feat(tiered_pricing): 🔵 refactoring extract enum

Author: oflorez1381

exercises/tiered_pricing/solutions/oflorez/src/main/java/tv/codely/checkout/Tier.java

@@ -0,0 +1,43 @@
+package tv.codely.checkout;
+
+
+public enum Tier {
+
+    FIRST(1,2,299),
+    SECOND(3,10,239),
+    THIRD(11,25,219);
+
+    private final int lowerLimit;
+    private final int upperLimit;
+    private final int unitPrice;
+
+    Tier(int lowerLimit, int upperLimit, int unitPrice) {
+        this.lowerLimit = lowerLimit;
+        this.upperLimit = upperLimit;
+        this.unitPrice = unitPrice;
+    }
+
+    public int getLowerLimit() {
+        return lowerLimit;
+    }
+
+    public int getUpperLimit() {
+        return upperLimit;
+    }
+
+    public int getUnitPrice() {
+        return unitPrice;
+    }
+
+    public static int getTotalPrice(int subscriptions) {
+        var found = FIRST;
+        for (Tier tier : values()) {
+            if ( subscriptions >= tier.lowerLimit && subscriptions <= tier.upperLimit) {
+                found = tier;
+                break;
+            }
+        }
+
+        return subscriptions * found.unitPrice;
+    }
+}

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

@@ -2,25 +2,7 @@
 
 public class TieredPricing {
 
-    public static final int FIRST_RANGE_UNIT_PRICE = 299;
-    public static final int FIRST_RANGE_LOWER_LIMIT = 1;
-    public static final int FIRST_RANGE_UPPER_LIMIT = 2;
-
-    public static final int SECOND_RANGE_UNIT_PRICE = 239;
-    public static final int SECOND_RANGE_LOWER_LIMIT = 3;
-    public static final int SECOND_RANGE_UPPER_LIMIT = 10;
-
-    public static final int THIRD_RANGE_UNIT_PRICE = 219;
-    public static final int THIRD_RANGE_LOWER_LIMIT = 11;
-    public static final int THIRD_RANGE_UPPER_LIMIT = 25;
-
     public int calculateTotalPrice(int amount_subscriptions) {
-        if (amount_subscriptions >= FIRST_RANGE_LOWER_LIMIT && amount_subscriptions<= FIRST_RANGE_UPPER_LIMIT) return amount_subscriptions * FIRST_RANGE_UNIT_PRICE;
-
-        if (amount_subscriptions >= SECOND_RANGE_LOWER_LIMIT && amount_subscriptions<= SECOND_RANGE_UPPER_LIMIT) return amount_subscriptions * SECOND_RANGE_UNIT_PRICE;
-
-        if (amount_subscriptions >= THIRD_RANGE_LOWER_LIMIT && amount_subscriptions<= THIRD_RANGE_UPPER_LIMIT) return amount_subscriptions * THIRD_RANGE_UNIT_PRICE;
-
-        return 0;
+        return Tier.getTotalPrice(amount_subscriptions);
     }
 }

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

@@ -5,33 +5,35 @@
 import java.util.stream.IntStream;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static tv.codely.checkout.TieredPricing.*;
 
 public class TieredPricingShould {
 
     @Test
-	void calculate_total_value_for_first_pricing_range() {
+	void calculate_total_value_for_first_pricing_tier() {
         var pricing = new TieredPricing();
-        var subscription = retrieveSubscriptionGivenRange(FIRST_RANGE_LOWER_LIMIT, FIRST_RANGE_UPPER_LIMIT);
-        assertEquals(calculateTotalPriceExpected(FIRST_RANGE_UNIT_PRICE, subscription), pricing.calculateTotalPrice(subscription));
+        var tier = Tier.FIRST;
+        var subscription = retrieveSubscriptionGivenTier(tier);
+        assertEquals(calculateTotalPriceExpected(tier.getUnitPrice(), subscription), pricing.calculateTotalPrice(subscription));
 	}
 
     @Test
-    void calculate_total_value_for_second_pricing_range() {
+    void calculate_total_value_for_second_pricing_tier() {
         var pricing = new TieredPricing();
-        var subscription = retrieveSubscriptionGivenRange(SECOND_RANGE_LOWER_LIMIT,SECOND_RANGE_UPPER_LIMIT);
-        assertEquals(calculateTotalPriceExpected(SECOND_RANGE_UNIT_PRICE, subscription), pricing.calculateTotalPrice(subscription));
+        var tier = Tier.SECOND;
+        var subscription = retrieveSubscriptionGivenTier(tier);
+        assertEquals(calculateTotalPriceExpected(tier.getUnitPrice(), subscription), pricing.calculateTotalPrice(subscription));
     }
 
     @Test
-    void calculate_total_value_for_third_pricing_range() {
+    void calculate_total_value_for_third_pricing_tier() {
         var pricing = new TieredPricing();
-        var subscription = retrieveSubscriptionGivenRange(THIRD_RANGE_LOWER_LIMIT,THIRD_RANGE_UPPER_LIMIT);
-        assertEquals(calculateTotalPriceExpected(THIRD_RANGE_UNIT_PRICE, subscription), pricing.calculateTotalPrice(subscription));
+        var tier = Tier.THIRD;
+        var subscription = retrieveSubscriptionGivenTier(tier);
+        assertEquals(calculateTotalPriceExpected(tier.getUnitPrice(), subscription), pricing.calculateTotalPrice(subscription));
     }
 
-    private int retrieveSubscriptionGivenRange(int lowerLimit, int upperLimit) {
-        return IntStream.rangeClosed(lowerLimit, upperLimit).findAny().getAsInt();
+    private int retrieveSubscriptionGivenTier(Tier tier) {
+        return IntStream.rangeClosed(tier.getLowerLimit(), tier.getUpperLimit()).findAny().getAsInt();
     }
 
     private int calculateTotalPriceExpected(int unitPrice, int subscription) {