feat(graduated-tiered-pricing): [tpp] 🔵 preparatory refactoring: wrap subscriptions

Author: santakadev

exercises/graduated_tiered_prices/solutions/codely_triangulation-with-tpp/src/GraduatedTieredPricing.ts

@@ -1,7 +1,8 @@
+import { SubscriptionsBeingPurchased } from "./SubscriptionsBeingPurchased";
 import { Tier } from "./Tier";
 
 export class GraduatedTieredPricing {
-  for(subscriptions: number): number {
+  for(subscriptions: SubscriptionsBeingPurchased): number {
     const tiers = [
       new Tier(1, 2, 299),
       new Tier(3, 10, 239),

exercises/graduated_tiered_prices/solutions/codely_triangulation-with-tpp/src/SubscriptionsBeingPurchased.ts

@@ -0,0 +1,3 @@
+export class SubscriptionsBeingPurchased {
+  constructor(public value: number) {}
+}

exercises/graduated_tiered_prices/solutions/codely_triangulation-with-tpp/src/Tier.ts

@@ -1,3 +1,5 @@
+import { SubscriptionsBeingPurchased } from "./SubscriptionsBeingPurchased";
+
 export class Tier {
   constructor(
     public readonly from: number,
@@ -13,15 +15,15 @@ export class Tier {
     return this.size() * this.price;
   }
 
-  totalFor(subscriptions: number): number {
-    if (subscriptions >= this.to) {
+  totalFor(subscriptions: SubscriptionsBeingPurchased): number {
+    if (subscriptions.value >= this.to) {
       return this.fullTierTotal();
     }
 
-    if (subscriptions < this.from) {
+    if (subscriptions.value < this.from) {
       return 0;
     }
 
-    return (subscriptions - this.from + 1) * this.price;
+    return (subscriptions.value - this.from + 1) * this.price;
   }
 }

exercises/graduated_tiered_prices/solutions/codely_triangulation-with-tpp/tests/GraduatedTieredPricing.test.ts

@@ -1,66 +1,67 @@
 import { GraduatedTieredPricing } from "../src/GraduatedTieredPricing";
+import { SubscriptionsBeingPurchased } from "../src/SubscriptionsBeingPurchased";
 
 describe("Graduated tiered pricing should", () => {
   test("return 299€ for 1 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(1);
+    const total = pricing.for(new SubscriptionsBeingPurchased(1));
 
     expect(total).toBe(299);
   });
 
   test("return 598€ for 2 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(2);
+    const total = pricing.for(new SubscriptionsBeingPurchased(2));
 
     expect(total).toBe(598);
   });
 
   test("return 837€ for 3 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(3);
+    const total = pricing.for(new SubscriptionsBeingPurchased(3));
 
     expect(total).toBe(837);
   });
 
   test("return 1076€ for 4 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(4);
+    const total = pricing.for(new SubscriptionsBeingPurchased(4));
 
     expect(total).toBe(1076);
   });
 
   test("return 1315€ for 5 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(5);
+    const total = pricing.for(new SubscriptionsBeingPurchased(5));
 
     expect(total).toBe(1315);
   });
 
   test("return 2729€ for 11 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(11);
+    const total = pricing.for(new SubscriptionsBeingPurchased(11));
 
     expect(total).toBe(2729);
   });
 
   test("return 2948€ for 12 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(12);
+    const total = pricing.for(new SubscriptionsBeingPurchased(12));
 
     expect(total).toBe(2948);
   });
 
   test("return 5994€ for 26 subscription", async () => {
     const pricing = new GraduatedTieredPricing();
 
-    const total = pricing.for(26);
+    const total = pricing.for(new SubscriptionsBeingPurchased(26));
 
     expect(total).toBe(5994);
   });