public function testInvalidEnvVariableConfigDirThrowsException()
{
// I used a random hash to ensure this test directory is always invalid
$invalidDir = __DIR__ . '/e9826ad19cbc4f5bf20c0913ffcd2ce6';
putenv('SIMPLESAMLPHP_CONFIG_DIR=' . $invalidDir);
$this->setExpectedException('InvalidArgumentException', 'Config directory specified by environment variable SIMPLESAMLPHP_CONFIG_DIR is not a directory. ' . 'Given: "' . $invalidDir . '"');
Config::getConfigDir();
}