Rename ambiguous variables and methods for clarity

java/pom.xml

@@ -45,8 +45,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.8.0</version>
                 <configuration>
-                    <source>22</source>
-                    <target>22</target>
+                    <source>17</source>
+                    <target>17</target>
                 </configuration>
             </plugin>
         </plugins>

java/src/main/java/dojo/supermarket/model/ShoppingCart.java

@@ -33,39 +33,39 @@ public void addItemQuantity(Product product, double quantity) {
     }
 
     void handleOffers(Receipt receipt, Map<Product, Offer> offers, SupermarketCatalog catalog) {
-        for (Product p: productQuantities().keySet()) {
-            double quantity = productQuantities.get(p);
-            if (offers.containsKey(p)) {
-                Offer offer = offers.get(p);
-                double unitPrice = catalog.getUnitPrice(p);
+        for (Product product: productQuantities().keySet()) {
+            double quantity = productQuantities.get(product);
+            if (offers.containsKey(product)) {
+                Offer offer = offers.get(product);
+                double unitPrice = catalog.getUnitPrice(product);
                 int quantityAsInt = (int) quantity;
                 Discount discount = null;
-                int x = 1;
+                int itemsPerDeal = 1;
                 if (offer.offerType == SpecialOfferType.THREE_FOR_TWO) {
-                    x = 3;
+                    itemsPerDeal = 3;
 
                 } else if (offer.offerType == SpecialOfferType.TWO_FOR_AMOUNT) {
-                    x = 2;
+                    itemsPerDeal = 2;
                     if (quantityAsInt >= 2) {
-                        double total = offer.argument * (quantityAsInt / x) + quantityAsInt % 2 * unitPrice;
-                        double discountN = unitPrice * quantity - total;
-                        discount = new Discount(p, "2 for " + offer.argument, -discountN);
+                        double total = offer.argument * (quantityAsInt / itemsPerDeal) + quantityAsInt % 2 * unitPrice;
+                        double discountAmount = unitPrice * quantity - total;
+                        discount = new Discount(product, "2 for " + offer.argument, -discountAmount);
                     }
 
                 } if (offer.offerType == SpecialOfferType.FIVE_FOR_AMOUNT) {
-                    x = 5;
+                    itemsPerDeal = 5;
                 }
-                int numberOfXs = quantityAsInt / x;
+                int numberOfCompleteDeals = quantityAsInt / itemsPerDeal;
                 if (offer.offerType == SpecialOfferType.THREE_FOR_TWO && quantityAsInt > 2) {
-                    double discountAmount = quantity * unitPrice - ((numberOfXs * 2 * unitPrice) + quantityAsInt % 3 * unitPrice);
-                    discount = new Discount(p, "3 for 2", -discountAmount);
+                    double discountAmount = quantity * unitPrice - ((numberOfCompleteDeals * 2 * unitPrice) + quantityAsInt % 3 * unitPrice);
+                    discount = new Discount(product, "3 for 2", -discountAmount);
                 }
                 if (offer.offerType == SpecialOfferType.TEN_PERCENT_DISCOUNT) {
-                    discount = new Discount(p, offer.argument + "% off", -quantity * unitPrice * offer.argument / 100.0);
+                    discount = new Discount(product, offer.argument + "% off", -quantity * unitPrice * offer.argument / 100.0);
                 }
                 if (offer.offerType == SpecialOfferType.FIVE_FOR_AMOUNT && quantityAsInt >= 5) {
-                    double discountTotal = unitPrice * quantity - (offer.argument * numberOfXs + quantityAsInt % 5 * unitPrice);
-                    discount = new Discount(p, x + " for " + offer.argument, -discountTotal);
+                    double totalDiscountAmount = unitPrice * quantity - (offer.argument * numberOfCompleteDeals + quantityAsInt % 5 * unitPrice);
+                    discount = new Discount(product, itemsPerDeal + " for " + offer.argument, -totalDiscountAmount);
                 }
                 if (discount != null)
                     receipt.addDiscount(discount);

java/src/main/java/dojo/supermarket/model/Teller.java

@@ -17,17 +17,17 @@ public void addSpecialOffer(SpecialOfferType offerType, Product product, double
         offers.put(product, new Offer(offerType, product, argument));
     }
 
-    public Receipt checksOutArticlesFrom(ShoppingCart theCart) {
+    public Receipt checkoutCart(ShoppingCart cart) {
         Receipt receipt = new Receipt();
-        List<ProductQuantity> productQuantities = theCart.getItems();
-        for (ProductQuantity pq: productQuantities) {
-            Product p = pq.getProduct();
-            double quantity = pq.getQuantity();
-            double unitPrice = catalog.getUnitPrice(p);
+        List<ProductQuantity> productQuantities = cart.getItems();
+        for (ProductQuantity productQuantity: productQuantities) {
+            Product product = productQuantity.getProduct();
+            double quantity = productQuantity.getQuantity();
+            double unitPrice = catalog.getUnitPrice(product);
             double price = quantity * unitPrice;
-            receipt.addProduct(p, quantity, unitPrice, price);
+            receipt.addProduct(product, quantity, unitPrice, price);
         }
-        theCart.handleOffers(receipt, offers, catalog);
+        cart.handleOffers(receipt, offers, catalog);
 
         return receipt;
     }

java/src/test/java/dojo/supermarket/model/SupermarketTest.java

@@ -27,7 +27,7 @@ void tenPercentDiscount() {
         cart.addItemQuantity(apples, 2.5);
 
         // ACT
-        Receipt receipt = teller.checksOutArticlesFrom(cart);
+        Receipt receipt = teller.checkoutCart(cart);
 
         // ASSERT
         assertEquals(4.975, receipt.getTotalPrice(), 0.01);

python/receipt_printer.py

@@ -30,8 +30,7 @@ def print_receipt_item(self, item):
     def format_line_with_whitespace(self, name, value):
         line = name
         whitespace_size = self.columns - len(name) - len(value)
-        for i in range(whitespace_size):
-            line += " "
+        line += " " * whitespace_size
         line += value
         line += "\n"
         return line

python/shopping_cart.py

@@ -28,41 +28,41 @@ def add_item_quantity(self, product, quantity):
             self._product_quantities[product] = quantity
 
     def handle_offers(self, receipt, offers, catalog):
-        for p in self._product_quantities.keys():
-            quantity = self._product_quantities[p]
-            if p in offers.keys():
-                offer = offers[p]
-                unit_price = catalog.unit_price(p)
+        for product in self._product_quantities.keys():
+            quantity = self._product_quantities[product]
+            if product in offers.keys():
+                offer = offers[product]
+                unit_price = catalog.unit_price(product)
                 quantity_as_int = int(quantity)
                 discount = None
-                x = 1
+                items_per_deal = 1
                 if offer.offer_type == SpecialOfferType.THREE_FOR_TWO:
-                    x = 3
+                    items_per_deal = 3
 
                 elif offer.offer_type == SpecialOfferType.TWO_FOR_AMOUNT:
-                    x = 2
+                    items_per_deal = 2
                     if quantity_as_int >= 2:
-                        total = offer.argument * (quantity_as_int / x) + quantity_as_int % 2 * unit_price
-                        discount_n = unit_price * quantity - total
-                        discount = Discount(p, "2 for " + str(offer.argument), -discount_n)
+                        total = offer.argument * (quantity_as_int / items_per_deal) + quantity_as_int % 2 * unit_price
+                        discount_amount = unit_price * quantity - total
+                        discount = Discount(product, "2 for " + str(offer.argument), -discount_amount)
 
                 if offer.offer_type == SpecialOfferType.FIVE_FOR_AMOUNT:
-                    x = 5
+                    items_per_deal = 5
 
-                number_of_x = math.floor(quantity_as_int / x)
+                number_of_complete_deals = math.floor(quantity_as_int / items_per_deal)
                 if offer.offer_type == SpecialOfferType.THREE_FOR_TWO and quantity_as_int > 2:
                     discount_amount = quantity * unit_price - (
-                                (number_of_x * 2 * unit_price) + quantity_as_int % 3 * unit_price)
-                    discount = Discount(p, "3 for 2", -discount_amount)
+                                (number_of_complete_deals * 2 * unit_price) + quantity_as_int % 3 * unit_price)
+                    discount = Discount(product, "3 for 2", -discount_amount)
 
                 if offer.offer_type == SpecialOfferType.TEN_PERCENT_DISCOUNT:
-                    discount = Discount(p, str(offer.argument) + "% off",
+                    discount = Discount(product, str(offer.argument) + "% off",
                                         -quantity * unit_price * offer.argument / 100.0)
 
                 if offer.offer_type == SpecialOfferType.FIVE_FOR_AMOUNT and quantity_as_int >= 5:
-                    discount_total = unit_price * quantity - (
-                                offer.argument * number_of_x + quantity_as_int % 5 * unit_price)
-                    discount = Discount(p, str(x) + " for " + str(offer.argument), -discount_total)
+                    total_discount_amount = unit_price * quantity - (
+                                offer.argument * number_of_complete_deals + quantity_as_int % 5 * unit_price)
+                    discount = Discount(product, str(items_per_deal) + " for " + str(offer.argument), -total_discount_amount)
 
                 if discount:
                     receipt.add_discount(discount)

python/teller.py

@@ -11,16 +11,16 @@ def __init__(self, catalog):
     def add_special_offer(self, offer_type, product, argument):
         self.offers[product] = Offer(offer_type, product, argument)
 
-    def checks_out_articles_from(self, the_cart):
+    def checkout_cart(self, cart):
         receipt = Receipt()
-        product_quantities = the_cart.items
-        for pq in product_quantities:
-            p = pq.product
-            quantity = pq.quantity
-            unit_price = self.catalog.unit_price(p)
+        product_quantities = cart.items
+        for product_quantity in product_quantities:
+            product = product_quantity.product
+            quantity = product_quantity.quantity
+            unit_price = self.catalog.unit_price(product)
             price = quantity * unit_price
-            receipt.add_product(p, quantity, unit_price, price)
+            receipt.add_product(product, quantity, unit_price, price)
 
-        the_cart.handle_offers(receipt, self.offers, self.catalog)
+        cart.handle_offers(receipt, self.offers, self.catalog)
 
         return receipt

python/tests/test_supermarket.py

@@ -20,7 +20,7 @@ def test_ten_percent_discount():
     cart = ShoppingCart()
     cart.add_item_quantity(apples, 2.5)
 
-    receipt = teller.checks_out_articles_from(cart)
+    receipt = teller.checkout_cart(cart)
 
     assert 4.975 == pytest.approx(receipt.total_price(), 0.01)
     assert [] == receipt.discounts
@@ -30,3 +30,24 @@ def test_ten_percent_discount():
     assert 1.99 == receipt_item.price
     assert 2.5 * 1.99 == pytest.approx(receipt_item.total_price, 0.01)
     assert 2.5 == receipt_item.quantity
+
+
+def test_three_for_two_offer():
+    """Test to verify the renamed variables work correctly for three-for-two offers"""
+    catalog = FakeCatalog()
+    toothbrush = Product("toothbrush", ProductUnit.EACH)
+    catalog.add_product(toothbrush, 0.99)
+
+    teller = Teller(catalog)
+    teller.add_special_offer(SpecialOfferType.THREE_FOR_TWO, toothbrush, 0)
+
+    cart = ShoppingCart()
+    cart.add_item_quantity(toothbrush, 3)
+
+    receipt = teller.checkout_cart(cart)
+
+    # Should get 3 items for the price of 2
+    expected_price = 2 * 0.99  # Pay for 2, get 1 free
+    assert expected_price == pytest.approx(receipt.total_price(), 0.01)
+    assert 1 == len(receipt.discounts)
+    assert "3 for 2" in receipt.discounts[0].description