class MigrateSourceTestBase

abstract class MigrateSourceTestBase extends KernelTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'migrate',
        'migrate_skip_all_rows_test',
    ];
    
    /**
     * 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;
    
    /**
     * The data provider.
     *
     * @see \Drupal\Tests\migrate\Kernel\MigrateSourceTestBase::testSource
     *
     * @return array
     *   Array of data sets to test, each of which is a numerically indexed array
     *   with the following elements:
     *   - An array of source data, which can be optionally processed and set up
     *     by subclasses.
     *   - An array of expected result rows.
     *   - (optional) The number of result rows the plugin under test is expected
     *     to return. If this is not a numeric value, the plugin will not be
     *     counted.
     *   - (optional) Array of configuration options for the plugin under test.
     */
    public abstract function providerSource();
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() {
        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 by reading the class @covers annotation.
     *
     * @return string
     */
    protected function getPluginClass() {
        $annotations = Test::parseTestMethodAnnotations(static::class, $this->getName());
        if (isset($annotations['class']['covers'])) {
            return $annotations['class']['covers'][0];
        }
        else {
            $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.
     *
     * @dataProvider providerSource
     */
    public function testSource(array $source_data, array $expected_data, $expected_count = NULL, array $configuration = [], $high_water = NULL) {
        $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');
            }
        }
    }

}