public function testCustomerLogin() { $event = $this->getMockBuilder('Magento\\Framework\\Event\\Observer')->disableOriginalConstructor()->getMock(); /** @var $event \Magento\Framework\Event\Observer */ $this->helper->expects($this->once())->method('calculate'); $this->assertInstanceOf('Magento\\Wishlist\\Model\\Observer', $this->observer->customerLogin($event)); }