Firebase cloud functions

index.js

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

// Create a function that trigger by HTTP

exports.helloWorld = functions.https.onRequest((request, response) => {
  // console.log/info/warn/error will send the message to Cloud Logging
  console.log('In helloworld!');
  response.send("Hello from Firebase!");
});

// The Firebase Admin SDK to access the Firebase Realtime Database.
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

// Take the text parameter passed to this HTTP endpoint and insert it into the
// Realtime Database under the path /messages/:pushId/original
exports.addMessage = functions.https.onRequest((req, res) => {
  // Grab the text parameter.
  const original = req.query.text;
  console.log(`original = ${original}`);
  // Push the new message into the Realtime Database using the Firebase Admin SDK.
  admin.database().ref('/messages').push({original: original}).then(snapshot => {
    // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
    console.log(`ref = ${snapshot.ref}`);
    res.redirect(303, snapshot.ref);
  });
});

// Listens for new messages added to /messages/:pushId/original and creates an
// uppercase version of the message to /messages/:pushId/uppercase
exports.makeUppercase = functions.database.ref('/messages/{pushId}/original')
.onWrite(event => {
  // Grab the current value of what was written to the Realtime Database.
  const original = event.data.val();
  console.log('Uppercasing', event.params.pushId, original);
  const uppercase = original.toUpperCase();
  // You must return a Promise when performing asynchronous tasks inside a Functions such as
  // writing to the Firebase Realtime Database.
  // Setting an "uppercase" sibling in the Realtime Database returns a Promise.
  return event.data.ref.parent.child('uppercase').set(uppercase);
});