Refactored existing code , added necessary unit tests and added new Dafalgan "feature"

index.js

@@ -5,7 +5,8 @@ const drugs = [
   new Drug("Doliprane", 20, 30),
   new Drug("Herbal Tea", 10, 5),
   new Drug("Fervex", 5, 40),
-  new Drug("Magic Pill", 15, 40)
+  new Drug("Magic Pill", 15, 40),
+  new Drug("Dafalgan", 20, 25)
 ];
 const trial = new Pharmacy(drugs);
 

pharmacy.js

@@ -10,56 +10,48 @@ export class Pharmacy {
   constructor(drugs = []) {
     this.drugs = drugs;
   }
+
+  decreaseBenefit(drug) {
+    drug.benefit = drug.benefit - 1;
+  }
+
+  increaseBenefit(drug) {
+    drug.benefit = drug.benefit + 1;
+  }
+
+  decreaseExpiresIn(drug) {
+    drug.expiresIn = drug.expiresIn - 1;
+  }
+
   updateBenefitValue() {
-    for (var i = 0; i < this.drugs.length; i++) {
-      if (
-        this.drugs[i].name != "Herbal Tea" &&
-        this.drugs[i].name != "Fervex"
-      ) {
-        if (this.drugs[i].benefit > 0) {
-          if (this.drugs[i].name != "Magic Pill") {
-            this.drugs[i].benefit = this.drugs[i].benefit - 1;
-          }
-        }
-      } else {
-        if (this.drugs[i].benefit < 50) {
-          this.drugs[i].benefit = this.drugs[i].benefit + 1;
-          if (this.drugs[i].name == "Fervex") {
-            if (this.drugs[i].expiresIn < 11) {
-              if (this.drugs[i].benefit < 50) {
-                this.drugs[i].benefit = this.drugs[i].benefit + 1;
-              }
-            }
-            if (this.drugs[i].expiresIn < 6) {
-              if (this.drugs[i].benefit < 50) {
-                this.drugs[i].benefit = this.drugs[i].benefit + 1;
-              }
-            }
-          }
-        }
-      }
-      if (this.drugs[i].name != "Magic Pill") {
-        this.drugs[i].expiresIn = this.drugs[i].expiresIn - 1;
-      }
-      if (this.drugs[i].expiresIn < 0) {
-        if (this.drugs[i].name != "Herbal Tea") {
-          if (this.drugs[i].name != "Fervex") {
-            if (this.drugs[i].benefit > 0) {
-              if (this.drugs[i].name != "Magic Pill") {
-                this.drugs[i].benefit = this.drugs[i].benefit - 1;
-              }
-            }
-          } else {
-            this.drugs[i].benefit =
-              this.drugs[i].benefit - this.drugs[i].benefit;
-          }
-        } else {
-          if (this.drugs[i].benefit < 50) {
-            this.drugs[i].benefit = this.drugs[i].benefit + 1;
+    this.drugs.forEach(drug => {
+      switch (drug.name) {
+        case "Herbal Tea":
+          this.decreaseExpiresIn(drug);
+          if (drug.benefit < 50) this.increaseBenefit(drug);
+          if (drug.expiresIn < 0 && drug.benefit < 50)
+            this.increaseBenefit(drug);
+          break;
+        case "Fervex":
+          this.decreaseExpiresIn(drug);
+          if (drug.benefit < 50) this.increaseBenefit(drug);
+          if (drug.expiresIn < 11 && drug.benefit < 50)
+            this.increaseBenefit(drug);
+          if (drug.expiresIn < 6 && drug.benefit < 50)
+            this.increaseBenefit(drug);
+          if (drug.expiresIn < 0) drug.benefit = drug.benefit - drug.benefit;
+          break;
+        case "Magic Pill":
+          drug.benefit = drug.benefit;
+          drug.expiresIn = drug.expiresIn;
+          break;
+        default:
+          this.decreaseExpiresIn(drug);
+          if (drug.benefit > 0) {
+            this.decreaseBenefit(drug);
           }
-        }
       }
-    }
+    });
 
     return this.drugs;
   }

pharmacy.test.js

@@ -1,9 +1,60 @@
 import { Drug, Pharmacy } from "./pharmacy";
 
 describe("Pharmacy", () => {
-  it("should decrease the benefit and expiresIn", () => {
+  it("should decrease the benefit and expiresIn by 1", () => {
     expect(new Pharmacy([new Drug("test", 2, 3)]).updateBenefitValue()).toEqual(
       [new Drug("test", 1, 2)]
     );
+    expect(
+      new Pharmacy([new Drug("Doliprane", 2, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Doliprane", 1, 2)]);
+    expect(
+      new Pharmacy([new Drug("Dafalgan", 2, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Dafalgan", 1, 2)]);
+  });
+
+  it("should increase the benefit by 1 and decrease expiresIn", () => {
+    expect(
+      new Pharmacy([new Drug("Fervex", 12, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", 11, 4)]);
+    expect(
+      new Pharmacy([new Drug("Herbal Tea", 2, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Herbal Tea", 1, 4)]);
+  });
+
+  it("should increase the benefit by 2 when expiresIn less than 11", () => {
+    expect(
+      new Pharmacy([new Drug("Fervex", 9, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", 8, 5)]);
+    expect(
+      new Pharmacy([new Drug("Fervex", 8, 2)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", 7, 4)]);
+  });
+
+  it("should increase the benefit by 3 when expiresIn less than 6", () => {
+    expect(
+      new Pharmacy([new Drug("Fervex", 5, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", 4, 6)]);
+    expect(
+      new Pharmacy([new Drug("Fervex", 4, 2)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", 3, 5)]);
+  });
+
+  it("should the benefit drop to 0 when expiresIn is negative", () => {
+    expect(
+      new Pharmacy([new Drug("Fervex", -1, 2)]).updateBenefitValue()
+    ).toEqual([new Drug("Fervex", -2, 0)]);
+  });
+
+  it("should the benefit increase by 2 when expiresIn is negative", () => {
+    expect(
+      new Pharmacy([new Drug("Herbal Tea", -1, 3)]).updateBenefitValue()
+    ).toEqual([new Drug("Herbal Tea", -2, 5)]);
+  });
+
+  it("should not change benefit nor expiresIn", () => {
+    expect(
+      new Pharmacy([new Drug("Magic Pill", 1, 2)]).updateBenefitValue()
+    ).toEqual([new Drug("Magic Pill", 1, 2)]);
   });
 });