = $expected_data[$i++];
      $actual = $row->getSource();
      foreach ($expected as $key => $value) {
        $this->assertArrayHasKey($key, $actual);
        $msg = sprintf("Value at 'array[%s][%s]' is not correct.", $i - 1, $key);
        if (is_array($value)) {
          ksort($value);
          ksort($actual[$key]);
          $this->assertEquals($value, $actual[$key], $msg);
        }
        else {
          $this->assertEquals((string) $value, (string) $actual[$key], $msg);
        }
      }
    }
    // False positives occur if the foreach is not entered. So, confirm the
    // foreach loop was entered if the expected count is greater than 0.
    if ($expected_count > 0) {
      $this->assertGreaterThan(0, $i);
      // Test that we can skip all rows.
      \Drupal::state()->set('migrate_skip_all_rows_test_migrate_prepare_row', TRUE);
      foreach ($clone_plugin as $row) {
        $this->fail('Row not skipped');
      }
    }
  }
  
  /**
   * Implements hook_migrate_prepare_row().
   *
   * @see ::testSource()
   */
  public function migratePrepareRow(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) : void {
    if (\Drupal::state()->get('migrate_skip_all_rows_test_migrate_prepare_row')) {
      throw new MigrateSkipRowException();
    }
  }
  
  /**
   * Provides source data for ::testSource.
   *
   * @return iterable
   *   The source data.
   */
  abstract public static function providerSource();

}