Let's look at how we can add authentication. To work with JWT, we'll be using jsonwebtoken from https://github.com/auth0/node-jsonwebtoken. Install it with the help of the following command:
npm install jsonwebtoken --save
Our code example for JWT will be larger than in previous examples, and it should be separated into many files. However, I avoided doing this in order to make it clearer. First, we'll need to make some declarations, and the key lines are in bold:
// Source file: src/jwt_server.js/* @flow */"use strict";const express = require("express");const app = express();const jwt = require("jsonwebtoken");const bodyParser = require("body-parser");const validateUser = require("./validate_user.js");const SECRET_JWT_KEY ...
