We're using a few different conventions for namespaces in the tests directory. Here are a few,
FileImporter\Tests\Services\Wikitext FileImporter\Services\Test FileImporter\Tests\Operations FileImporter\Operations\Test
Let's choose one consistent pattern, perhaps FileImporter\Tests\…, so that classes can be addressed using PSR-4 and to make it clear how to choose namespaces for additional classes in the future.