refactoring + add "Dafalgan" feature

.editorconfig

@@ -0,0 +1,6 @@
+[*]
+charset = utf-8
+
+[*.{js, ts, tsx, json, md, css}]
+indent_style = space
+indent_size = 2

.eslintrc.yml

@@ -1,7 +1,10 @@
 env:
   jest: true
   node: true
-parser: babel-eslint
+parser: "@typescript-eslint/parser"
+plugins:
+  - "@typescript-eslint"
 extends:
   - eslint:recommended
   - plugin:prettier/recommended
+  - plugin:@typescript-eslint/recommended

.husky/pre-commit

@@ -0,0 +1,5 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+yarn lint-fix
+yarn test

.husky/pre-push

@@ -0,0 +1,5 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+yarn start
+yarn golden

drug.test.ts

@@ -0,0 +1,119 @@
+import { Drug } from "./drug";
+
+describe("Drug", () => {
+  it("should decrease the benefit and expiresIn", () => {
+    const drug = new Drug("test", 2, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.expiresIn).toEqual(1);
+    expect(drug.benefit).toEqual(1);
+  });
+
+  it("should decrease the benefit as twice once expired", () => {
+    const drug = new Drug("test", 0, 5);
+    drug.updateBenefitValue();
+
+    expect(drug.expiresIn).toEqual(-1);
+    expect(drug.benefit).toEqual(3);
+  });
+
+  it("should not have negative benefit", () => {
+    const drug = new Drug("test", 0, 0);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(0);
+  });
+});
+
+describe('"Herbal Tea" Drug', () => {
+  it("should increase the benefit", () => {
+    const drug = new Drug("Herbal Tea", 2, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.expiresIn).toEqual(1);
+    expect(drug.benefit).toEqual(3);
+  });
+
+  it("should increase the benefit twice as fast once expired", () => {
+    const drug = new Drug("Herbal Tea", 0, 5);
+    drug.updateBenefitValue();
+
+    expect(drug.expiresIn).toEqual(-1);
+    expect(drug.benefit).toEqual(7);
+  });
+
+  it("should not have benefit more than 50", () => {
+    const drug = new Drug("Herbal Tea", 0, 50);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(50);
+  });
+});
+
+describe('"Magic Pill" Drug', () => {
+  it("should not decrease the benefit", () => {
+    const drug = new Drug("Magic Pill", 2, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(2);
+  });
+
+  it("should never expires", () => {
+    const drug = new Drug("Magic Pill", 0, 5);
+    drug.updateBenefitValue();
+
+    expect(drug.expiresIn).toEqual(0);
+  });
+});
+
+describe('"Fervex" Drug', () => {
+  it("should increase the benefit by 1 ten days upper expiration date", () => {
+    const drug = new Drug("Fervex", 11, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(3);
+  });
+
+  it("should increase the benefit by 2 nine days under expiration date and five days upper expiration date", () => {
+    const drug = new Drug("Fervex", 8, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(4);
+  });
+
+  it("should increase the benefit by 3 four days under expiration date", () => {
+    const drug = new Drug("Fervex", 3, 2);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(5);
+  });
+
+  it("should not have benefit more than 50", () => {
+    const drug = new Drug("Fervex", 1, 50);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(50);
+  });
+
+  it("should lose its benefit once expired", () => {
+    const drug = new Drug("Fervex", 0, 50);
+    drug.updateBenefitValue();
+
+    expect(drug.benefit).toEqual(0);
+  });
+});
+
+
+describe('"Dafalgan" Drug', () => {
+  it("should decrease benefit as twice as fast as normal drugs", () => {
+    const dafalgan = new Drug("Dafalgan", 2, 3);
+    dafalgan.updateBenefitValue();
+
+    expect(dafalgan.benefit).toEqual(1);
+
+    const expiredDafalgan = new Drug("Dafalgan", 0, 5);
+    expiredDafalgan.updateBenefitValue();
+
+    expect(expiredDafalgan.benefit).toEqual(1);
+  });
+});

drug.ts

@@ -0,0 +1,127 @@
+const HERBAL_TEA = "Herbal Tea";
+const FERVEX = "Fervex";
+const MAGIC_PILL = "Magic Pill";
+const DAFALGAN = "Dafalgan";
+
+const MAX_BENEFIT = 50;
+const DOUBLE_BENEFIT_UNDER_DAY_EXPIRATION = 10;
+const TRIPLE_BENEFIT_UNDER_DAY_EXPIRATION = 5;
+
+export class Drug {
+  constructor(
+    public name: string,
+    public expiresIn: number,
+    public benefit: number
+  ) {}
+
+  updateBenefitValue(): void {
+    if (this.name === HERBAL_TEA) {
+      this.updateHerbalTeaBenefitValue();
+    } else if (this.name === FERVEX) {
+      this.updateFervexBenefitValue();
+    } else if (this.name === MAGIC_PILL) {
+      this.updateMagicPillBenefitValue();
+    } else if (this.name === DAFALGAN) {
+      this.updateDafalganBenefitValue();
+    } else {
+      this.updateBenefit(-1);
+    }
+
+    this.updateExpiration();
+
+    if (this.expiresIn < 0) {
+      this.updateExpiredBenefitValue();
+    }
+  }
+
+  private updateHerbalTeaBenefitValue(): void {
+    this.updateBenefit(1);
+  }
+
+  private updateFervexBenefitValue(): void {
+    if (this.expiresIn <= TRIPLE_BENEFIT_UNDER_DAY_EXPIRATION) {
+      this.updateBenefit(3);
+    } else if (this.expiresIn <= DOUBLE_BENEFIT_UNDER_DAY_EXPIRATION) {
+      this.updateBenefit(2);
+    } else {
+      this.updateBenefit(1);
+    }
+  }
+
+  private updateMagicPillBenefitValue(): void {
+    // Do nothing: "Magic pill" drug never lose benefit
+  }
+
+  private updateDafalganBenefitValue(): void {
+    this.updateBenefit(-2);
+  }
+
+  private updateExpiration(): void {
+    if (this.name === HERBAL_TEA) {
+      this.updateHerbalTeaExpiration();
+    } else if (this.name === FERVEX) {
+      this.updateFervexExpiration();
+    } else if (this.name === MAGIC_PILL) {
+      this.updateMagicPillExpiration();
+    } else if (this.name === DAFALGAN) {
+      this.updateDafalganExpiration();
+    } else {
+      this.expiresIn -= 1;
+    }
+  }
+
+  private updateHerbalTeaExpiration(): void {
+    this.expiresIn -= 1;
+  }
+
+  private updateFervexExpiration(): void {
+    this.expiresIn -= 1;
+  }
+
+  private updateMagicPillExpiration(): void {
+    // Do nothing: "Magic pill" drug never expires
+  }
+
+  private updateDafalganExpiration(): void {
+    this.expiresIn -= 1;
+  }
+
+  private updateExpiredBenefitValue(): void {
+    if (this.name === HERBAL_TEA) {
+      this.updateExpiredHerbalTeaBenefitValue();
+    } else if (this.name === FERVEX) {
+      this.updateExpiredFervexBenefitValue();
+    } else if (this.name === MAGIC_PILL) {
+      this.updateExpiredMagicPillBenefitValue();
+    } else if (this.name === DAFALGAN) {
+      this.updateExpiredDafalganBenefitValue();
+    } else {
+      this.updateBenefit(-1);
+    }
+  }
+
+  private updateExpiredHerbalTeaBenefitValue(): void {
+    this.updateBenefit(1);
+  }
+
+  private updateExpiredFervexBenefitValue(): void {
+    this.benefit = this.benefit - this.benefit;
+  }
+
+  private updateExpiredMagicPillBenefitValue(): void {
+    // Do nothing: "Magic pill" drug never lose benefit
+  }
+
+  private updateExpiredDafalganBenefitValue(): void {
+    this.updateBenefit(-2);
+  }
+
+  private updateBenefit(value: number): void {
+    const newBenefitValue = this.benefit + value;
+
+    this.benefit =
+      value < 0
+        ? Math.max(0, newBenefitValue)
+        : Math.min(MAX_BENEFIT, newBenefitValue);
+  }
+}

golden.test.ts

@@ -0,0 +1,11 @@
+import "regenerator-runtime/runtime";
+import { readFile } from "fs/promises";
+
+describe("Golden master", () => {
+  it("should expect same app output", async () => {
+    const truth = (await readFile("./output_truth.txt")).toString();
+    const reality = (await readFile("./output.txt")).toString();
+
+    expect(reality).toEqual(truth);
+  });
+});

index.js → index.ts

@@ -1,22 +1,24 @@
-import { Drug, Pharmacy } from "./pharmacy";
 import fs from "fs";
 
+import { Drug } from "./drug";
+import { Pharmacy } from "./pharmacy";
+
 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),
 ];
 const trial = new Pharmacy(drugs);
 
-const log = [];
+const log: string[] = [];
 
 for (let elapsedDays = 0; elapsedDays < 30; elapsedDays++) {
   log.push(JSON.stringify(trial.updateBenefitValue()));
 }
 
 /* eslint-disable no-console */
-fs.writeFile("output.txt", log.toString(), err => {
+fs.writeFile("output.txt", log.toString(), (err) => {
   if (err) {
     console.log("error");
   } else {

jest.config.ts

@@ -0,0 +1,8 @@
+import type { InitialOptionsTsJest } from "ts-jest";
+
+const config: InitialOptionsTsJest = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+};
+
+export default config;

output_truth.txt

@@ -0,0 +1 @@
+[{"name":"Doliprane","expiresIn":19,"benefit":29},{"name":"Herbal Tea","expiresIn":9,"benefit":6},{"name":"Fervex","expiresIn":4,"benefit":43},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":18,"benefit":28},{"name":"Herbal Tea","expiresIn":8,"benefit":7},{"name":"Fervex","expiresIn":3,"benefit":46},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":17,"benefit":27},{"name":"Herbal Tea","expiresIn":7,"benefit":8},{"name":"Fervex","expiresIn":2,"benefit":49},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":16,"benefit":26},{"name":"Herbal Tea","expiresIn":6,"benefit":9},{"name":"Fervex","expiresIn":1,"benefit":50},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":15,"benefit":25},{"name":"Herbal Tea","expiresIn":5,"benefit":10},{"name":"Fervex","expiresIn":0,"benefit":50},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":14,"benefit":24},{"name":"Herbal Tea","expiresIn":4,"benefit":11},{"name":"Fervex","expiresIn":-1,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":13,"benefit":23},{"name":"Herbal Tea","expiresIn":3,"benefit":12},{"name":"Fervex","expiresIn":-2,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":12,"benefit":22},{"name":"Herbal Tea","expiresIn":2,"benefit":13},{"name":"Fervex","expiresIn":-3,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":11,"benefit":21},{"name":"Herbal Tea","expiresIn":1,"benefit":14},{"name":"Fervex","expiresIn":-4,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":10,"benefit":20},{"name":"Herbal Tea","expiresIn":0,"benefit":15},{"name":"Fervex","expiresIn":-5,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":9,"benefit":19},{"name":"Herbal Tea","expiresIn":-1,"benefit":17},{"name":"Fervex","expiresIn":-6,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":8,"benefit":18},{"name":"Herbal Tea","expiresIn":-2,"benefit":19},{"name":"Fervex","expiresIn":-7,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":7,"benefit":17},{"name":"Herbal Tea","expiresIn":-3,"benefit":21},{"name":"Fervex","expiresIn":-8,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":6,"benefit":16},{"name":"Herbal Tea","expiresIn":-4,"benefit":23},{"name":"Fervex","expiresIn":-9,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":5,"benefit":15},{"name":"Herbal Tea","expiresIn":-5,"benefit":25},{"name":"Fervex","expiresIn":-10,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":4,"benefit":14},{"name":"Herbal Tea","expiresIn":-6,"benefit":27},{"name":"Fervex","expiresIn":-11,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":3,"benefit":13},{"name":"Herbal Tea","expiresIn":-7,"benefit":29},{"name":"Fervex","expiresIn":-12,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":2,"benefit":12},{"name":"Herbal Tea","expiresIn":-8,"benefit":31},{"name":"Fervex","expiresIn":-13,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":1,"benefit":11},{"name":"Herbal Tea","expiresIn":-9,"benefit":33},{"name":"Fervex","expiresIn":-14,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":0,"benefit":10},{"name":"Herbal Tea","expiresIn":-10,"benefit":35},{"name":"Fervex","expiresIn":-15,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-1,"benefit":8},{"name":"Herbal Tea","expiresIn":-11,"benefit":37},{"name":"Fervex","expiresIn":-16,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-2,"benefit":6},{"name":"Herbal Tea","expiresIn":-12,"benefit":39},{"name":"Fervex","expiresIn":-17,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-3,"benefit":4},{"name":"Herbal Tea","expiresIn":-13,"benefit":41},{"name":"Fervex","expiresIn":-18,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-4,"benefit":2},{"name":"Herbal Tea","expiresIn":-14,"benefit":43},{"name":"Fervex","expiresIn":-19,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-5,"benefit":0},{"name":"Herbal Tea","expiresIn":-15,"benefit":45},{"name":"Fervex","expiresIn":-20,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-6,"benefit":0},{"name":"Herbal Tea","expiresIn":-16,"benefit":47},{"name":"Fervex","expiresIn":-21,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-7,"benefit":0},{"name":"Herbal Tea","expiresIn":-17,"benefit":49},{"name":"Fervex","expiresIn":-22,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-8,"benefit":0},{"name":"Herbal Tea","expiresIn":-18,"benefit":50},{"name":"Fervex","expiresIn":-23,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-9,"benefit":0},{"name":"Herbal Tea","expiresIn":-19,"benefit":50},{"name":"Fervex","expiresIn":-24,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}],[{"name":"Doliprane","expiresIn":-10,"benefit":0},{"name":"Herbal Tea","expiresIn":-20,"benefit":50},{"name":"Fervex","expiresIn":-25,"benefit":0},{"name":"Magic Pill","expiresIn":15,"benefit":40}]

package.json

@@ -5,28 +5,33 @@
   "author": "inato",
   "license": "MIT",
   "private": true,
+  "main": "index.ts",
   "engines": {
     "yarn": ">=1.7.0",
     "node": "=16.x"
   },
   "scripts": {
     "lint": "eslint .",
+    "lint-fix": "yarn lint --fix",
     "test": "jest",
-    "start": "babel-node index.js"
+    "golden": "jest -- golden.test.ts",
+    "start": "ts-node index.ts",
+    "postinstall": "husky install"
   },
   "devDependencies": {
-    "@babel/cli": "^7.1.0",
-    "@babel/core": "^7.1.0",
-    "@babel/node": "^7.0.0",
-    "@babel/preset-env": "^7.1.0",
-    "babel-core": "^7.0.0-bridge.0",
-    "babel-eslint": "^9.0.0",
-    "babel-jest": "^27.5.1",
-    "eslint": "^8.9.0",
-    "eslint-config-prettier": "^3.1.0",
-    "eslint-plugin-prettier": "^2.6.2",
-    "jest": "24.8.0",
-    "prettier": "^1.14.3",
-    "regenerator-runtime": "^0.12.1"
+    "@types/jest": "27.4.1",
+    "@types/node": "17.0.23",
+    "@typescript-eslint/parser": "5.18.0",
+    "@typescript-eslint/eslint-plugin": "5.18.0",
+    "eslint": "8.13.0",
+    "eslint-config-prettier": "8.5.0",
+    "eslint-plugin-prettier": "4.0.0",
+    "husky": "7.0.4",
+    "jest": "27.5.1",
+    "prettier": "2.6.2",
+    "regenerator-runtime": "0.12.1",
+    "typescript": "4.6.3",
+    "ts-jest": "27.1.4",
+    "ts-node": "10.7.0"
   }
 }