CORS configuration in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the CORS middleware in a Node.js Express app.

Node.js

const express = require('express');
const cors = require('[1]');
const app = express();

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

Abody-parser

Bexpress

Chttp

Dcors

Attempts:

3 left

💡 Hint

Common Mistakes

Importing 'express' instead of 'cors'.

Forgetting to install the 'cors' package.

The cors package is imported to enable CORS middleware in Express.

2fill in blank

medium

Complete the code to enable CORS for all routes in the Express app.

Node.js

app.use([1]());

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

Aexpress

BbodyParser

Ccors

Dhelmet

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express()' instead of 'cors()' as middleware.

Not calling the middleware as a function.

Using cors() as middleware enables CORS for all routes.

3fill in blank

hard

Fix the error in the CORS options object to allow only 'https://example.com'.

Node.js

const corsOptions = {
  origin: [1]
};

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

A'https://example.com'

B'*'

C['https://example.com']

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using an array instead of a string for a single origin.

Using '*' which allows all origins.

The origin option should be a string with the allowed domain.

4fill in blank

hard

Fill both blanks to apply CORS middleware with options and start the server on port 3000.

Node.js

app.use([1](corsOptions));
app.listen([2], () => console.log('Server running'));

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

Acors

Bexpress

C3000

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of 'cors' for middleware.

Using wrong port number.

Use cors(corsOptions) to apply CORS with options, and listen on port 3000.

5fill in blank

hard

Fill all three blanks to create a CORS options object allowing methods GET and POST, origin 'https://site.com', and enable credentials.

Node.js

const corsOptions = {
  origin: [1],
  methods: [2],
  credentials: [3]
};

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

A'https://site.com'

B['GET', 'POST']

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of an array for methods.

Setting credentials to false when true is needed.

The origin is a string, methods is an array of allowed methods, and credentials is a boolean.