Firebase with React - Commands & Configuration

Introduction

Firebase is a service that helps you add backend features like databases and user login to your React app without managing servers. It solves the problem of building and scaling app infrastructure easily.

When you want to add user login and authentication to your React app quickly.

When you need a real-time database to sync data between users instantly.

When you want to store files like images or documents from your React app.

When you want to deploy your React app with hosting included.

When you want to track app usage and errors without setting up your own servers.

Config File - firebaseConfig.js

firebaseConfig.js

import { initializeApp } from 'firebase/app';
import { getAuth } from 'firebase/auth';
import { getFirestore } from 'firebase/firestore';

const firebaseConfig = {
  apiKey: "AIzaSyD_example1234567890",
  authDomain: "my-app-12345.firebaseapp.com",
  projectId: "my-app-12345",
  storageBucket: "my-app-12345.appspot.com",
  messagingSenderId: "1234567890",
  appId: "1:1234567890:web:abcdef123456"
};

const app = initializeApp(firebaseConfig);
const auth = getAuth(app);
const db = getFirestore(app);

export { auth, db };

This file sets up Firebase in your React app.

firebaseConfig holds your project details from Firebase console.

initializeApp starts Firebase with your config.

getAuth and getFirestore create services for login and database.

Exporting auth and db lets you use them in your React components.

Commands

This command installs the Firebase library so you can use Firebase features in your React app.

Terminal

npm install firebase

Expected Output

+ firebase@10.4.0

added 1 package from 1 contributor and audited 1 package in 1.234s

found 0 vulnerabilities

This creates a new React app folder named 'my-firebase-app' where you will add Firebase.

Terminal

npx create-react-app my-firebase-app

Expected Output

Creating a new React app in /home/user/my-firebase-app.

Installing packages. This might take a couple of minutes.



Success! Created my-firebase-app at /home/user/my-firebase-app

Inside that directory, you can run several commands:

  npm start

  npm run build

  npm test

  npm eject



We suggest that you begin by typing:

  cd my-firebase-app

  npm start

Starts the React development server so you can see your app in the browser while you build it.

Terminal

npm start

Expected Output

Compiled successfully!



You can now view my-firebase-app in the browser.



  Local:            http://localhost:3000

  On Your Network:  http://192.168.1.100:3000



Note that the development build is not optimized.

To create a production build, use npm run build.

Builds the React app into static files ready for deployment, including Firebase hosting if configured.

Terminal

npm run build

Expected Output

Creating an optimized production build...

Compiled successfully.



File sizes after gzip:

  45.2 KB  build/static/js/main.abcdef.js

  2.1 KB   build/static/css/main.abcdef.css



The project was built assuming it is hosted at the server root.

You can control this with the homepage field in your package.json.

Key Concept

If you remember nothing else from this pattern, remember: Firebase connects your React app to backend services like login and database without needing your own servers.

Common Mistakes

Not installing the Firebase package before importing it in React code.

The app will fail to run because the Firebase library is missing.

Always run 'npm install firebase' before using Firebase in your React app.

Using incorrect Firebase config values copied from the console.

Firebase will not connect properly and features like login or database will fail.

Copy the exact config values from your Firebase project settings and paste them into your config file.

Trying to use Firebase services before calling initializeApp with config.

Firebase services like auth or database won't work without initialization.

Always call initializeApp with your config before using other Firebase features.

Summary

Install Firebase package to use its services in React.

Create a firebaseConfig.js file to initialize Firebase with your project details.

Use npm start to run your React app locally and npm run build to prepare it for deployment.