app.js

/**
 * Copyright 2019, Google LLC.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

'use strict';

const express = require('express');
const bodyParser = require('body-parser').urlencoded({
  extended: false,
});

const app = express();

const {TWILIO_NUMBER} = process.env;
if (!TWILIO_NUMBER) {
  console.log(
    'Please configure environment variables as described in README.md'
  );
  throw new Error(
    'Please configure environment variables as described in README.md'
  );
}

const Twilio = require('twilio');

const twilioClient = Twilio(
  process.env.TWILIO_ACCOUNT_SID,
  process.env.TWILIO_AUTH_TOKEN
);

const {TwimlResponse} = Twilio;

// [START gae_flex_twilio_receive_call]
app.post('/call/receive', (req, res) => {
  const resp = new TwimlResponse();
  resp.say('Hello from Google App Engine.');

  res
    .status(200)
    .contentType('text/xml')
    .send(resp.toString());
});
// [END gae_flex_twilio_receive_call]

// [START gae_flex_twilio_send_sms]
app.get('/sms/send', async (req, res, next) => {
  const {to} = req.query;
  if (!to) {
    res
      .status(400)
      .send('Please provide an number in the "to" query string parameter.');
    return;
  }

  try {
    await twilioClient.messages.create({
      to: to,
      from: TWILIO_NUMBER,
      body: 'Hello from Google App Engine',
    });
    res.status(200).send('Message sent.');
  } catch (err) {
    next(err);
    return;
  }
});
// [END gae_flex_twilio_send_sms]

// [START gae_flex_twilio_receive_sms]
app.post('/sms/receive', bodyParser, (req, res) => {
  const sender = req.body.From;
  const body = req.body.Body;

  const resp = new TwimlResponse();
  resp.message(`Hello, ${sender}, you said: ${body}`);

  res
    .status(200)
    .contentType('text/xml')
    .send(resp.toString());
});
// [END gae_flex_twilio_receive_sms]

// Start the server
if (module === require.main) {
  const PORT = process.env.PORT || 8080;
  app.listen(PORT, () => {
    console.log(`App listening on port ${PORT}`);
    console.log('Press Ctrl+C to quit.');
  });
}

exports.app = app;