Add last tier

Author: mikybars

exercises/tiered_pricing/solutions/mperezi/src/main/java/tv/codely/checkout/TieredPricing.java

@@ -8,12 +8,17 @@ private enum Tier {
     FIRST(299.0, 1, 2),
     SECOND(239.0, 3, 10),
     THIRD(219.0, 11, 25),
-    FOURTH(199.0, 26, 50);
+    FOURTH(199.0, 26, 50),
+    LAST(149.0, 51);
 
     final double unitPrice;
     final int startRange;
     final int endRange;
 
+    Tier(double unitPrice, int startRange) {
+      this(unitPrice, startRange, -1);
+    }
+
     Tier(double unitPrice, int startRange, int endRange) {
       this.unitPrice = unitPrice;
       this.startRange = startRange;
@@ -24,7 +29,7 @@ static Tier of(int subscriptions) {
       return Arrays.stream(values())
                    .filter(tier -> subscriptions >= tier.startRange && subscriptions <= tier.endRange)
                    .findFirst()
-                   .orElseThrow(() -> new IllegalArgumentException("Invalid number of subscriptions: " + subscriptions));
+                   .orElse(LAST);
     }
   }
 

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

@@ -3,6 +3,7 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.provider.ValueSource;
 
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -50,6 +51,14 @@ void returnTotalPriceForFourthTier(int subscriptions) {
     assertThat(totalPrice).isEqualTo(subscriptions * 199.0);
   }
 
+  @ParameterizedTest
+  @ValueSource(ints = {51, 1000})
+  void returnTotalPriceForLastTier(int subscriptions) {
+    double totalPrice = tieredPricing.totalPrice(subscriptions);
+
+    assertThat(totalPrice).isEqualTo(subscriptions * 149.0);
+  }
+
   private static Stream<Integer> rangeFirstTier() {
     return IntStream.rangeClosed(1, 2).boxed();
   }