Mastering TypeScript 3 - Third Edition

A service class

The code that we have built to send an email, can be refactored into a single class, which encapsulates all of the setup code for us. The MailService.ts file is as follows:

import * as nodemailer from 'nodemailer'; 
 
export class MailService { 
    private _transporter: nodemailer.Transporter; 
    constructor() { 
        this._transporter = nodemailer.createTransport( 
            `smtp://localhost:1025` 
        ); 
    } 
    sendMail(to: string, subject: string, content: string) { 
        let options = { 
            from: '[e-mail]', 
            to: to, 
            subject: subject, 
            text: content 
        } 
 
        this._transporter.sendMail(  
            options, (error, info) => { 
                if (error) { 
                    return console.log(`error: ${error}`); 
                } 
                console.log(`Message Sent ${info.response}`); 
        }); 
    } 
} 

Here, we have built a class named MailService ...