Explore Firebase Cloud Functions

Introduction:

Firebase, Backend as a service, released a new feature Cloud Functions. It allows developers write back-end code without worrying handling a server. In the following blog post, I explored how fast it is to create a simple HTTP request listener.

1. Install the Firebase CLI tools:

npm install -g firebase-tools

2. Login with Google account:

firebase login

3. Initialize a Firebase project:

firebase init

4. Select features with number keys [1,2,3]:

5. Select Firebase project:

After the initialization, the following files structure will be created:

The Cloud Functions can then be defined in the index.js file. Note that ES6 is used.

6. Deploy the functions:

7. Test it!

The Firebase console should show the deployed function:

And it can be tested via postman:

8 Different Request Methods

Different HTTP methods (GET POST etc.) of a route can be defined as follows:

9. Refactoring

Having many functions in one index.js file is not desired. Therefore I created Handler classes for handling logic.

Index.js (managing all the routes):

// imports
const functions = require('firebase-functions');
// handlers
const HellowordHandler = require('./handlers/helloword');
const hellowordHandler = new HellowordHandler('DEV');
// routes
exports.helloWorld = functions.https.onRequest(hellowordHandler.handle.bind(hellowordHandler));

helloword.js (the logic in ES6 class):

class HelloWordHandler {
  constructor(env) {
    console.log(`Env: ${env}`);
  }
  handle(request, response) {
    switch (request.method) {
      case 'GET':
        this.getRequest(request, response);
        break;
      case 'POST':
        this.postRequest(request, response);
        break;
      default:
        response.status(403).send('Not support.');
        break;
    }
  }
  getRequest(request, response) {
    response.send('GET request');
  }
  postRequest(request, response) {
    console.log(request.body);
    response.send(request.body);
  }
}
module.exports = HelloWordHandler;

In this way, we can separate different logic to multiple files. In this just my first try to refactor it, if anyone has any suggests, please feel free to leave a comment :D.