feat: create a Bot class and include Pino logger

Author: targos

jest.config.js

@@ -1,4 +1,7 @@
 module.exports = {
   preset: 'ts-jest',
   testEnvironment: 'node',
-};
+  moduleNameMapper: {
+    '^#src/(.*)$': '<rootDir>/src/$1',
+  },
+};

package-lock.json

@@ -3,14 +3,15 @@
   "version": "0.0.0",
   "private": true,
   "scripts": {
-    "build": "tsc",
+    "build": "tsc -p tsconfig.prod.json",
     "check-types": "tsc --noEmit",
-    "test-only": "jest",
     "heroku-postbuild": "npm run build",
     "lint": "eslint src --ext ts",
     "lint-fix": "npm run lint -- --fix",
     "start": "nodemon --watch \"src/**/*.ts\" -e ts --exec \"ts-node src/bot.ts\"",
-    "test": "npm run test-only && npm run lint && npm run check-types"
+    "test": "npm run test-only && npm run lint && npm run check-types",
+    "test-only": "jest",
+    "test-coverage": "jest --coverage"
   },
   "repository": {
     "type": "git",
@@ -24,11 +25,13 @@
   "dependencies": {
     "discord.js": "^12.3.1",
     "dotenv": "^8.2.0",
-    "make-promises-safe": "^5.1.0"
+    "make-promises-safe": "^5.1.0",
+    "pino": "^6.7.0"
   },
   "devDependencies": {
     "@types/jest": "^26.0.14",
     "@types/node": "^14.11.8",
+    "@types/pino": "^6.3.3",
     "@types/ws": "^7.2.7",
     "@typescript-eslint/eslint-plugin": "^4.4.1",
     "@typescript-eslint/parser": "^4.4.1",

package.json

@@ -1,13 +1,12 @@
 import 'make-promises-safe';
-import { Client } from 'discord.js';
 import * as Dotenv from 'dotenv';
 
+import Bot from './framework/Bot';
+
 Dotenv.config();
 
-const client = new Client();
+const bot = new Bot({ token: process.env.DISCORD_TOKEN });
 
-client.on('ready', () => {
-  console.log('Bot is ready');
+bot.start().then(() => {
+  bot.logger.info('Bot started');
 });
-
-client.login(process.env.DISCORD_TOKEN);

src/bot.ts

@@ -0,0 +1,43 @@
+import { Client } from 'discord.js';
+import pino from 'pino';
+
+export interface BotOptions {
+  token?: string;
+}
+
+export default class Bot {
+  private token?: string;
+  // @ts-expect-error: The client must be constructed when "start()" is called,
+  // because it keeps the process alive.
+  private client: Client;
+  private started = false;
+
+  public logger: pino.Logger;
+
+  public constructor(options: BotOptions = {}) {
+    this.token = options.token;
+    this.logger = pino();
+  }
+
+  public async start(): Promise<void> {
+    if (this.started) {
+      throw new Error('Bot can only be started once');
+    }
+    this.started = true;
+    this.client = new Client();
+    try {
+      await this.client.login(this.token);
+    } catch (error) {
+      this.started = false;
+      throw error;
+    }
+  }
+
+  public stop(): void {
+    if (!this.started) {
+      throw new Error('Bot was not started');
+    }
+    this.client.destroy();
+    this.started = false;
+  }
+}

src/framework/Bot.ts

@@ -0,0 +1,21 @@
+import Bot from '#src/framework/Bot';
+
+const dummyOptions = { token: 'dummy' };
+
+test('bot.start() throws if called with bad token', async () => {
+  const bot = new Bot(dummyOptions);
+  await expect(bot.start()).rejects.toThrow(/invalid token/);
+});
+
+test('bot.start() throws if called twice', async () => {
+  const bot = new Bot(dummyOptions);
+  bot.start().catch(() => {
+    // ignore
+  });
+  await expect(bot.start()).rejects.toThrow(/can only be started once/);
+});
+
+test('bot.stop() throws if it was not started', () => {
+  const bot = new Bot(dummyOptions);
+  expect(() => bot.stop()).toThrow(/was not started/);
+});

tests/framework/Bot.spec.ts

@@ -1,7 +1,16 @@
 {
-  "include": ["src/**/*.ts"],
+  "include": ["src/**/*.ts", "tests/**/*.ts"],
   "compilerOptions": {
+    "target": "ES2020",
+    "lib": ["ES2020"],
     "strict": true,
     "outDir": "build",
+    "moduleResolution": "node",
+    "esModuleInterop": true,
+    "rootDir": "./",
+    "baseUrl": "./",
+    "paths": {
+      "#src/*": ["./src/*"]
+    }
   }
 }

tests/sum.spec.ts

@@ -0,0 +1,4 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": ["tests"]
+}