React Application with JWT Authentication

Overview

This is an example application that serves an ExpressJS JSON api to a React client application. The React application is configured for a basic JWT authentication flow WITHOUT using redux. Great for those of you that are somewhat familiar with Node, Express, and Mongoose, but want to see an implementation of React + React Router with JWT authentication.

The React client app could easily be restructured to keep current user information in a Redux Store. Give it a shot!

Installation + Development

git clone this repository to your local machine.
run npm install from the cloned repo directory.
create a .env file at the root of the application, adjacent to server.js.

The only environment variable you have to declare in development is JWT_SECRET

In the .env file, you can declare the following environment variables: JWT_SECRET, MONGODB_URI, and PORT. For example:
```
JWT_SECRET=BOOOOOOOOOOOOOM
MONGODB_URI=mongodb://localhost/react-express-jwt
PORT=3001
```

It’s recommended that you run the api server on port 3001 while developing locally, as the client app will default to port 3000.
Make sure mongod is running by running… ahem… mongod
From that point you can run the api server either by using nodemon or just running node server.js
Now for the client application. cd client
Install the client app’s dependencies with npm install
From the client directory, run npm start to boot up the client application.
$$$ Profit

Usage

It’s common to identify the user making an authenticated request on the server side. In this application, the verifyToken middleware (declared in /serverAuth.js) decodes a provided token, and makes sure the request is coming from a valid user. When the user is validated, it is added to the req object as req.user.

Here’s an example of how you can access the ‘current user’ from the server side app, assuming a user is logged in and sending an authenticated request:

const express = require('express')
const mySpecialRouter = new express.Router()
// JWT AUTH MIDDLEWARE:
const { verifyToken }  = require('../serverAuth.js')
const Comment = require('../models/Comment.js')
// all routes declared after this middleware require a token
mySpecialRouter.use(verifyToken)
mySpecialRouter.post("/comments", (req, res) => {
  // since this route succeeds 'verifyToken', it has the current user in req.user
  // so we can easily associate new mongo documents to the current user:
  Comment.create({ ...req.body, user: req.user }, (err, comment) => {
    if(err) return console.log(err)
    res.json({ success: true, message: "Comment created.", comment })
  })
})
module.exports = mySpecialRouter

Technologies

React client application business in the front
NodeJS + Express + Mongoose party in the back
React Router 4.*
Milligram CSS so it doesn’t look like garbage
JSON Web Token authentication flow

Important Notes

While the Mongoose user schema enforces email uniqueness, there’s no handler for duplicate user emails on the client side. (A user wouldn’t know why they couldn’t create their account if they came across this scenario).