feat(tiered_pricing): 🔵 ensure that tiers are used

Author: adrianliz

exercises/graduated_tiered_prices/solutions/adrianliz/src/GraduatedTieredPricing.ts

@@ -2,19 +2,9 @@ import GraduatedTier from "./GraduatedTier";
 import Subscriptions from "./Subscriptions";
 
 export default class GraduatedTieredPricing {
-  constructor(private readonly tiers: GraduatedTier[] | null) {}
-
-  private defaultTiers(): GraduatedTier[] {
-    return [
-      new GraduatedTier(1, 2, 299),
-      new GraduatedTier(3, 10, 239),
-      new GraduatedTier(11, 25, 219),
-      new GraduatedTier(26, 50, 199),
-      new GraduatedTier(51, Number.MAX_SAFE_INTEGER, 149),
-    ];
-  }
+  constructor(private readonly tiers: GraduatedTier[]) {}
 
   priceFor(subscriptions: Subscriptions): number {
-    return subscriptions.priceFor(this.tiers || this.defaultTiers());
+    return subscriptions.priceFor(this.tiers);
   }
 }

exercises/graduated_tiered_prices/solutions/adrianliz/tests/GraduatedTieredPricing.test.ts

@@ -1,12 +1,24 @@
 import each from "jest-each";
 
+import GraduatedTier from "../src/GraduatedTier";
 import GraduatedTieredPricing from "../src/GraduatedTieredPricing";
 import NumberOfSubscriptionsNotAllowed from "../src/NumberOfSubscriptionsNotAllowed";
 import Subscriptions from "../src/Subscriptions";
 
 describe("Graduated tiered pricing should", () => {
+  const defaultTiers = (): GraduatedTier[] => {
+    return [
+      new GraduatedTier(1, 2, 299),
+      new GraduatedTier(3, 10, 239),
+      new GraduatedTier(11, 25, 219),
+      new GraduatedTier(26, 50, 199),
+      new GraduatedTier(51, Number.MAX_SAFE_INTEGER, 149),
+    ];
+  };
+
   it("throw number of subscriptions not allowed for 0 subscriptions", () => {
-    const pricing = new GraduatedTieredPricing(null);
+    const tiers = defaultTiers();
+    const pricing = new GraduatedTieredPricing(tiers);
     expect(() => pricing.priceFor(new Subscriptions(0))).toThrow(
       NumberOfSubscriptionsNotAllowed
     );
@@ -23,7 +35,8 @@ describe("Graduated tiered pricing should", () => {
   ]).it(
     "calculate the price for %i subscriptions",
     (subscriptions: number, expectedPrice: number) => {
-      const pricing = new GraduatedTieredPricing(null);
+      const tiers = defaultTiers();
+      const pricing = new GraduatedTieredPricing(tiers);
       expect(pricing.priceFor(new Subscriptions(subscriptions))).toBe(
         expectedPrice
       );