Nodejs authentication middleware not working - node.js

Question

I am learning a new way to authenticate all my APIs using the application-level middleware. I looked into multiple examples. I tried the following code as one of the ways.
Below is my code, I am writing firebase function with the help of necessary fields already there. I use "firebase serve" to host my functions locally.
const express = require('express')
const bodyParser = require('body-parser')
const cookieParser = require('cookie-parser')()
const cors = require('cors')({ origin: true })
const app = express()
const router = express.Router()
app.use(cors)
app.use(cookieParser)
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: false }))
app.use(async (err, req, res, next) => {
console.log('Middleware')
try {
const { authorization } = req.headers
if (!authorization) {
throw new ErrorHandler(401, "User is not unathorized")
}
if (!authorization.startsWith('Bearer')) {
throw new ErrorHandler(401, "User is not unathorized")
}
const split = authorization.split('Bearer ')
if (split.length !== 2) {
throw new ErrorHandler(401, "User is not unathorized")
}
const token = split[1]
const decodedToken = await admin.auth().verifyIdToken(token);
res.setHeader("email", decodedToken.email)
next()
} catch (error) {
console.log("END")
next(error)
}
});
router.get('/', (req, res) => {
res.end(`${Date.now()}`)
})
router.post('/data', async (req, res, next) => {
res.setHeader("Content-Type", "application/json")
console.log('DATA')
try {
// my other logic goes here
res.end()
} catch (error) {
next(error)
}
})
app.use('/api', router)
app.use((err, req, res, next) => {
if (err) {
handleError(err, res);
}
console.log(JSON.stringify(req.body))
});
exports.app = functions.https.onRequest(app)
I have created a cloud function named app. I am using API like this:
http://localhost:5000/app/api/data
I have written a middleware for authorizing all my APIs that are coming. Middleware is fetching bearer token and token is being verified with the help of firebase.
But when I call "/api/data" this API from postman or web the middleware is not called. For debugging purpose I used console.log to check.
My current flow is POSTMAN -> DATA
What I want is:
POSTMAN -> MIDDLEWARE(if authenticated) -> DATA
POSTMAN -> MIDDLEWARE(if not authenticated) -> END
Please let me know what is the issue with my code is.

Answer 1

Remove err parameter from the middleware, You are setting it as an error handler instead of a middleware, this is the reason the code is not getting executed,
Below code will execute the handler every time you access the /api route
const express = require('express')
const bodyParser = require('body-parser')
const cookieParser = require('cookie-parser')()
const cors = require('cors')({ origin: true })
const app = express()
const router = express.Router()
app.use(cors)
app.use(cookieParser)
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: false }))
app.use(async (req, res, next) => {
console.log('Middleware')
try {
const { authorization } = req.headers
if (!authorization) {
throw new ErrorHandler(401, "User is not unathorized")
}
if (!authorization.startsWith('Bearer')) {
throw new ErrorHandler(401, "User is not unathorized")
}
const split = authorization.split('Bearer ')
if (split.length !== 2) {
throw new ErrorHandler(401, "User is not unathorized")
}
const token = split[1]
const decodedToken = await admin.auth().verifyIdToken(token);
res.setHeader("email", decodedToken.email)
next()
} catch (error) {
console.log("END")
next(error)
}
});
router.get('/', (req, res) => {
res.end(`${Date.now()}`)
})
router.post('/data', async (req, res, next) => {
res.setHeader("Content-Type", "application/json")
console.log('DATA')
try {
// my other logic goes here
res.end()
} catch (error) {
next(error)
}
})
app.use('/api', router)
app.use((err, req, res, next) => {
if (err) {
handleError(err, res);
}
console.log(JSON.stringify(req.body))
});
exports.app = functions.https.onRequest(app)