Node email send

email-client.ts

import * as nodemailer from 'nodemailer';
import * as fs from 'fs';
import handlebars from 'handlebars';
import Mail from 'nodemailer/lib/mailer';

type EmailClientArgs<TemplateData> = {
  to: string;
  subject: string;
  templatePath: string;
  templateData: TemplateData;
};

const sendMail = async <TemplateData>(data: EmailClientArgs<TemplateData>) => {
  const fromEmailAddress = process.env.FROM_EMAIL;
  const smtpHost = process.env.STMP_HOST ?? '';
  const smtpPort = parseInt(process.env.STMP_PORT ?? '587', 10);
  const smtpUser = process.env.STMP_USER ?? '';
  const smtpPassword = process.env.STMP_PASSWORD ?? '';

  try {
    const smtpTransport: Mail = nodemailer.createTransport({
      host: smtpHost,
      port: smtpPort,
      auth: {
        user: smtpUser,
        pass: smtpPassword,
      },
    });

    const source = fs.readFileSync(data.templatePath, { encoding: 'utf-8' });
    const template: HandlebarsTemplateDelegate<TemplateData> = handlebars.compile(source);
    const html: string = template(data.templateData);

    const updatedData: Mail.Options = {
      to: data.to,
      html,
      from: `Awesome App <${fromEmailAddress}>`,
      subject: data.subject,
    };

    smtpTransport.sendMail(updatedData).then((result: nodemailer.SentMessageInfo): void => {
      console.info(result);
    });
  } catch (e) {
    console.error(e);
  }
};

export { sendMail };

index.ts

type ConfirmEmailPayload = {
  email: string;
  name: string;
  url: string;
};

app.post('/register', async (req, res) => {
  const { email, name } = req.body;

  // TODO Save user into the database

  const templateData: ConfirmEmailPayload = {
    email,
    name,
    url: 'generated_confirmation_url',
  };

  sendMail<ConfirmEmailPayload>({
    subject: 'Confirm your account',
    templateData,
    templatePath: path.join(__dirname, './email-template/confirm-account.html'),
    to: email,
  });

  return res.send({ message: 'User created successfully.' });
});