Testing authentication flows in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Express module correctly.

Express

const express = require([1]);

Drag options to blanks, or click blank then click option'

A"body-parser"

B"express-session"

C"express"

D"cookie-parser"

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong module name like 'express-session' or 'body-parser'.

Forgetting to put the module name in quotes.

You need to import the main Express module using require("express") to create an Express app.

2fill in blank

medium

Complete the code to set up a POST route for login at '/login'.

Express

app.[1]('/login', (req, res) => {
  // login logic
});

Drag options to blanks, or click blank then click option'

Aget

Bpost

Cput

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of POST for login routes.

Using PUT or DELETE which are not typical for login.

Login forms usually send data via POST, so use app.post to handle the login route.

3fill in blank

hard

Fix the error in the middleware usage to parse JSON bodies.

Express

app.use([1].json());

Drag options to blanks, or click blank then click option'

Aexpress

Bbody-parser

Ccookie-parser

Dexpress-session

Attempts:

3 left

💡 Hint

Common Mistakes

Using body-parser.json() without importing body-parser.

Using express-session or cookie-parser which are unrelated.

Express has a built-in json() middleware accessed via express.json() to parse JSON request bodies.

4fill in blank

hard

Fill both blanks to check if a user is authenticated and redirect if not.

Express

function ensureAuth(req, res, next) {
  if (req.[1]) {
    next();
  } else {
    res.[2]('/login');
  }
}

Drag options to blanks, or click blank then click option'

AisAuthenticated()

Bredirect

Csend

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of res.redirect for navigation.

Checking a wrong property on req object.

The method req.isAuthenticated() checks if the user is logged in, and res.redirect() sends the user to the login page if not.

5fill in blank

hard

Fill all three blanks to create a test that sends a POST request to login and checks the response status.

Express

test('POST /login returns 200 on success', async () => {
  const response = await request(app)
    .[1]('/login')
    .send({ username: 'user', password: 'pass' });
  expect(response.[2]).toBe([3]);
});

Drag options to blanks, or click blank then click option'

Apost

Bstatus

C200

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using get() instead of post() for login.

Checking response.statusCode instead of response.status.

Expecting a wrong status code like 404.

Use post() to send the login request, check response.status, and expect it to be 200 for success.