class MigrateTestCase

abstract class MigrateTestCase extends UnitTestCase {
    
    /**
     * An array of migration configuration values.
     *
     * @var array
     */
    protected $migrationConfiguration = [];
    
    /**
     * The migration ID map.
     *
     * @var \Drupal\migrate\Plugin\MigrateIdMapInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $idMap;
    
    /**
     * Local store for mocking setStatus()/getStatus().
     *
     * @var int
     */
    protected $migrationStatus = MigrationInterface::STATUS_IDLE;
    
    /**
     * Retrieves a mocked migration.
     *
     * @param \Drupal\migrate\Plugin\MigrateIdMapInterface|\PHPUnit\Framework\MockObject\MockObject|null $id_map
     *   An ID map plugin to use, or NULL for using a mocked one. Optional,
     *   defaults to NULL.
     *
     * @return \Drupal\migrate\Plugin\MigrationInterface|\PHPUnit\Framework\MockObject\MockObject
     *   The mocked migration.
     */
    protected function getMigration($id_map = NULL) {
        $this->migrationConfiguration += [
            'migrationClass' => 'Drupal\\migrate\\Plugin\\Migration',
        ];
        $this->idMap = $id_map;
        if (is_null($id_map)) {
            $this->idMap = $this->createMock(MigrateIdMapInterface::class);
            $this->idMap
                ->method('getQualifiedMapTableName')
                ->willReturn('test_map');
        }
        $migration = $this->getMockBuilder($this->migrationConfiguration['migrationClass'])
            ->disableOriginalConstructor()
            ->getMock();
        $migration->method('checkRequirements')
            ->willReturn(TRUE);
        $migration->method('getIdMap')
            ->willReturn($this->idMap);
        // We need the state to be toggled throughout the test so we store the value
        // on the test class and use a return callback.
        $migration->expects($this->any())
            ->method('getStatus')
            ->willReturnCallback(function () {
            return $this->migrationStatus;
        });
        $migration->expects($this->any())
            ->method('setStatus')
            ->willReturnCallback(function ($status) {
            $this->migrationStatus = $status;
        });
        $migration->method('getMigrationDependencies')
            ->willReturn([
            'required' => [],
            'optional' => [],
        ]);
        $configuration =& $this->migrationConfiguration;
        $migration->method('set')
            ->willReturnCallback(function ($argument, $value) use (&$configuration) {
            $configuration[$argument] = $value;
        });
        $migration->method('id')
            ->willReturn($configuration['id']);
        return $migration;
    }
    
    /**
     * Gets an SQLite database connection object for use in tests.
     *
     * @param array $database_contents
     *   The database contents faked as an array. Each key is a table name, each
     *   value is a list of table rows, an associative array of field => value.
     * @param array $connection_options
     *   (optional) Options for the database connection. Defaults to an empty
     *   array.
     *
     * @return \Drupal\sqlite\Driver\Database\sqlite\Connection
     *   The database connection.
     */
    protected function getDatabase(array $database_contents, $connection_options = []) {
        if (extension_loaded('pdo_sqlite')) {
            $connection_options['database'] = ':memory:';
            $pdo = Connection::open($connection_options);
            $connection = new Connection($pdo, $connection_options);
        }
        else {
            $this->markTestSkipped('The pdo_sqlite extension is not available.');
        }
        // Initialize the DIC with a fake module handler for alterable queries.
        $container = new ContainerBuilder();
        $container->set('module_handler', $this->createMock('\\Drupal\\Core\\Extension\\ModuleHandlerInterface'));
        \Drupal::setContainer($container);
        // Create the tables and load them up with data, skipping empty ones.
        foreach (array_filter($database_contents) as $table => $rows) {
            $pilot_row = reset($rows);
            $connection->schema()
                ->createTable($table, $this->createSchemaFromRow($pilot_row));
            $insert = $connection->insert($table)
                ->fields(array_keys($pilot_row));
            array_walk($rows, [
                $insert,
                'values',
            ]);
            $insert->execute();
        }
        return $connection;
    }
    
    /**
     * Generates a table schema from a row.
     *
     * @param array $row
     *   The reference row on which to base the schema.
     *
     * @return array
     *   The Schema API-ready table schema.
     */
    protected function createSchemaFromRow(array $row) {
        // SQLite uses loose ("affinity") typing, so it is OK for every column to be
        // a text field.
        $fields = array_map(function () {
            return [
                'type' => 'text',
            ];
        }, $row);
        return [
            'fields' => $fields,
        ];
    }
    
    /**
     * Tests a query.
     *
     * @param array|\Traversable $iter
     *   The countable. foreach-able actual results if a query is being run.
     * @param array $expected_results
     *   An array of expected results.
     */
    public function queryResultTest($iter, $expected_results) {
        $this->assertSameSize($expected_results, $iter, 'Number of results match');
        $count = 0;
        foreach ($iter as $data_row) {
            $expected_row = $expected_results[$count];
            $count++;
            foreach ($expected_row as $key => $expected_value) {
                $this->retrievalAssertHelper($expected_value, $this->getValue($data_row, $key), sprintf('Value matches for key "%s"', $key));
            }
        }
        $this->assertSame(count($expected_results), $count);
    }
    
    /**
     * Gets the value on a row for a given key.
     *
     * @param array $row
     *   The row information.
     * @param string $key
     *   The key identifier.
     *
     * @return mixed
     *   The value on a row for a given key.
     */
    protected function getValue($row, $key) {
        return $row[$key];
    }
    
    /**
     * Asserts tested values during test retrieval.
     *
     * @param mixed $expected_value
     *   The incoming expected value to test.
     * @param mixed $actual_value
     *   The incoming value itself.
     * @param string $message
     *   The tested result as a formatted string.
     */
    protected function retrievalAssertHelper($expected_value, $actual_value, $message) {
        if (is_array($expected_value)) {
            // If the expected and actual values are empty, no need to array compare.
            if (empty($expected_value && $actual_value)) {
                return;
            }
            $this->assertEquals($expected_value, $actual_value, $message);
        }
        else {
            $this->assertSame((string) $expected_value, (string) $actual_value, $message);
        }
    }

}