ShoppingCartTest.java

	@Test
	public void addingItemChangesBasketTotal() {
		
		List<Object[]> basket = new ArrayList<>();
		
		String productCode = "P111";
		String productDescription = "Widget (Large)";
		double price = 10.0;
		int quantity = 10;
		
		ShoppingBasket shoppingBasket = new ShoppingBasket(basket);
		shoppingBasket.addItem(productCode, productDescription, price, quantity);
		
		double total = shoppingBasket.getBasket().stream()
				.mapToDouble(i -> (double)i[PRICE] * (int)i[QUANTITY])
				.sum();
		
		assertEquals(100.0, total , 0.0);
	}