Check whether views got enabled.
public function testFrontpageUpgrade() {
$this
->assertTrue($this
->performUpgrade(), 'The upgrade was completed successfully.');
$this
->assertTrue($this->container
->get('module_handler')
->moduleExists('views'), 'Views is enabled after the upgrade.');
$views = $this->container
->get('plugin.manager.entity')
->getStorageController('view')
->load(array(
'frontpage',
));
$view = reset($views);
$this
->assertTrue($view
->status(), 'The frontpage view is enabled after the upgrade.');
}