public function testDiscountTotalPrice() { $item = new Item('RedBull', '240', '2011-07', '50'); $discount_number = 24; $discount_percentage = 20; $item->setDiscounter($discount_number, $discount_percentage); $number = 40; $this->cart->addToCart($item, $number); $expected = $item->getPrice() * $number * $discount_percentage * 0.01; $this->assertEquals($expected, $this->cart->getTotalPrice()); }