--TEST-- MongoDB\Driver\Manager::__construct() with duplicate read preference option --FILE-- <?php $manager = new MongoDB\Driver\Manager(null, ['readPreference' => 'primary', 'readpreference' => 'secondary']); echo $manager->getReadPreference()->getMode(), "\n"; ?> ===DONE=== <?php exit(0); ?> --EXPECT-- 2 ===DONE===