email-sender-sdn/index.js

Reusable email sender with support for HTML, plain text, templates, and attachments.

const nodemailer = require('nodemailer');
const config = require('./config');
const fs = require('fs');
const path = require('path');
const Handlebars = require('handlebars');

const transporter = nodemailer.createTransport({
  host: config.host,
  port: config.port,
  secure: config.secure,
  auth: config.auth,
});

function renderTemplate(templateName, data) {
  const filePath = path.join(__dirname, 'templates', `${templateName}.hbs`);
  const source = fs.readFileSync(filePath, 'utf8');
  const compiledTemplate = Handlebars.compile(source);
  return compiledTemplate(data);
}

/**
 * Send an email with dynamic options
 * @param {Object} options
 * @param {string} options.to - Recipient
 * @param {string} options.subject - Subject
 * @param {string} [options.text] - Plain text content
 * @param {string} [options.html] - Raw HTML content
 * @param {Object} [options.template] - { name: 'templateName', data: { … } }
 * @param {Array} [options.attachments] - Attachments array
 */
async function sendEmail({ to, subject, text, html, template, attachments = [] }) {
  let finalHtml = html;

  if (!html && template?.name) {
    finalHtml = renderTemplate(template.name, template.data || {});
  }

  const mailOptions = {
    from: config.from,
    to,
    subject,
    text,
    html: finalHtml,
    attachments,
  };

  return transporter.sendMail(mailOptions);
}

module.exports = { sendEmail };