How to build a todo app with React and Firebase Database

rossanodan profile image Rossano D'Angelo ・2 min read

Day 1

📅 11-06-2019
🕐 1h
🏁 Initial setup and getting ready

Initial setup

I’m going to use create-react-app tool to scaffold the project folder. It’s a tool provided by Facebook that allow to easy scaffold a pre-configured starter project.

npx create-react-app todo-app

The initial project consists of

  • node_modules: contains all necessary dependencies. It’s generated scaffolding the app with create-react-app tool (there’s a npm install into it)
  • public: contains few files like the index.html, the application favicon and a manifest that contains few basic application settings
  • src: contains the code
  • .gitignore
  • package.json: there are all the project information like the version, the author and mainly the dependencies the application needs to work properly
  • yarn.lock: contains all the dependencies Yarn needs with relative versions

To run the starter basic application it’s enough to do

cd todo-app
npm start

npm start is one of several pre-configured commands I’m going to use to develop this application. Other commands are:

  • npm test
  • npm build
  • npm eject (stay away from it for now)

Get ready for components

In order to work with a sustainable and scalable structure, I like to keep things separated. I’m going to create two folders for components.

These two folders will contains (surprise) components!
The only difference between them is that a container is a component that manages the application state so it’s a stateful component. Other components are stateless components.

The main component <App />

Let’s create the first component.
I’m going go to move the App.js, App.test.js and App.css into their own folder ./containers/App/:

// App.js
import React, { Component } from 'react';
import './App.css';

class App extends Component {
  render() {
    return (
      <div className="App">

export default App;
/* App.css */
.App {
  text-align: center;

No changes to the App.test.js at the moment.

Update index.js - importing App component - because files location is changed and delete useless files like logo.svg.

The <Todo /> component

Let’s create the <Todo /> component into the ./components folder. Create Todo.js, Todo.test.js and Todo.css.

// Todo.js
import React from 'react';
import './Todo.css';

const todo = () => (
    <div className="Todo">

export default todo;
/* Todo.css */
.Todo {} /* Empty for now */

Todo.test.js is similar to App.test.js:

import React from 'react';
import ReactDOM from 'react-dom';
import Todo from './Todo';

it('renders without crashing', () => {
  const div = document.createElement('div');
  ReactDOM.render(<Todo />, div);

Now I can use the <Todo /> component into the <App /> component, doing:

import React, { Component } from 'react';
import './App.css';

import Todo from '../../components/Todo/Todo';

class App extends Component {
  render() {
    return (
      <div className="App">
        <Todo />

export default App;

Check out the code here

GitHub logo rossanodan / todo-app

Simple to-do app built with React.

This project was bootstrapped with Create React App.

How to run locally

git clone https://github.com/RossanoDan/todo-app.git
cd todo-app
npm install
npm start

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rossanodan profile

Rossano D'Angelo


Application engineer at The LEGO Group. I like reading manga. All my opinions are belong to me.


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