feat: add SubscriptionPrice and SubscriptionRange concepts

PriceRange constructor parallel change

Author: adrianliz

exercises/tiered_pricing/solutions/adrianliz/java/src/main/java/tv/codely/checkout/PriceRange.java

@@ -13,6 +13,12 @@ public PriceRange(int numberOfSubscriptionsFrom, int numberOfSubscriptionsTo,
         this.unitPrice = unitPrice;
     }
 
+    public PriceRange(final SubscriptionRange range,
+        final SubscriptionPrice price) {
+        this(range.numberOfSubscriptionsFrom(), range.numberOfSubscriptionsTo(),
+            price.price());
+    }
+
     public boolean isInRange(int numberOfSubscriptions) {
         return numberOfSubscriptions >= numberOfSubscriptionsFrom
             && numberOfSubscriptions <= numberOfSubscriptionsTo;

exercises/tiered_pricing/solutions/adrianliz/java/src/main/java/tv/codely/checkout/SubscriptionPrice.java

@@ -0,0 +1,14 @@
+package tv.codely.checkout;
+
+public final class SubscriptionPrice {
+
+    private final double price;
+
+    public SubscriptionPrice(double price) {
+        this.price = price;
+    }
+
+    public double price() {
+        return price;
+    }
+}

exercises/tiered_pricing/solutions/adrianliz/java/src/main/java/tv/codely/checkout/SubscriptionRange.java

@@ -0,0 +1,25 @@
+package tv.codely.checkout;
+
+public final class SubscriptionRange {
+
+    private final int numberOfSubscriptionsFrom;
+    private final int numberOfSubscriptionsTo;
+
+    public SubscriptionRange(int numberOfSubscriptionsFrom, int numberOfSubscriptionsTo) {
+        this.numberOfSubscriptionsFrom = numberOfSubscriptionsFrom;
+        this.numberOfSubscriptionsTo = numberOfSubscriptionsTo;
+    }
+
+    public boolean isSuitableFor(int numberOfSubscriptions) {
+        return numberOfSubscriptions >= numberOfSubscriptionsFrom
+            && numberOfSubscriptions <= numberOfSubscriptionsTo;
+    }
+
+    public int numberOfSubscriptionsFrom() {
+        return numberOfSubscriptionsFrom;
+    }
+
+    public int numberOfSubscriptionsTo() {
+        return numberOfSubscriptionsTo;
+    }
+}

exercises/tiered_pricing/solutions/adrianliz/java/src/test/java/tv/codely/checkout/TieredPricingShould.java

@@ -17,11 +17,11 @@ void unit_test_example() {
     void return_total_price_based_on_number_of_subscriptions() {
         final var priceRanges =
             List.of(
-                new PriceRange(1, 2, 299),
-                new PriceRange(3, 10, 239),
-                new PriceRange(11, 25, 219),
-                new PriceRange(26, 50, 199),
-                new PriceRange(51, 100, 149));
+                new PriceRange(new SubscriptionRange(1, 2), new SubscriptionPrice(299)),
+                new PriceRange(new SubscriptionRange(3, 10), new SubscriptionPrice(239)),
+                new PriceRange(new SubscriptionRange(11, 25), new SubscriptionPrice(219)),
+                new PriceRange(new SubscriptionRange(26, 50), new SubscriptionPrice(199)),
+                new PriceRange(new SubscriptionRange(51, 100), new SubscriptionPrice(149)));
         final var tieredPricing = new TieredPricing(priceRanges);
         final var expectedPrice = priceRanges.get(1).unitPrice() * 3;