mouredev#30 - TypeScript

Roadmap/30 - SOLID DIP/typescript/Sac-Corts.ts

@@ -0,0 +1,103 @@
+// Wrong way
+class UserService {
+    private database: MySQLDatabase;
+
+    constructor() {
+        this.database = new MySQLDatabase();
+    }
+
+    getUser(id: number) {
+        return this.database.findUserById(id);
+    }
+}
+
+class MySQLDatabase {
+    findUserById(id: number) {
+        return { id, name: 'Isaac Cortés', db: 'MySQL' };
+    }
+}
+
+const userService = new UserService();
+console.log(userService.getUser(1));
+
+// Correct way
+class UserService2 {
+    private database: Database;
+
+    constructor(database: Database) {
+        this.database = database;
+    }
+
+    getUser(id: number) {
+        return this.database.findUserById(id);
+    }
+}
+
+abstract class Database {
+    abstract findUserById(id: number): { id: number; name: string; db: string };
+}
+
+class MySQLDatabase2 extends Database {
+    findUserById(id: number) {
+        return { id, name: 'Isaac Cortés', db: 'MySQL' };
+    }
+}
+
+class MongoDBDatabase extends Database {
+    findUserById(id: number) {
+        return { id, name: 'Isaac Cortés', db: 'MongoDB' };
+    }
+}
+
+const mysqlService = new UserService2(new MySQLDatabase2());
+console.log(mysqlService.getUser(1));
+
+const mongoService = new UserService2(new MongoDBDatabase());
+console.log(mongoService.getUser(2));
+
+// ** Extra Exercise ** //
+abstract class NotificationService {
+    abstract sendNotification(message: string, recipient: string): void;
+}
+
+class EmailNotification extends NotificationService {
+    sendNotification(message: string, recipient: string): void {
+        console.log(`Sending email to ${recipient}: ${message}`);
+    }
+}
+
+class PushNotification extends NotificationService {
+    sendNotification(message: string, recipient: string): void {
+        console.log(`Sending push to ${recipient}: ${message}`);
+    }
+}
+
+class SMSNotification extends NotificationService {
+    sendNotification(message: string, recipient: string): void {
+        console.log(`Sending SMS to ${recipient}: ${message}`);
+    }
+}
+
+class NotificationManager {
+    private notificationService: NotificationService;
+
+    constructor(notificationService: NotificationService) {
+        this.notificationService = notificationService;
+    }
+
+    send(message: string, recipient: string): void {
+        this.notificationService.sendNotification(message, recipient);
+    }
+}
+
+const emailService = new EmailNotification();
+const pushService = new PushNotification();
+const smsService = new SMSNotification();
+
+const emailManager = new NotificationManager(emailService);
+const pushManager = new NotificationManager(pushService);
+const smsManager = new NotificationManager(smsService);
+
+emailManager.send('Hello, Isaac!', '[email protected]');
+pushManager.send('Hello, Isaac!', 'sac');
+smsManager.send('Hello, Isaac!', '8992584897');