Sets up unit test environment.
Unlike Drupal\simpletest\WebTestBase::setUp(), UnitTestBase::setUp() does not install modules because tests are performed without accessing the database. Any required files must be explicitly included by the child class setUp() method.
Overrides StorageTestBase::setUp
protected function setUp() {
parent::setUp();
module_load_install('system');
$schema = system_schema();
db_create_table('key_value', $schema['key_value']);
$this->container
->register('database', 'Drupal\\Core\\Database\\Connection')
->setFactoryClass('Drupal\\Core\\Database\\Database')
->setFactoryMethod('getConnection')
->addArgument('default');
$this->container
->register('keyvalue.database', 'Drupal\\Core\\KeyValueStore\\KeyValueDatabaseFactory')
->addArgument(new Reference('database'));
global $conf;
$conf['keyvalue_default'] = 'keyvalue.database';
}