Make sure the maintenance mode can be bypassed using hook_menu_site_status_alter().
hook_menu_site_status_alter().
function testMaintenanceModeLoginPaths() {
config('system.maintenance')
->set('enabled', 1)
->save();
$offline_message = t('@site is currently under maintenance. We should be back shortly. Thank you for your patience.', array(
'@site' => config('system.site')
->get('name'),
));
$this
->drupalGet('test-page');
$this
->assertText($offline_message);
$this
->drupalGet('menu_login_callback');
$this
->assertText('This is menu_login_callback().', 'Maintenance mode can be bypassed through hook_menu_site_status_alter().');
config('system.maintenance')
->set('enabled', 0)
->save();
}