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Killian Frappart
Killian Frappart

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Instant messaging app made with React, Typescript, Node & 🦜

Hello everyone, I am back on today to share another of my project!

We all know how important it is to practice regularly in order to improve our development skills. As I am getting more confident, I try to build more complex and robust applications.

This last project was a lot of fun to build. It took me almost a month to deploy it (I mainly work after school hours).

Enjoy reading 😇

Table of contents

  1. Project Introduction
  2. Features
  3. Tech Stack
  4. Wireframe & Design
  5. Data modeling & API routing
  6. Project Organization
  7. Sprint 01: Frontend
  8. Sprint 02: Backend
  9. Sprint 03: Fix & Deploy
  10. Conclusion

Project Introduction 👋

I am glad to introduce GroupChat 🥳

This challenge's wireframes are provided by devchallenges which offers many cool ideas of projects to build and practice. Take a look if you are missing inspiration!

Ok, let's talk about GroupChat, it is an instant messaging app that allows users to create channels and chat with people interested in a particular topic.

Sounds simple ? Well, I would not say that it was "complicated" but it is always challenging to try something new.

It was the first time I have worked with and it was also my first medium-sized project built with TypeScript.

Features 🌟

✅ Custom Authentication (Email - Password)
✅ Login as guest (limited access)
✅ Random Avatar / Profile image upload
✅ Authorization (json web tokens)
✅ End to End input validation
✅ Create and join channels
✅ Instant messaging
✅ Bug report
✅ Mobile friendly

Tech Stack ⚛️

Once again, I went for my best friend the MERN stack which includes:
➡️ MongoDB
➡️ Express
➡️ React
➡️ Node

In addition to above technologies, I worked with TypeScript to improve the robustness of my code and with Redux to manage the app state.

I should also mention that enables real-time, bidirectional and event-based communication between the browser and the server.

For deployment, an easy and efficient way is to host the frontend on Netlify and backend with Heroku.

Here is a list of tools I usually work with to enhance my programming experience:
➡️ OS: MacOS
➡️ Terminal: iterm2
➡️ IDE:VSCode
➡️ Versioning: Git
➡️ Package Manager: NPM
➡️ Project Organization: Notion

Wireframe & Design 🎨

To be honest, I don't have too much pleasure designing a product's UI. So, I decided to work with existing wireframes and focus on the code instead.

As I said already, I inspired from devchallenges. Quick overview:

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Data modeling & API routing 💾

Database design and API routing are important steps. Make sure you have an action plan before starting coding, or it will be a disaster 🧨

Here is a simple data model made with Lucidchart:

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It is indeed simple, but it is enough for this project.

As you could guess, we are building a REST API with Node/Express which involves HTTP requests.

Let's imagine our routes:

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Note: API doc made with Apiary

Project Organization 🗂️

I love when everything is clean and well-organized. Here is the folder structure I decided to work with:

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Simple, clean and consistent 💫

In order to keep track of my progress, I made myself a task board on Trello

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Before you head over to the next step, I will briefly talk about the Git workflow.

As I was the only one working on this project, GitHub flow worked just fine.

Every addition to the code has a dedicated branch and the code is reviewed (by myself only...) for each new PR.

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Note: Around 180 commits and 40 branches were created

Sprint 01: Setup & Frontend 🖥

It is always so exciting to start coding, this is my favorite part of the process.

I would say that the first week was the easiest.I began with setting up both Frontend and Backend which means install dependencies, environment variables, CSS reset, create a database, ...

Once setup is done, I built every single component that should appear on the screen and made sure they are mobile friendly (flex, media queries, ...).

Speaking of components and UI, here is a simple example:

// TopBar/index.tsx
import React from 'react';
import { IconButton } from '@material-ui/core';
import MenuIcon from '@material-ui/icons/Menu';

// Local Imports
import styles from './styles.module.scss';

type Props = {
  title?: String;
  menuClick: () => void;

const TopBar: React.FC<Props> = props => {
  return (
    <div className={styles.container}>
      <div className={styles.wrapper}>
        <IconButton className={styles.iconButton} onClick={props.menuClick}>
          <MenuIcon className={} fontSize="large" />
        <h2 className={styles.title}>{props.title}</h2>

export default TopBar;
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// TopBar/styles.module.scss
.container {
  width: 100%;
  height: 60px;
  box-shadow: 0px 4px 4px rgba($color: #000, $alpha: 0.2);
  display: flex;
  align-items: center;
  justify-content: center;

.wrapper {
  width: 95%;
  display: flex;
  align-items: center;

.title {
  font-size: 18px;

.iconButton {
  display: none !important;
  @media (max-width: 767px) {
    display: inline-block !important;

.menu {
  color: #e0e0e0;

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Nothing fancy, it is a basic implementation of TypeScript (I still have a lot to learn) and SCSS modules.

I like SCSS a lot and wrote an introduction for anyone interested:

You can also notice that some components (icons, inputs, ...) are imported from my favorite UI library out there: Material UI.

Speaking of TypeScript, the first days were really painful and tiring but in the end, it appeared to be extremely easy to catch bugs during development.

If you find struggling with TypeScript, you may want to have a look to this post:

I am not so familiar with Redux and I had to spend some time reading the doc in order to make it right.

Another cool tool I worked with is Formik which manages form validation in a smart and simple way.

Alt Text

// Login/index.tsx

import React, { useState } from 'react';
import { Link } from 'react-router-dom';
import axios from 'axios';
import { TextField, FormControlLabel, Checkbox, Snackbar, CircularProgress } from '@material-ui/core';
import MuiAlert from '@material-ui/lab/Alert';
import { useDispatch } from 'react-redux';
import { useFormik } from 'formik';
import * as Yup from 'yup';
import { useHistory } from 'react-router-dom';

// Local Imports
import logo from '../../../assets/gc-logo-symbol-nobg.png';
import CustomButton from '../../Shared/CustomButton/index';
import styles from './styles.module.scss';

type Props = {};

type SnackData = {
  open: boolean;
  message: string | null;

const Login: React.FC<Props> = props => {
  const dispatch = useDispatch();
  const history = useHistory();

  const [isLoading, setIsLoading] = useState(false);
  const [checked, setChecked] = useState(false);
  const [snack, setSnack] = useState<SnackData>({ open: false, message: null });

  // Async Requests
  const loginSubmit = async (checked: boolean, email: string, password: string) => {
    let response;
    try {
      response = await`${process.env.REACT_APP_SERVER_URL}/users/login`, {
        email: email.toLowerCase(),
        password: password.toLowerCase()
    } catch (error) {
      console.log('[ERROR][AUTH][LOGIN]: ', error);
    if (! {
      setSnack({ open: true, message: });
    if (checked) {
      localStorage.setItem('userData', JSON.stringify({ id:, token: }));
    dispatch({ type: 'LOGIN', payload: { } });

  const formik = useFormik({
    initialValues: {
      email: '',
      password: ''
    validationSchema: Yup.object({
      email: Yup.string().email('Invalid email address').required('Required'),
      password: Yup.string()
        .min(6, 'Must be 6 characters at least')
        .max(20, 'Can not exceed 20 characters')
    onSubmit: values => loginSubmit(checked,, values.password)

  return (
    <div className={styles.container}>
      <Link to="/">
        <img className={styles.logo} alt="logo" src={logo} />
      <form className={styles.form}>
          helperText={ &&}
          error={ && !!}
          helperText={formik.touched.password && formik.errors.password}
          error={formik.touched.password && !!formik.errors.password}
            <Checkbox checked={checked} onChange={() => setChecked(prev => !prev)} name="checked" color="primary" />
          label="Remember me"
        <CustomButton type="submit" onClick={formik.handleSubmit} isPurple title="Login" small={false} />
      <Link to="/signup">
        <p className={styles.guest}>Don't have an account? Sign Up</p>
      {isLoading && <CircularProgress />}
      <Snackbar open={} onClose={() => setSnack({ open: false, message: null })} autoHideDuration={5000}>
        <MuiAlert variant="filled" onClose={() => setSnack({ open: false, message: null })} severity="error">

export default Login;
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Sprint 02: Backend 📊

The server is pretty straightforward, it is a classic representation of what a Node/Express server should look like.

I created mongoose models and their associations.

Then, I registered routes and connected corresponding controllers. Inside my controllers, you can find classic CRUD operations and some custom functions.

Thanks to JWT, it was possible to work on the security, which was an important point for me.

Now comes the coolest feature of this app, bidirectional communication or maybe should I say ?

Here is an example:

Alt Text

// app.js - Server side

// Establish a connection
io.on('connection', socket => {
  // New user
  socket.on('new user', uid => {
    userList.push(new User(uid,;

  // Join group
  socket.on('join group', (uid, gid) => {
    for (let i = 0; i < userList.length; i++) {
      if ( === userList[i].sid) userList[i].gid = gid;

  // New group
  socket.on('create group', (uid, title) => {
    io.emit('fetch group');

  // New message
  socket.on('message', (uid, gid) => {
    for (const user of userList) {
      if (gid === user.gid)'fetch messages', gid);

  // Close connection
  socket.on('disconnect', () => {
    for (let i = 0; i < userList.length; i++) {
      if ( === userList[i].sid) userList.splice(i, 1);

// AppView/index.tsx - Client side

  useEffect(() => {
    const socket = socketIOClient(process.env.REACT_APP_SOCKET_URL!, { transports: ['websocket'] });
    socket.emit('new user',;
    socket.on('fetch messages', (id: string) => fetchMessages(id));
    socket.on('fetch group', fetchGroups);
  }, []);
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I discovered express-validator and it helped a lot to provide input validation on the server side. With no doubt, a library that I am going to use again.

Sprint 03: Fix & Deploy ☁️

Alright, the app is looking good and features are working fine. It is time to finish this portfolio project and start a new one.

I am not a pro of cloud solution and complex CI/CD methods so I will satisfy with a free hosting service.

Heroku has a free solution that works fine for the backend. 5 minutes after my node server was uploaded, it was running independantly. Awesome 🌈

I experienced some security issues with the client. Usually, everything is ok when I send my React app to Netlify via GitHub but not this time.

Many of my friends could not reach the given URL because of some "security reasons" and I had to buy a domain name to fix it. No big deal here, 15 euros for a year does not seem overpriced.

Finally, images uploaded by users are stored on my Cloudinary account via their public API.

Conclusion ✅

Once again, I enjoyed myself so much working on this project and learned a lot.

It was a pleasure to share the process with you and I can't wait to hear your tips and feedbacks.

This project is nothing more than a portfolio project and there is no "production" intention behind. However, the code is open sourced on GitHub, feel free to do whatever you want with it.

GitHub logo KillianFrappartDev / GroupChat

Instant messaging webapp project made with React, Redux, TypeScript, Node, MongoDB &

I know that there is a lot to improve in term of code quality, security, optimization, ... Whatever, I managed to finish this and the result looks pretty cool and I hope you like it as well.

Live version: GroupChat

Never stop challenging yourself 🚀

Top comments (14)

bartosz profile image
Bartosz Wójcik

Now add end-to-end encryption :)

yoel3imari profile image
يوسف العيماري


shwetabh1 profile image
Shwetabh Shekhar

Excellent article, well done!

andrewbaisden profile image
Andrew Baisden

Nicccceeee! 🔥

cross profile image
Vitaliy Derda

Very good job!

aalphaindia profile image
Pawan Pawar

Great article, well done!

auloryn profile image

Good job!

killianfrappartdev profile image
Killian Frappart

I did my best, thanks for reading!

longreede profile image
de Longrée Laureline

Great article, well done!

killianfrappartdev profile image
Killian Frappart

Thank you 😇

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