Firebase Cloud Functions HTTP Trigger to send confirmation email utilizing SendGrid

send-email-confirmation_index.js

'use strict';


const functions = require('firebase-functions');

const sgMail = require('@sendgrid/mail');
sgMail.setApiKey("SEND_GRID_API_KEY"); /** replace with your own SendGrid API key */

const cors = require('cors')({
  origin: ['ANGULAR_DEVELOPMENT_ENVIRONMENT_URL'], /** replace with the url of your development environment that serves your angular app. */
  methods: ['POST', 'OPTIONS'],
  allowedHeaders: ['Content-Type'],
  preflightContinue: false,
  optionsSuccessStatus: 204
});



exports.sendEmailConfirmation = functions.https.onRequest((req, res) => {
  
  cors(req, res, () => {
    
    return Promise.resolve()
      .then(() => {
        if (req.method !== 'POST') {
          const error = new Error('Only POST requests are accepted');
          error.code = 405;
          throw error;
        }
  
        const message = {
          to: req.body.to,
          from: req.body.from,
          subject: req.body.subject,
          text: req.body.text,
          html: req.body.html
        };
    
        return sgMail.send(message);
        
      })
      .then((response) => {
        if (response.body) {
          res.send(response.body);
        } else {
          res.end();
        }
      })
      .catch((err) => {
        console.error(err);
        return Promise.reject(err);
      });
      
  });
  
});