JWT overview

app.js

const express = require("express");
const jwt = require("jsonwebtoken");

const app = express();

app.get("/api", (req, res) => {
  res.json({
    message: "Welcome to the API",
  });
});

app.post("/api/posts", verifyToken, (req, res) => {
  jwt.verify(req.token, "secretKey", (err, authData) => {
    if (err) res.sendStatus(403);
    else {
      res.json({
        message: "Post created",
        authData,
      });
    }
  });
});

app.post("/api/login", (req, res) => {
  // Mock user
  const user = { id: 1, username: "brad", email: "brad@gmail.com" };

  jwt.sign({ user }, "secretKey", (err, token) => {
    res.json({
      token,
    });
  });
});

// verify Token
// FORMAT ->  Authorization : Bearer <access_token>

function verifyToken(req, res, next) {
  // Get auth header value
  const bearerHeader = req.headers["authorization"];
  console.log(req.headers);
  // check if bearer is undefined
  if (typeof bearerHeader !== "undefined") {
    // spilt at space
    const bearer = bearerHeader.split(" ");
    // Get token from array
    const bearerToken = bearer[1];

    req.token = bearerToken;
    next();
  } else {
    res.sendStatus(403);
  }
}

app.listen(5000, () => console.log("server started"));