cors middleware setup in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the CORS middleware.

Express

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

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

Aexpress

Bcors

Chttp

Dbody-parser

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of 'cors' in require statement.

Forgetting to import the CORS middleware.

The CORS middleware is imported using require('cors').

2fill in blank

medium

Complete the code to apply CORS middleware globally in the Express app.

Express

app.use([1]());

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

Acors

Bexpress

CbodyParser

Dhelmet

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express()' instead of 'cors()' in app.use.

Not calling the middleware function with parentheses.

Use cors() as middleware to enable CORS for all routes.

3fill in blank

hard

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

Express

app.use(cors({ origin: [1] }));

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

Afalse

B'*'

Ctrue

D'https://example.com'

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' allows all origins, not just the specific one.

Using boolean values instead of a string URL.

Setting origin to the specific URL string restricts CORS to that domain.

4fill in blank

hard

Fill both blanks to configure CORS to allow credentials and restrict origin to 'https://myapp.com'.

Express

app.use(cors({ origin: [1], [2]: true }));

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

A'https://myapp.com'

B'*'

Ccredentials

Dmethods

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' for origin when restricting to a specific domain.

Using 'methods' instead of 'credentials' to allow credentials.

Set origin to the allowed URL and credentials to true to allow cookies and auth headers.

5fill in blank

hard

Fill all three blanks to create a CORS middleware that allows origin 'https://site.com', credentials, and only GET and POST methods.

Express

app.use(cors({ origin: [1], [2]: true, [3]: ['GET', 'POST'] }));

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

A'https://site.com'

Bcredentials

Cmethods

D'*'

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' for origin when restricting to a specific domain.

Omitting the credentials option when cookies are needed.

Using incorrect option names like 'methodsAllowed' instead of 'methods'.

Set origin to the allowed URL, credentials to true, and methods to the allowed HTTP methods array.